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Anthracite is a mineral coal which burns almost without flame. Black, hard and brittle, it has a high degree of metamorphism. It is used to heat water in boilers to produce steam to propel turbines in power plants. In the past anthracite was the power source of locomotives and steam ships. It is also used in the production of semiconductors and electrodes.	<urn:uuid:98165d52-2900-48e5-9663-823c2db829ff>	3.015625	80	Knowledge Article	Science & Tech.	52.339323	95,577,435
Primeval lava flows formed the massive canyons and gorge systems on Mars. Water, by contrast, was far too scarce on the red planet to have cut these gigantic valleys into the landscape. This is the conclusion of several years of study by ETH geoscientist Giovanni Leone. An Italian astronomer in the 19th century first described them as ‘canali’ – on Mars’ equatorial region, a conspicuous net-like system of deep gorges known as the Noctis Labyrinthus is clearly visible. The gorge system, in turn, leads into another massive canyon, the Valles Marineris, which is 4,000 km long, 200 km wide and 7 km deep. Both of these together would span the US completely from east to west. As these gorges, when observed from orbit, resemble terrestrial canyons formed by water, most researchers assumed that immense flows of water must have carved the Noctis Labyrinthus and the Valles Marineris into the surface of Mars. Another possibility was that tectonic activity had created the largest rift valley on a planet in our solar system. These assumptions were far from the mark, says Giovanni Leone, a specialist in planetary volcanism in the research group of ETH professor Paul Tackley. Only lava flows would have had the force and mass required to carve these gigantic gorges into the surface of Mars. The study was recently published in the Journal of Volcanology and Geothermal Research. In recent years, Leone has examined intensively the structure of these canyons and their outlets into the Ares Vallis and the Chryse Planitia, a massive plain on Mars’ low northern latitude. He examined thousands of high-resolution surface images taken by numerous Mars probes, including the latest from the Mars Reconnaissance Orbiter, and which are available on the image databases of the US Geological Survey. His conclusion is unequivocal: “Everything that I observed on those images were structures of lava flows as we know them on Earth,” he emphasises. "The typical indicators of erosion by water were not visible on any of them.” Leone therefore does not completely rules out water as final formative force. Evidence of water, such as salt deposits in locations where water evaporated from the ground or signs of erosion on the alluvial fans of the landslides, are scarce but still existing. “One must therefore ask oneself seriously how Valles Marineris could have been created by water if one can not find any massive and widespread evidence of it.” The Italian volcanologist similarly could find no explanation as to where the massive amounts of water that would be required to form such canyons might have originated. The explanatory model presented by Leone in his study illustrates the formation history from the source to the outlet of the gorge system. He identifies the volcanic region of Tharsis as the source region of the lava flows and from there initial lava tubes stretched to the edge of the Noctis Labyrinthus. When the pressure from an eruption subsided, some of the tube ceilings collapsed, leading to the formation of a chain of almost circular holes, the ‘pit chains’. When lava flowed again through the tubes, the ceilings collapsed entirely, forming deep V-shaped troughs. Due to the melting of ground and rim material, and through mechanical erosion, the mass of lava carved an ever-deeper and broader bed to form canyons. The destabilised rims then slipped and subsequent lava flows carried away the debris from the landslides or covered it. “The more lava that flowed, the wider the canyon became,” says Leone. Leone supported his explanatory model with height measurements from various Mars probes. The valleys of the Noctis Labyrinthus manifest the typical V-shape of ‘young’ lava valleys where the tube ceilings have completely collapsed. The upper rims of these valleys, however, have the same height. If tectonic forces had been at work, they would not be on the same level, he says. The notion of water as the formative force, in turn, is undermined by the fact that it would have taken tens of millions of cubic kilometres of water to carve such deep gorges and canyons. Practically all the atmospheric water of all the ages of Mars should have been concentrated only on Labyrinthus Noctis. Moreover, the atmosphere on Mars is too thin and the temperatures too cold. Water that came to the surface wouldn’t stay liquid, he notes: “How could a river of sufficient force and size even form?” Leone’s study could have far-reaching consequences. “If we suppose that lava formed the Noctis Labyrinthus and the Valles Marineris, then there has always been much less water on Mars than the research community has believed to date,” he says. Mars received very little rain in the past and it would not have been sufficient to erode such deep and large gorges. He adds that the shallow ocean north of the equator was probably much smaller than imagined – or hoped for; it would have existed only around the North Pole. The likelihood that life existed, or indeed still exists, on Mars is accordingly much lower. Leone can imagine that the lava tubes still in existence are possible habitats for living organisms, as they would offer protection from the powerful UV rays that pummel the Martian surface. He therefore proposes a Mars mission to explore the lava tubes. He considers it feasible to send a rover through a hole in the ceiling of a tube and search for evidence of life. “Suitable locations could be determined using my data,” he says. With his study, the Italian is swimming against the current and perhaps dismantling a dogma in the process. Most studies of the past 20 years have been concerned with the question of water on Mars and how it could have formed the canyons. Back in 1977, a researcher first posited the idea that the Valles Marineris may have been formed by lava, but the idea failed to gain traction. Leone says this was due to the tunnel vision that the red planet engenders and the prevailing mainstream research. The same story has been told for decades, with research targeted to that end, without achieving a breakthrough. Leone believes that in any case science would only benefit in considering other approaches. “I expect a spirited debate,” he says. “But my evidence is strong.” Giovanni Leone \| Eurek Alert! Global study of world's beaches shows threat to protected areas 19.07.2018 \| NASA/Goddard Space Flight Center NSF-supported researchers to present new results on hurricanes and other extreme events 19.07.2018 \| National Science Foundation A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Health and Medicine 19.07.2018 \| Earth Sciences 19.07.2018 \| Power and Electrical Engineering	<urn:uuid:8a53d6c9-cb0e-4c1e-b89f-eedc01adf7d3>	4.125	1,912	Content Listing	Science & Tech.	41.878891	95,577,438
- Full paper - Open Access Seismicity prior to the 2016 Kumamoto earthquakes © The Author(s) 2016 Received: 1 August 2016 Accepted: 29 October 2016 Published: 22 November 2016 The 2016 Kumamoto earthquakes, including a magnitude M7.3 mainshock that struck on April 16, 2016, as well as active foreshocks and aftershocks, fulfilled a section of the Futagawa–Hinagu fault zones. The zones are encompassed by the Beppu–Shimabara graben, a geological formation that runs across the middle of Kyushu, from Beppu Bay in the east to the Shimabara Peninsula in the west. This is understood as being the result of crustal deformation caused by the rifting and spreading of the Okinawa Trough, which is viewed as a continuation of the Beppu–Shimabara graben (Tada 1985). The November 14, 2015, M7.1 earthquake occurred Off Satsuma Peninsula in the Okinawa Trough. This event and the Kumamoto earthquakes are considered to be the onset that occurred under the same tectonics (Ishibashi 2016). A wide variety of approaches have been applied to earthquake prediction and forecasting. Most proposed prediction and forecasting methods rely on the concept of a diagnostic precursor, i.e., some kind of signal observable before earthquakes that indicates with high probability the location, time, and magnitude of an impending event. Precursor methods include changes in strain rates, seismic wave speeds, and electrical conductivity; variations of radon concentrations in groundwater, soil, and air; fluctuations in groundwater levels; electromagnetic variations near and above the Earth’s surface; and seismicity patterns. Despite this, the search for diagnostic precursors has not yet produced a successful short-term prediction scheme (e.g., Keilis-Borok 2002; Scholz 2002; Kanamori 2003; International Commission on Earthquake Forecasting for Civil Protection 2011). Despite such a notable lack of success, there has been a resurgence of research on earthquake predictability motivated by better monitoring networks and data on past events, new knowledge of the physics of earthquake ruptures, and a more comprehensive understanding of stress evolution and transfer. The California and international working groups, RELM (Field 2007) and CSEP (Jordan 2006), have been supporting research on earthquake predictability, conducting scientific experiments under rigorous, controlled conditions and evaluating them using accepted criteria specified in advance. These groups point to future directions of model development of earthquake prediction and forecasting as well as its testing. However, making full use of currently available resources for and a new knowledge and understanding of seismology, there needs predictability research that is not directly associated with the RELM and CSEP, but rather that addresses more general questions about the improvement of different hypotheses on earthquake generation and different concepts related to diagnostic precursor. Different methods exist to measure, map, and evaluate possible episodes before mainshocks. Examples include the b-value method (e.g., Schorlemmer and Wiemer 2005; Nanjo et al. 2012), RTL-/RTM-algorithms (e.g., Sobolev and Tyupkin 1997; Nagao et al. 2011), the Z-value method (e.g., Wiemer and Wyss 1994; Wyss et al. 2004; Katsumata 2015), and seismicity density analysis (Lippiello et al. 2012). To our knowledge, there is no standardized approach that encourages researchers to rely exclusively on a single method. Instead, multiple methods must be used to find evidence of precursory episodes. One disadvantage is that the results obtained by different methods may not be easily compared, although one may gain more confidence in impending earthquakes when using different methods. Also, additional insight may be gained because of intrinsic differences in the statistical characterization of seismic patterns. Early attempts were made by Wyss et al. (2004) who used the RTL-algorithm and Z-value methods and by Enescu and Ito (2001) who used the b-value and Z-value methods, and a fractal dimension approach. This paper reports the first results of recognizing seismic patterns as possible precursory episodes to the 2016 Kumamoto earthquakes using existing four different methods: the b-value method, two kinds of seismic quiescence evaluation methods (RTM-algorithm and Z-value), and seismicity density analysis. These methods are based on different assumptions, selection of sampling volumes, algorithms, and definitions of anomalies; thus, they are representative of a wide variety of methods that can be used to detect precursory anomalies. Before presenting further details of our study, we present a brief overview of the methods that were used. The b-value method The b-value is the slope of the Gutenberg–Richter (GR) frequency–magnitude distribution of earthquakes (Gutenberg and Richter 1944), log10 N = a − bM, where N is the cumulative number of earthquakes of M or greater, a is the earthquake productivity of a volume, and b is used to describe the relative occurrence of large and small events (i.e., a high b-value indicates a larger proportion of small earthquakes, and vice versa). Spatial and temporal changes in b are known to reflect a structural heterogeneous structure (e.g., Mogi 1962) such as strong coupling along subduction zones and a magma chamber (e.g., Tormann et al. 2015). In the laboratory and the Earth’s crust, the b-value is also known to be inversely dependent on differential stresses (Scholz 1968, 2015). In this context, measurements of spatial temporal changes in b could act as a stress meter to help image asperities, the highly stressed patches in faults where future ruptures are likely to occur (e.g., Schorlemmer and Wiemer 2005; Nanjo et al. 2012; Tormann et al. 2015). This is a type of weighted method that assesses the time, space, and the size of earthquakes, and is a modified RTL-algorithm (e.g., Sobolev and Tyupkin 1997, 1999; Huang and Nagao 2002; Huang 2004, 2006; Sobolev 2011). The RTM-algorithm measures the level of seismic activity in moving windows by counting the number of earthquakes that are weighted by their size and inversely weighted by their distances in time and space from the point of observation. A detailed description is provided by Nagao et al. (2011). A decrease in the RTM value implies a decrease in seismicity compared to the background rate around the investigated location (a seismic quiescence). A recovery stage from quiescence to the background level can be broadly considered as foreshock activation. The RTM method evaluates both seismic quiescence and the following stage of activation. In addition, the location of extreme, if it is an anomaly, can be found by performing RTM-calculations with the centers of the sampling circles at the nodes of a grid. The Z-value method The Z-mapping approach measures the difference in seismicity rate, within moving time windows, to the background rate by a standard deviation, Z (Wiemer and Wyss 1994; Wyss et al. 2004; Katsumata 2015). The purpose is to detect possible periods of anomalously low seismicity just before the mainshock near its epicenter and to evaluate the statistical significance of such quiescence compared with all other parameters that may have occurred at random times and locations. The standard deviation Z is defined as Z = (R 1 − R 2)/(S 1/n 1 + S 2/n 2)1/2, where R 1 and R 2 are the mean rates, S 1 and S 2 are the variances, and n 1 and n 2 are the number of events in the first and second periods to be compared. The larger the Z-value, the more significant the observed difference. Seismicity density analysis An increase in the number of smaller magnitude events before large earthquakes is often observed. The linear density probability of earthquakes occurring before and after events defined as mainshocks, ρ(Δr), as a function of the distance from the mainshock hypocenter, Δr, displays a symmetric behavior (Lippiello et al. 2012). This behavior indicates that the size of the area fractured during the mainshock is associated with the spatial organization of seismicity before the mainshock, because the spatial organization after the mainshock reflects the mainshock rupture area (Lippiello et al. 2012). The analysis based on Lippiello et al. (2012), hereinafter referred to as the seismicity density analysis, can be implemented to forecast the size of the mainshock. The objective of this paper is to detect such symmetric behavior for the Kumamoto earthquakes and to evaluate the possible size of the preparatory areas to the earthquakes. Our dataset is the earthquake catalog maintained by the Japan Meteorological Agency (JMA). We mainly used earthquakes since 2000, the start of modernization of the seismic networks feeding data to JMA (Obara et al. 2005). Since aftershocks add noise to both the Z-value method and the RTM-algorithm, we used a declustered catalog as a basic input for these methods. We eliminated aftershocks using the JMA standard declustering program (for details, see Appendix 1 and Fig. A1 in Additional file 1), which is classified as a link algorithm (Frolich and Davis 1990). A reliable estimate of completeness magnitude M c, above which all earthquakes are considered to be detected by a seismic network, is vital for seismicity-related studies. We paid attention to catalog completeness and performed a completeness check as a preprocessing step of individual analyses while referring to a comprehensive analysis of M c in Japan (Nanjo et al. 2010). The b-value method Characteristic precursory phenomena Area of 0.3° × 0.3° containing a part of the source zone of the Kumamoto mainshock Area of 2° × 3° between the Kumamoto and Off Satsuma Peninsula mainshocks 1.5 years for the Kumamoto mainshock (1 year for the Off Satsuma Peninsula mainshock) Area with R = 100 km between the Kumamoto and Off Satsuma Peninsula mainshocks 1.5 years for the Kumamoto mainshock (1 year for the Off Satsuma Peninsula mainshock) Seismicity density analysis Area with Δr = 8–40 km containing a part of the source zone of the Kumamoto mainshock 3 years or longer for the Kumamoto mainshock A temporal variation of RTM at an almost equidistant point from the 2015 Off Satsuma Peninsula earthquake and the 2016 Kumamoto mainshock showed a significant decrease prior to the occurrence of both (Fig. 2a, see also Table A1 in Additional file 1). A deviation from the background level started at 2014.8 years for mid-October 2014, and the strongest deviation in 2015.8 years for mid-October 2015 was about −20. During the critical period, the R, T, and M functions attained values of about −2.5 to −3.0. During a recovery stage from the quiescence to the background level, the 2015 Off Satsuma Peninsula earthquake and the 2016 Kumamoto mainshock occurred. This property is similar to that documented by other studies that used the RTL-/RTM-algorithm (e.g., Sobolev and Tyupkin 1997, 1999; Huang and Nagao 2002; Huang 2004, 2006; Nagao et al. 2011; Sobolev 2011). Since the RTM-algorithm is statistical and nonlinear, we were unable to identify which of earthquakes contributed to the recovery stage; this topic is beyond the scope of our work in this paper. A map view of RTM values on October 1, 2015, reveals a highly significant change between the 2015 Off Satsuma Peninsula earthquake and the 2016 M7.3 Kumamoto mainshock indicated by stars in Fig. 2b, in which the parameter set was the same as that for Fig. 2a. The characteristic dimension of seismic quiescence in an approximately 2° × 3° area is 200–300 km. We created a map of RTM values using the same parameter set as that for Fig. 2b except that a higher threshold (M min = 2.4) was applied. The position of the anomalous zone is not very sensitive (see panel E of Fig. A10 in Additional file 1). We also used three different sets of parameters with M min = 2 and created RTM maps to support a more robust anomalous pattern (see panels A–C of Fig. A10 and Table A1 in Additional file 1). To strengthen the related conclusion, it would be better to conduct a reliability analysis of the revealed anomalies in detail, e.g., following the approach taken by Huang (2006). However, the main purpose of this paper was to provide the first results on how to recognize possible precursory episodes to the 2016 Kumamoto earthquakes, as described in “Introduction.” Thus, we presented essential parts of the reliability analysis such as completeness check, quality test of a declustered catalog, and some levels of a parameter survey. For a full justification of the present conclusion, further detailed investigations involving the robustness of the temporal and spatial pattern should be conducted. Our results do not indicate that the observed seismic quiescence precedes either of the mainshocks. The 2015 Off Satsuma Peninsula earthquake and the 2016 Kumamoto earthquakes are considered to be the onset that occurred at a section along the tectonic line from the Okinawa Trough through the Beppu–Shimabara graben (Ishibashi 2016). Our results, combined with these tectonics, indicate that a series of earthquakes along the tectonic line was preceded by seismic quiescence. These results are summarized in Table 1. The Z-value method Seismicity density analysis Before assuming the approach based on Lippiello et al. (2012) for Japan, a complete check of the JMA catalog since 1998 was performed as a preprocessing step. We decided to use inland earthquakes only and set a lower threshold at M min = 1. The previous Z-value and RTM approaches were applied to data including both inland and offshore earthquakes (Figs. 2, 3). M c of the JMA catalog was generally lower in inland regions than in offshore regions (Nanjo et al. 2010), which explains why M min = 1 for this seismicity density analysis is different from M min = 2 and 2.4 for the Z-value and RTM approaches. We next compared the size of spatial organization before and after mainshocks with the size of asperity (Fig. 4). As a representative of the former size, we detected the deviation point from a scaling relation ρ(Δr) ~ Δr −η (the inset in Fig. 4). This deviation point is defined as the characteristic distance Δr c, below which the scaling is no longer valid, due to large variance of seismicity density or low seismicity density at very short distances to the mainshock hypocenter, above a location uncertainty of ~100 m in the JMA catalog. We created a plot of Δr c versus m for 3 ≤ m < 6 in Fig. 4. The latter size was based on the scaling between asperity area S a and m (Somerville et al. 2015). Assuming a circular asperity S a = πl a 2 where l a is the characteristic asperity radius, we included the l a − m relation in Fig. 4. Data (gray points) show a positive correlation with large scatter, and the Δr c − m correlation appears to be similar to the l a − m relation. To support this idea, data from the Δr c − m correlation need to be increased. Discussion and conclusions Although long-term probabilistic seismic hazard assessment can be made in Japan (e.g., National Seismic Hazard Maps for Japan) and other seismically active regions, it is generally accepted that immediate local precursory phenomena are not seen ubiquitously. In order to test the hypothesis of a local precursor for a fault system, the Parkfield Earthquake Predictability Experiment was initiated in 1985. The expected Parkfield earthquake occurred beneath the heavily instrumented region on September 28, 2004. No local precursory changes were observed (Lindh 2005). In the absence of local precursory signals, the next question is whether broader anomalies develop and in particular whether there is anomalous seismicity. Before attempting to identify precursory phenomena, a fundamental question is whether there are different forecast methods applicable to seismicity in a region of interest, in particular in Japan. This is the question that we addressed in this paper. We decided to use the b-value method, the RTM-algorithm, seismicity density analysis, and the Z-value method and applied them to seismicity before the Kumamoto earthquakes. Our study is the first report on this theme after completing the modernization of seismic monitoring in Japan. Before this, an early attempt was made by Enescu and Ito (2001), who used the b-value method, the Z-value method, and fractal dimensions to discover premonitory quiescence followed by activation of seismicity about 2 years before the occurrence of the 1995 M7.2 Kobe earthquake. These authors conducted their study before the completion of the modernization of seismic monitoring in Japan and used the local network data of Kyoto University, besides the JMA catalog data, to ensure a relatively low and stable magnitude of completeness during the whole analyzed time period. The combination of multiple methods may enhance the reliability of the revealed anomalies when compared to the reliability of a single method. We performed some comprehensive comparisons of the results from each method to support this claim. The properties of precursory episodes are summarized in Table 1. Estimates of the duration and spatial extent contain uncertainties, which depend on the approaches taken in the analysis. The durations were almost identical in both the RTM-algorithm and the Z-value method. In these methods, the resulting maximum expression of the anomalies did not coincide with the epicenters of the Kumamoto mainshock, nor of the Off Satsuma Peninsula mainshock. Furthermore, both methods did not identify the same locations for the anomalous maximum. Wyss et al. (2004) indicated a reason for the difference between methods in pinpointing the location of an anomaly. The weighting of results based on the size of the earthquakes, which is only done in the RTM method but not in the Z-value method, results in some differences in the estimated significance in most samples. Therefore, the maximum expression of the anomaly was not observed at exactly the same locations. The reason for the maximum expression of anomaly not pointing to the epicenters may be due to the fact that the onset of both earthquakes may have been at a segment along the tectonic line from the Okinawa Trough (Ishibashi 2016). The large area of the anomaly may reflect the nature of the process leading up to the phenomenon in the regional tectonic condition. Nonetheless, the two methods based on different assumptions, different algorithms, and different definitions of anomaly, arrived at very similar results. This strongly suggests that the observed anomalies are real, and can be determined with considerable reliability. In contrast to these two methods, the b-value method and seismicity density analysis seem to have narrower spatial extents (Table 1). The close match found in spatial extent between the different approaches implies that asperities (highly stressed patches) may act as an indicator of the preparation process to an impending earthquake. A duration of 3 years or longer from the seismicity density analysis (Table 1) is longer than that revealed by both the RTM-algorithm and the Z-value method. The precursory duration from application of the b-value method to analyzed data for the past 16 years is unknown. The timing of the earthquake remains uncertain from low b-values and spatial organization prior to the Kumamoto earthquakes. This is consistent with another observation of active faults in which the heterogeneous pattern of b-values at Parkfield was, to a high degree, stationary for the past 35 years and the 2004 M6 earthquake eventually occurred at a zone of low b-values (Schorlemmer and Wiemer 2005). A decrease in b tracking stress buildup, as expected from a laboratory experiment (Scholz 1968), may not be observable for the decade-scale observation of active faults in Japan and California, because it is too short to observe such a decrease in b. Instead, the stationary nature of b-values, as observed in Fig. 1, is reasonable. The mechanism of stress buildup within the fault zones is uncertain, but one hypothesis is that a steady slip of the deeper continuation of faults that does not produce earthquakes, but still involves motions across the fault, forces the upper crust around the faults to deform and thus concentrate stress. This is still difficult to measure directly. Overall, our findings indicate that the methods we adopted do not allow the Kumamoto earthquakes to be predicted exactly. The spatial extent of precursory patterns that were detected differed from one method to another and ranged from local scales (equivalent to an asperity dimension) to regional scales (typically, 100–200 km). The Kumamoto earthquakes were preceded by periods of pronounced anomalies, which lasted yearly scales (1.5 years) or longer (>3 years). Given the widely different scales of anomalies in time and space, a combination of multiple methods was able to detect different signals prior to the Kumamoto earthquakes. This strongly suggests a great potential to reduce the hazard at possible future sites of earthquakes relative to long-term seismic hazard assessment. We also found that the seismic quiescence in a regional-scale area, detected by using the RTM-algorithm and the Z-value method, was a common precursor to the 2016 Kumamoto earthquakes and 2015 Off Satsuma Peninsula earthquake that occurred 5 months before the 2016 Kumamoto earthquakes. The precursory durations of 1 year to the 2015 Off Satsuma Peninsula earthquake were almost identical in both approaches. The result allows us to interpret both events as the onset that occurred at a section along the tectonic line from the Okinawa Trough through the Beppu–Shimabara graben (Ishibashi 2016). All the authors performed numerical simulations, analyzed data, and prepared the figures, in particular b-value method (KZN, JI), RTM-algorithm (TN), Z-value method (KZN), seismicity density analysis (YO, ST, HN, TO, RT, MK), and application of declustering programs (KZN, NF, TN). KZN and TN helped to draft the manuscript. KZN wrote the final manuscript. All authors read and approved the final manuscript. The authors thank the editor (M. Hashimoto) and two anonymous referees for their useful comments. This study was partly supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, under its Earthquake and Volcano Hazards Observation and Research Program (KZN, JI, YO, MK, TN) and a Grant-in-Aid for Scientific Research (C), No. 26350483, 2014–2017 (MK), and the Collaboration Research Program of IDEAS, Chubu University IDEAS201614 (JI). The authors declare that they have no competing interests. Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. - Enescu B, Ito K (2001) Some premonitory phenomena of the 1995 Hyogo-Ken Nanbu (Kobe) earthquake: seismicity, b-value and fractal dimension. Tectonophysics 338(3–4):297–314. doi:10.1016/S0040-1951(01)00085-3 View ArticleGoogle Scholar - Felzer KR, Brodsky EE (2006) Decay of aftershock density with distance indicates triggering by dynamic stress. Nature 441:735–738. doi:10.1038/nature04799 View ArticleGoogle Scholar - Field EH (2007) Overview of the working group for the development of regional earthquake likelihood models (RELM). Seismol Res Lett 78:7–16. doi:10.1785/gssrl.78.1.7 View ArticleGoogle Scholar - Frohlich C, Davis SD (1990) Single-link cluster analysis as a method to evaluate spatial and temporal properties of earthquake catalogues. Geophys J Int 100(1):19–32. doi:10.1111/j.1365-246X.1990.tb04564.x View ArticleGoogle Scholar - Gutenberg B, Richter CF (1944) Frequency of earthquakes in California. Bull Seismol Soc Am 34(4):185–188Google Scholar - Huang Q (2004) Seismicity pattern changes prior to large earthquakes: an approach of the RTL algorithm. Terr Atmos Ocean Sci 15(3):469–491Google Scholar - Huang Q (2006) Search for reliable precursors: a case study of the seismic quiescence of the 2000 western Tottori prefecture earthquake. J Geophys Res 111:B04301. doi:10.1029/2005JB003982 Google Scholar - Huang Q, Nagao T (2002) Seismic quiescence before the 2000 M = 7.3 Tottori earthquake. Geophys. Res. Lett. 29(12):19-1–19-4. doi:10.1029/2001GL013835 View ArticleGoogle Scholar - International Commission on Earthquake Forecasting for Civil Protection (2011) Operational earthquake forecasting. State of knowledge and guidelines for utilization. Ann Geophys. doi:10.4401/ag-5350 Google Scholar - Ishibashi K (2016) The 2016 Kumamoto earthquakes are not exceptional. Kagau (Science) 86(6):532–540 (In Japanese) Google Scholar - Jordan T (2006) Earthquake predictability, brick by brick. Seismol Res Lett 77:3–6View ArticleGoogle Scholar - Kanamori H (2003) Earthquake prediction: An overview. In: Lee WHK, Kanamori H, Jennings PC, Kisslinger C (eds) International handbook of earthquake & engineering seismology. Academic Press, Amsterdam, pp 1205–1216View ArticleGoogle Scholar - Katsumata K (2015) A long-term seismic quiescence before the 2004 Sumatra (Mw 9.1) earthquake. Bull Seismol Soc Am 105(1):167–176. doi:10.1785/0120140116 View ArticleGoogle Scholar - Keilis-Borok V (2002) Earthquake predictions: state-of-the-art and emerging possibilities. Ann Rev Earth Planet Sci 30:1–33. doi:10.1146/annurev.earth.30.100301.083856 View ArticleGoogle Scholar - Lindh AG (2005) Success and failure at Parkfield. Bull Seismol Soc Am 76(1):3–6. doi:10.1785/gssrl.76.1.3 Google Scholar - Lippiello E, Marzocchi W, de Arcangelis L, Godano C (2012) Spatial organization of foreshocks as a tool to forecast large earthquakes. Sci Rep 2:846. doi:10.1038/srep00846 View ArticleGoogle Scholar - Mogi K (1962) Magnitude-frequency relation for elastic shocks accompanying fractures of various materials and some related problems in earthquakes. Bull Earthq Res Inst 40:831–853Google Scholar - Nagao T, Takeuchi A, Nakamura K (2011) A new algorithm for the detection of seismic quiescence: introduction of the RTM algorithm, a modified RTL algorithm. Earth Planets Space 63:315–324. doi:10.5047/eps.2010.12.007 View ArticleGoogle Scholar - Nanjo KZ, Ishibe T, Tsuruoka H, Schorlemmer D, Ishigaki Y, Hirata N (2010) Analysis of the completeness magnitude and seismic network coverage of Japan. Bull Seismol Soc Am 100(6):3261–3268. doi:10.1785/0120100077 View ArticleGoogle Scholar - Nanjo KZ, Hirata N, Obara K, Kasahara K (2012) Decade-scale decrease in b value prior to the M9-class 2011 Tohoku and 2004 Sumatra quakes. Geophys Res Lett 39:L20304. doi:10.1029/2012GL052997 View ArticleGoogle Scholar - National Research Institute for Earth Science and Disaster Resilience (2016) http://www.kyoshin.bosai.go.jp/kyoshin/topics/Kumamoto_20160416/inversion/. Access 20 Sept 2016 - Obara K, Kasahara K, Hori S, Okada Y (2005) A densely distributed high-sensitivity seismograph network in Japan: Hi-net by National Research Institute for Earth Science and Disaster Prevention. Rev Sci Instrum 76:021301. doi:10.1063/1.1854197 View ArticleGoogle Scholar - Richards-Dinger K, Stein RS, Toda S (2010) Decay of aftershock density with distance does not indicate triggering by dynamic stress. Nature 467:583–586. doi:10.1038/nature09402 View ArticleGoogle Scholar - Roberts NS, Bell AF, Main IG (2015) Are volcanic seismic b-values high, and if so when? J Volcanol Geotherm Res 308:127–141. doi:10.1016/j.jvolgeores.2015.10.021 View ArticleGoogle Scholar - Scholz CH (1968) The frequency-magnitude relation of microfracturing in rock and its relation to earthquakes. Bull Seismol Soc Am 58(1):399–415Google Scholar - Scholz CH (2002) The mechanics of earthquakes & faulting, 2nd edn. Cambridge University Press, CambridgeView ArticleGoogle Scholar - Scholz CH (2015) On the stress dependence of the earthquake b value. Geophys Res Lett 42:1399–1402. doi:10.1002/2014GL062863 View ArticleGoogle Scholar - Schorlemmer D, Wiemer S (2005) Microseismicity data forecast rupture area. Nature 434:1086. doi:10.1038/4341086a View ArticleGoogle Scholar - Shi Y, Bolt BA (1982) The standard error of the magnitude-frequency b-value. Bull Seismol Soc Am 72:1677–1687Google Scholar - Sobolev GA (2011) Seismicity dynamics and earthquake predictability. Nat Hazards Earth Syst Sci 11:445–458. doi:10.5194/nhess-11-445-2011 View ArticleGoogle Scholar - Sobolev GA, Tyupkin YS (1997) Low-seismicity precursors of large earthquakes in Kamchatka. Volcanol Seismol 18:433–446Google Scholar - Sobolev GA, Tyupkin YS (1999) Precursory phases, seismicity precursors, and earthquake prediction in Kamchatka. Volcanol Seismol 20:615–627Google Scholar - Sommerville P, Skarlatoudis A, Thio HK (2015) Source scaling relations of subduction earthquakes for strong ground motion and tsunami prediction. http://earthquake.usgs.gov/research/external/reports/G13AP00028.pdf. Accessed 20 Sept 2016 - Tada T (1985) Spreading of the Okinawa Trough and its relation to the crustal deformation in the Kyushu (2). Zisin 38(1):1–12 (In Japanese with English abstract) Google Scholar - Tormann T, Enescu B, Woessner J, Wiemer S (2015) Randomness of megathrust earthquakes implied by rapid stress recovery after the Japan earthquake. Nat Geosci 8:152–158. doi:10.1038/ngeo2343 View ArticleGoogle Scholar - Wiemer S, Wyss M (1994) Seismic quiescence before the Landers (M = 7.5) and Big Bear (M = 6.5), earthquakes. Bull Seismol Soc Am 84(3):900–916Google Scholar - Woessner J, Wiemer S (2005) Assessing the quality of earthquake catalogues: Estimating the magnitude of completeness and its uncertainty. Bull Seismol Soc Am 95:684–698. doi:10.1785/0120040007 View ArticleGoogle Scholar - Wyss M, Sobolev G, Clippard JD (2004) Seismic quiescence precursors to two M7 earthquakes on Sakhalin Island, measured by two methods. Earth Planets Space 56(8):725–740. doi:10.1186/BF03353081 View ArticleGoogle Scholar - Yagi Y, Okuwaki R, Enescu B, Kasahara A, Miyakawa A, Otsubo M (2016) Rupture process of the 2016 Kumamoto earthquake in relation to the thermal structure around Aso volcano. Earth Planets Space 68:118. doi:10.1186/s40623-016-0492-3 View ArticleGoogle Scholar	<urn:uuid:ba0ad2a4-8447-4cd2-96ef-a18ab0b11ca5>	2.609375	7,221	Truncated	Science & Tech.	49.739761	95,577,449
Genome of Strawberry Revealed News Nov 01, 2016 NRGene is the first ever to assemble the complex genome of a commercially grown strawberry. Most plant, animal, and human genomes are diploid - containing two variants from each gene. The strawberry genome contains eight nearly identical copies of each gene, making the accurate phasing of each something that has never been done before – until NRGene’s DeNovoMAGICTM 3.0. The octoploid, heterozygous strawberry genome was assembled using reads produced on Illumina sequencing technology and assembled by NRGene’s cloud-based DeNovoMAGICTM 3.0 software package in only two weeks. “It’s exciting to see how NRGene’s analysis, combined with data from Illumina sequencers, can be used to quickly and affordably assemble complex genomes, like that of the strawberry,” said Ryan Rapp, Associate Director, Agrigenomics for Illumina. “We hope that this technology will make genomics accessible to agricultural researchers worldwide, helping to improve the food supply to make it more sustainable and efficient.” NRGene’s DeNovoMAGICTM 3.0 delivers complete, highly accurate genome assemblies in the form of long, phased sequences using Illumina-based reads. As more genomes are generated, NRGene’s PanMAGICTM is used to compare the complete genome sequences of multiple individual samples to capture the broad genomic diversity, better pinpointing positive traits across all varieties. “With the data from NRGene, strawberry breeders will be able to accelerate the release of better performing strawberry varieties, creating hardier, more disease-resistant varieties with longer shelf lives,” says Sachiko Isobe, head of the plant genomics and genetics laboratory at Japan’s Kazusa DNA Research Institute. NRGene has delivered the first bread wheat, Emmer wheat, and durum wheat genomes; dozens of new maize, soybean, cotton, and canola genomes; and is delivering more accurate versions of previously mapped genomes built on older, more inefficient technologies. “The strawberry assembly demonstrates that even the most complex genomes can be mapped quickly and accurately,” says Gil Ronen, CEO of NRGene. “The ultimate value in our technology is that it can be deployed to analyze and assemble any genome across all species.” The project was done in cooperation with Japan’s Kazusa DNA Research Institute and supported in part by Japan’s Ministry of Agriculture, Forestry and Fisheries. Analytical Tool Predicts Disease-Causing GenesNews Predicting genes that can cause disease due to the production of truncated or altered proteins that take on a new or different function, rather than those that lose their function, is now possible thanks to an international team of researchers that has developed a new analytical tool to effectively and efficiently predict such candidate genes. Single Gene Change in Gut Bacteria Alters Host MetabolismNews Scientists have found that deleting a single gene in a particular strain of gut bacteria causes changes in metabolism and reduced weight gain in mice. The research provides an important step towards understanding how the microbiome – the bacteria that live in our body – affects metabolism.READ MORE Gotta Sample 'Em All! Underwater Pokéball Captures Ocean LifeNews A new device developed by Wyss Institute reseachers safely traps delicate sea creatures inside a folding polyhedral enclosure and lets them go without harm using a novel, origami-inspired design. The ultimate aim is to allow the sea creatures to be (gently) analyzed in high detail.READ MORE	<urn:uuid:76c49d4e-0a8d-40ee-94a9-e30f4f17934b>	3.03125	749	Content Listing	Science & Tech.	15.647112	95,577,470
1.3 Different ways of "visualizing" a charge: towards the concept of FIELD To introduce the concept of field we shall first consider different ways of visualizing a charge. Our primary aim is to show that the idea of a perturbation extending all across the space due to the presence of a charge is of the same importance as that of the charge considered as a particle. That perturbation is the field.	<urn:uuid:9b9bcb69-ac4b-45ce-9777-ff8abf370d35>	3.0625	92	Tutorial	Science & Tech.	52.265	95,577,472
Computer modeling driven by data gleaned from Mount Lassen basalt opens window on water's role deep in the Earth and on the surface University of Oregon geologists have tapped water in surface rocks to show how magma forms deep underground and produces explosive volcanoes in the Cascade Range. "Water is a key player," says Paul J. Wallace, a professor in the UO's Department of Geological Sciences and coauthor of a paper in the May issue of Nature Geoscience. "It's important not just for understanding how you make magma and volcanoes, but also because the big volcanoes that we have in the Cascades -- like Mount Lassen and Mount St. Helens -- tend to erupt explosively, in part because they have lots of water." A five-member team, led by UO doctoral student Kristina J. Walowski, methodically examined water and other elements contained in olivine-rich basalt samples that were gathered from cinder cone volcanoes that surround Lassen Peak in Northern California, at the southern edge of the Cascade chain. The discovery helps solve a puzzle about plate tectonics and the Earth's deep water cycle beneath the Pacific Ring of Fire, which scientists began studying in the 1960s to understand the region's propensity for big earthquakes and explosive volcanoes. The ring stretches from New Zealand, along the eastern edge of Asia, north across the Aleutian Islands of Alaska and south along the coast of North and South America. It contains more than 75 percent of the planet's volcanoes. To understand how water affects subduction of the oceanic plate, in which layers of different rock types sink into the mantle, the UO team studied hydrogen isotopes in water contained in tiny blobs of glass trapped in olivine crystals in basalt. To do so, the team used equipment in Wallace's lab, CAMCOR, the Carnegie Institution in Washington, D.C., and a lab at Oregon State University. CAMCOR is UO's Advanced Materials Characterization in Oregon, a high-tech extension service located in the underground Lorry I. Lokey Laboratories. Next, the team fed data gained from the rocks into a complex computer model developed by co-author Ikudo Wada, then of Japan's Tohoku University. She has since joined the University of Minnesota. That combination opened a window on how rising temperatures during subduction drive water out of different parts of the subducted oceanic crust, Walowski said. Water migrates upwards and causes the top of the subducted oceanic crust to melt, producing magma beneath the Cascade volcanoes. The key part of the study, Wallace said, involved hydrogen isotopes. "Most of the hydrogen in water contains a single proton," he said. "But there's also a heavy isotope, deuterium, which has a neutron in addition to the proton. It is important to measure the ratio of the two isotopes. We use this ratio as a thermometer, or probe, to study what's happening deep inside the earth." "Melting of the subducting oceanic crust and the mantle rock above it would not be possible without the addition of water," Walowski said. "Once the melts reach the surface, the water can directly affect the explosiveness of magma. However, evidence for this information is lost to the atmosphere during violent eruptions." The National Science Foundation (grant EAR-1119224) and Carnegie Institution supported the research. Other coauthors were E.H. Hauri of the Carnegie Institution and M.A. Clynne of the U.S. Geological Survey. Note: The UO is equipped with an on-campus television studio with a point-of-origin Vyvx connection, which provides broadcast-quality video to networks via a fiber optic network. In addition, there is video access to satellite uplink, and audio access to an ISDN codec for broadcast-quality radio interviews. About Walowski: http://geology. About Wallace: http://geology. Department of Geological Sciences: http://geology. Jim Barlow \| EurekAlert! Abrupt cloud clearing events over southeast Atlantic Ocean are new piece in climate puzzle 23.07.2018 \| University of Kansas Global study of world's beaches shows threat to protected areas 19.07.2018 \| NASA/Goddard Space Flight Center A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 23.07.2018 \| Science Education 23.07.2018 \| Health and Medicine 23.07.2018 \| Life Sciences	<urn:uuid:9e77a055-6374-44cb-9434-b2666c27afc3>	3.84375	1,433	Content Listing	Science & Tech.	41.730618	95,577,480
General Relativity We start by examining the basic physics of black holes, which fundamentally means understanding gravity. CfE Advanced Hher Physics. Rotational Motion & Astrophysics Homework. 5. General Relativity. 1. A satellite is in orbit around the Earth at an altitude of. Geocentricity critics refuse to do their homework In section B, the challenging section, you will be asked to answer 2 out of 4 questions for a total mark of 50. The great irony of Dr. Nieto's essay is his complete reliance on Einstein's General Theory of Relativity. The irony obtains from the fact that general relativity. Ph 236 General Relativity - Tapir - Caltech In the second part of the course I will introduce the Einstein equations, both in vacuum and with various matter fields. The course will serve as an introduction to general relativity. 11/28/12 Note skipped 1 week due to Thanksgiving; Homework 8 due 12/06/12 1/2 homework. PHYS 631, Spring 2015 General Relativity The lecture will provide an introduction to General Relativity. A Short Course in General Relativity, 2nd Edition, Bernard Schutz, 2009. I will give you homework every week to week and a half corresponding to about a. A general relativity workbook - Pomona College The present course deliberately sidesteps several of these mathematical foundations and focuses on physical concepts. The textbook for the course uses the same approach. Homework Problems 9. General Relativity in a Nutshell 11. 2. REVIEW OF SPECIAL RELATIVITY 13. Concept Summary 14. Box 2.1 Overlapping IRFs Move. General Relativity - Homework In section A, the basic section, you will be asked to answer ALL questions for a total mark of 50. ASTR-4240 Gravitation & Cosmology. PHYS-4240 General Relativity. Spring, 2016. Homework Assnments. Homework is due in class on the. Physics 514 General Relativity Winter 2016 - McGill Physics As well as being the ultimate laboratory for studying the nature of space and time, they drive some of the most energetic and extreme phenomena known to astronomers (with quasars and gamma-ray bursts being just a couple of examples.) Astronomy 398B is an introduction to the physics and astrophysics of black holes. Physics 514 General Relativity Winter 2016. Homework assnments will include problem sets as well as longer, Mathematica-based computational projects. General relativity homework: Rating: 93 / 100 Overall: 95 Rates	<urn:uuid:29554c19-1ae3-4ddf-a4cf-0902caf9ecef>	3.34375	530	Content Listing	Science & Tech.	44.728434	95,577,525
This article needs additional citations for verification. (April 2013) (Learn how and when to remove this template message) TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The "ton of TNT" is a unit of energy defined by that convention to be 4.184 gigajoules, which is the approximate energy released in the detonation of a metric ton (1,000 kilograms or one megagram) of TNT. In other words, for each gram of TNT exploded, 4,184 joules of energy are released. This convention intends to compare the destructiveness of an event with that of traditional explosive materials, of which TNT is a typical example, although other conventional explosives such as dynamite contain more energy. Kiloton and megaton The kiloton and megaton of TNT have traditionally been used to describe the energy output, and hence the destructive power, of a nuclear weapon. The TNT equivalent appears in various nuclear weapon control treaties, and has been used to characterize the energy released in such other highly destructive events as an asteroid impact. Historical derivation of the value A gram of TNT releases 2673–6702 J (joules) upon explosion. The energy liberated by one gram of TNT was arbitrarily defined as a matter of convention to be 4184 J, which is exactly one kilocalorie. An explosive's energy is normally expressed as the thermodynamic work produced by its detonation, which for TNT has been accurately measured as 4686 J/g from a large sample of air blast experiments, and theoretically calculated to be 4853 J/g. A kiloton of TNT can be visualized as a cube of TNT 8.46 metres (27.8 ft) on a side. \|Grams TNT\|\|Symbol\|\|Tons TNT\|\|Symbol\|\|Energy [Joules]\|\|Energy [Wh]\|\|Corresponding mass loss\| \|gram of TNT\|\|g\|\|microton of TNT\|\|μt\|\|4.184×103 J or 4.184 kilojoules\|\|1.163 Wh\|\|46.55 pg\| \|kilogram of TNT\|\|kg\|\|milliton of TNT\|\|mt\|\|4.184×106 J or 4.184 megajoules\|\|1.163 kWh\|\|46.55 ng\| \|megagram of TNT\|\|Mg\|\|ton of TNT\|\|t\|\|4.184×109 J or 4.184 gigajoules\|\|1.163 MWh\|\|46.55 μg\| \|gigagram of TNT\|\|Gg\|\|kiloton of TNT\|\|kt\|\|4.184×1012 J or 4.184 terajoules\|\|1.163 GWh\|\|46.55 mg\| \|teragram of TNT\|\|Tg\|\|megaton of TNT\|\|Mt\|\|4.184×1015 J or 4.184 petajoules\|\|1.163 TWh\|\|46.55 g\| \|petagram of TNT\|\|Pg\|\|gigaton of TNT\|\|Gt\|\|4.184×1018 J or 4.184 exajoules\|\|1.163 PWh\|\|46.55 kg\| Conversion to other units 1 ton TNT equivalent is approximately: - 1.0×109 calories - 4.184×109 joules - 3.96831×106 British thermal units - 3.08802×109 foot pounds - 1.162×103 kilowatt hours \|Megatons of TNT\|\|Energy [Wh]\|\|Description\| \|×10−12 (i.e. 1 gram of TNT) 1\|\|1.162 Wh\|\|≈ 1 food Calorie (large calorie), which is the approximate amount of energy needed to raise the temperature of one kilogram of water by one degree Celsius at a pressure of one atmosphere.\| \|×10−9 (i.e. 1 kilogram of TNT) 1\|\|1.162 kWh\|\|Under controlled conditions one kilogram of TNT can destroy (or even obliterate) a small vehicle.\| \|×10−8 1\|\|11.62 kWh\|\|The approximate radiant heat energy released during 3-phase, 600 V, 100 kA arcing fault in a 0.5 m × 0.5 m × 0.5 m (20 in × 20 in × 20 in) compartment within a 1-second period.[further explanation needed]\| \|×10−8 1.2\|\|13.94 kWh\|\|Amount of TNT used (12 kg) in Coptic church explosion in Cairo, Egypt on December 11, 2016 that left 25 dead\| \|×10−6 (i.e. 1 ton of TNT) – 1×10−6 44\|\|1.16–51.14 MWh\|\|Conventional bombs yield from less than one ton to FOAB's 44 tons. The yield of a Tomahawk cruise missile is equivalent to 500 kg of TNT, or approximately 0.5 tons.\| \|×10−6 1.9\|\|2.90 MWh\|\|The television show MythBusters used 2.5 tons of ANFO to make "homemade" diamonds.\| \|×10−4 5\|\|581 MWh\|\|A real 0.5-kilotonne-of-TNT (2.1 TJ) charge at Operation Sailor Hat. If the charge were a full sphere, it would be 1 kilotonne of TNT (4.2 TJ).\| \|×10−3 (1 kiloton of TNT) – 1×10−3 2\|\|1.16–2.32 GWh\|\|Estimated yield of the Oppau explosion that killed more than 500 at a German fertilizer factory in 1921.\| \|×10−3 2.3\|\|2.67 GWh\|\|Amount of solar energy falling on 4,000 m2 (1 acre) of land in a year is 9.5 TJ (2,650 MWh) (an average over the Earth's surface).\| \|×10−3 3\|\|3.49 GWh\|\|The Halifax Explosion in 1917 was the accidental detonation of 3,000 tons of TNT.\| \|×10−3 4\|\|9.3 GWh\|\|Minor Scale, a 1985 United States conventional explosion, using 4,744 tons of ANFO explosive to provide a scaled equivalent airblast of an eight kiloton (33.44 TJ) nuclear device, is believed to be the largest planned detonation of conventional explosives in history.\| \|×10−2 – 1.5×10−2 2\|\|17.4–23.2 GWh\|\|The Little Boy atomic bomb dropped on Hiroshima on August 6, 1945, exploded with an energy of about 15 kilotons of TNT (63 TJ), and the Fat Man atomic bomb dropped on Nagasaki on August 9, 1945, exploded with an energy of about 20 kilotons of TNT (84 TJ). The modern nuclear weapons in the United States arsenal range in yield from 0.3 kt (1.3 TJ) to 1.2 Mt (5.0 PJ) equivalent, for the B83 strategic bomb.\| \|1\|\|1.16 TWh\|\|The energy contained in one megaton of TNT (4.2 PJ) is enough to power the average American household for 103,000 years. The 30 Mt (130 PJ) estimated upper limit blast power of the Tunguska event could power the same average home for more than 3,100,000 years. The energy of that blast could power the entire United States for 3.27 days.\| \|3\|\|3.5 TWh\|\|The total energy of all explosives used in World War II, including the Hiroshima and Nagasaki atom bombs, is estimated to have been three megatons of TNT.\| \|8.6\|\|10 TWh\|\|The energy released by a typical tropical cyclone in one minute, primarily from water condensation. Winds constitute 0.25% of that energy.\| \|21.5\|\|25 TWh\|\|The complete conversion of 1 kg of matter into pure energy would yield the theoretical maximum (E = mc2) of 89.8 petajoules, which is equivalent to 21.5 megatons of TNT. No such method of total conversion as combining 500 grams of matter with 500 grams of antimatter has yet been achieved. In the event of proton–antiproton annihilation, approximately 50% of the released energy will escape in the form of neutrinos, which are almost undetectable. Electron–positron annihilation events emit their energy entirely as gamma rays.\| \|24\|\|28 TWh\|\|Approximate total yield of the 1980 eruption of Mount St. Helens.\| \|25, 50, 100\|\|29 TWh, 58 TWh, 116 TWh\|\|During the Cold War, the United States developed hydrogen bombs with maximum theoretical yields of 25 megatons of TNT (100 PJ). The Soviet Union developed a prototype weapon, nicknamed the Tsar Bomba, which was tested at 50 Mt (210 PJ), but had a maximum theoretical yield of 100 Mt (420 PJ). The effective destructive potential of such a weapon varies greatly, depending on such conditions as the altitude at which it is detonated, the characteristics of the target, the terrain, and the physical landscape upon which it is detonated.\| \|26.3\|\|30.6 TWh\|\|Megathrust earthquakes 2004 Indian Ocean earthquake released record ME surface rupture energy, or potential for damage at 26.3 megatons of TNT (110 PJ).\| \|200\|\|232 TWh\|\|The total energy released by the eruption of Mt. Krakatoa in Indonesia in 1883.\| \|540\|\|628 TWh\|\|The total energy produced worldwide by all nuclear testing and combat combined, from the 1940s till now[when?] is about 540 megatons.\| \|1,460\|\|1.69 PWh\|\|The total global nuclear arsenal is about 15,000 nuclear warheads with a destructive capacity of around 1460 megatons or 1.460 gigatons (1,460 million tons) of TNT.\| \|62,500\|\|73 PWh\|\|The total solar energy received by Earth per minute is 440 exajoules.\| \|875,000\|\|1,000 PWh\|\|Approximate yield of the last eruption of the Yellowstone supervolcano.\| \|6,000,000 = ×106 6\|\|6,973 PWh\|\|The estimated energy at impact when the largest fragment of Comet Shoemaker–Levy 9 struck Jupiter is equivalent to 6 million megatons (6 trillion tons) of TNT.\| \|×106 9.32\|\|10,831 PWh\|\|The energy released in the 2011 Tōhoku earthquake and tsunami was over 200,000 times the surface energy and was calculated by the USGS at ×1022 joules, 3.9 slightly less than the 2004 Indian Ocean quake. This is equivalent to 9,320 gigatons of TNT, or approximately 600 million times the energy of the Hiroshima bomb.\| \|×106 9.56\|\|11,110 PWh\|\|Megathrust earthquakes record huge MW values, or total energy released. The 2004 Indian Ocean earthquake released 9,560 gigatons TNT equivalent.\| \|×108 1\|\|116,222 PWh\|\|The approximate energy released when the Chicxulub impact caused the mass extinction 66 million years ago was estimated to be equal to 100 teratons (i.e. 100 exagrams or approximately 220.462 quadrillion pounds) of TNT. That is roughly 8 billion times stronger than each of the bombs that hit Hiroshima and Nagasaki and the most energetic event on the history of Earth for hundreds of millions of years, far more powerful than any volcanic eruption, earthquake or firestorm. Such an explosion annihilated everything within a thousand miles of the impact in a split second. Such energy is equivalent to that needed to power the whole Earth for several centuries.\| \|×1015 5.972\|\|6.94 × 1027 Wh\|\|The explosive energy of a quantity of TNT the mass of Earth.\| \|×1015 7.89\|\|9.17 × 1027 Wh\|\|Total solar output in all directions per day.\| \|×1021 1.98\|\|2.3 × 1033 Wh\|\|The explosive energy of a quantity of TNT the mass of the Sun.\| \|×1028 – 2.4×1028 4.8\|\|2.8–5.6 × 1040 Wh\|\|A type 1a supernova explosion gives off 1–×1044 joules of energy, which is about 2.4 to 4.8 hundred billion yottatons (24 to 48 octillion (2.4– 2×1028) megatons) of TNT, equivalent to the explosive force of a quantity of TNT over a trillion (1012) times the mass of the planet Earth. 4.8\| \|×1030 – 2.4×1030 4.8\|\|2.8–×1042 Wh 5.6\|\|The largest type of supernova observed, gamma-ray bursts (GRBs) release more than 1046 joules of energy.\| \|×1032 1.3\|\|×1044 Wh 1.5\|\|A merger of two black holes, first observation of gravitational waves, released ×1047 joules 5.3\| Relative effectiveness factor The relative effectiveness factor (RE factor) relates an explosive's demolition power to that of TNT, in units of the TNT equivalent/kg (TNTe/kg). The RE factor is the relative mass of TNT to which an explosive is equivalent: The greater the RE, the more powerful the explosive. This enables engineers to determine the proper masses of different explosives when applying blasting formulas developed specifically for TNT. For example, if a timber-cutting formula calls for a charge of 1 kg of TNT, then based on octanitrocubane's RE factor of 2.38, it would take only 1.0/2.38 (or 0.42) kg of it to do the same job. Using PETN, engineers would need 1.0/1.66 (or 0.60) kg to obtain the same effects as 1 kg of TNT. With ANFO or ammonium nitrate, they would require 1.0/0.74 (or 1.35) kg or 1.0/0.42 (or 2.38) kg, respectively. RE factor examples \|Ammonium nitrate (AN + <0.5% H2O)\|\|0.88\|\|2700\|\|0.42\| \|Black powder (75% KNO3 + 19% C + 6% S, ancient explosives)\|\|1.65\|\|600\|\|0.50\| \|Tanerit Simply (93% granulated AN + 6% red P + 1% C)\|\|0.90\|\|2750\|\|0.55\| \|Hexamine dinitrate (HDN)\|\|1.30\|\|5070\|\|0.60\| \|HMTD (hexamine peroxide)\|\|0.88\|\|4520\|\|0.74\| \|ANFO (94% AN + 6% fuel oil)\|\|0.92\|\|5270\|\|0.74\| \|TATP (acetone peroxide)\|\|1.18\|\|5300\|\|0.80\| \|Tovex Extra (AN water gel) commercial product\|\|1.33\|\|5690\|\|0.80\| \|Hydromite 600 (AN water emulsion) commercial product\|\|1.24\|\|5550\|\|0.80\| \|ANNMAL (66% AN + 25% NM + 5% Al + 3% C + 1% TETA)\|\|1.16\|\|5360\|\|0.87\| \|Amatol (50% TNT + 50% AN)\|\|1.50\|\|6290\|\|0.91\| \|Tritonal (80% TNT + 20% aluminium)\|\|1.70\|\|6650\|\|1.05\| \|Nickel hydrazine nitrate (NHN)\|\|2.12\|\|7000\|\|1.05\| \|Amatol (80% TNT + 20% AN)\|\|1.55\|\|6570\|\|1.10\| \|Nitrocellulose (13.5% N, NC; AKA guncotton)\|\|1.40\|\|6400\|\|1.10\| \|PBXW-126 (22% NTO, 20% RDX, 20% AP, 26% Al, 12% PU's system)\|\|1.80\|\|6450\|\|1.10\| \|Diethylene glycol dinitrate (DEGDN)\|\|1.38\|\|6610\|\|1.17\| \|PBXIH-135 EB (42% HMX, 33% Al, 25% PCP-TMETN's system)\|\|1.81\|\|7060\|\|1.17\| \|PBXN-109 (64% RDX, 20% Al, 16% HTPB's system)\|\|1.68\|\|7450\|\|1.17\| \|Picric acid (TNP)\|\|1.71\|\|7350\|\|1.17\| \|Tetrytol (70% tetryl + 30% TNT)\|\|1.60\|\|7370\|\|1.20\| \|Dynamite, Nobel's (75% NG + 23% diatomite)\|\|1.48\|\|7200\|\|1.25\| \|Torpex (aka HBX, 41% RDX + 40% TNT + 18% Al + 1% wax)\|\|1.80\|\|7440\|\|1.30\| \|Composition B (63% RDX + 36% TNT + 1% wax)\|\|1.72\|\|7840\|\|1.33\| \|Composition C-3 (78% RDX)\|\|1.60\|\|7630\|\|1.33\| \|Composition C-4 (91% RDX)\|\|1.59\|\|8040\|\|1.34\| \|Pentolite (56% PETN + 44% TNT)\|\|1.66\|\|7520\|\|1.33\| \|Semtex 1A (76% PETN + 6% RDX)\|\|1.55\|\|7670\|\|1.35\| \|Hexal (76% RDX + 20% Al + 4% wax)\|\|1.79\|\|7640\|\|1.35\| \|RISAL P (50% IPN + 28% RDX + 15% Al + 4% Mg + 1% Zr + 2% NC)\|\|1.39\|\|5980\|\|1.40\| \|Mixture: 24% nitrobenzene + 76% TNM\|\|1.48\|\|8060\|\|1.50\| \|Mixture: 30% nitrobenzene + 70% nitrogen tetroxide\|\|1.39\|\|8290\|\|1.50\| \|Octol (80% HMX + 19% TNT + 1% DNT)\|\|1.83\|\|8690\|\|1.54\| \|DADNE (1,1-diamino-2,2-dinitroethene, FOX-7)\|\|1.77\|\|8330\|\|1.60\| \|Gelignite (92% NG + 7% nitrocellulose)\|\|1.60\|\|7970\|\|1.60\| \|Plastics Gel® (in toothpaste tube: 45% PETN + 45% NG + 5% DEGDN + 4% NC)\|\|1.51\|\|7940\|\|1.60\| \|Composition A-5 (98% RDX + 2% stearic acid)\|\|1.65\|\|8470\|\|1.60\| \|Erythritol tetranitrate (ETN)\|\|1.72\|\|8100\|\|1.60\| \|PBXW-11 (96% HMX, 1% HyTemp, 3% DOA)\|\|1.81\|\|8720\|\|1.60\| \|Ethylene glycol dinitrate (EGDN)\|\|1.49\|\|8300\|\|1.66\| \|Octogen (HMX grade B)\|\|1.86\|\|9100\|\|1.70\| \|MEDINA (Methylene dinitroamine)\|\|1.65\|\|8700\|\|1.93\| : TBX (thermobaric explosives) or EBX (enhanced blast explosives), in a small, confined space, may have over twice the power of destruction. The total power of aluminized mixtures strictly depends on the condition of explosions. (kilotons of TNT) \|Davy Crockett (nuclear device)\|\|0.022\|\|23\|\|1,000\| \|Fat Man (dropped on Nagasaki) A-bomb\|\|20\|\|4600\|\|4,500\| \|Classic (one-stage) fission A-bomb\|\|22\|\|420\|\|50,000\| \|Hypothetical suitcase nuke\|\|2.5\|\|31\|\|80,000\| \|Typical (two-stage) nuclear bomb\|\|500–1000\|\|650–1120\|\|900,000\| \|W56 thermonuclear warhead\|\|1,200\|\|272–308\|\|4,960,000\| \|W88 modern thermonuclear warhead (MIRV)\|\|470\|\|355\|\|1,300,000\| \|B53 nuclear bomb (two-stage)\|\|9,000\|\|4050\|\|2,200,000\| \|B41 nuclear bomb (three-stage)\|\|25,000\|\|4850\|\|5,100,000\| \|Tsar nuclear bomb (three-stage)\|\|50,000–56,000\|\|26,500\|\|2,100,000\| \|GBU-57 bomb (Massive Ordnance Penetrator, MOP)\|\|0.0035\|\|13,600\|\|0.26\| \|Grand Slam (Earthquake bomb, M110)\|\|0.0065\|\|9,900\|\|0.66\| \|Bomb used in Oklahoma City (ANFO based on racing fuel)\|\|0.0018\|\|2,300\|\|0.78\| \|BLU-82 (Daisy Cutter)\|\|0.0075\|\|6,800\|\|1.10\| \|MOAB (non-nuclear bomb, GBU-43)\|\|0.011\|\|9,800\|\|1.13\| \|FOAB (advanced thermobaric bomb, ATBIP)\|\|0.044\|\|9,100\|\|4.83\| - Net explosive quantity - Nuclear weapon yield - Orders of magnitude (energy) - Relative effectiveness factor - Table of explosive detonation velocities - Tonne of oil equivalent, a unit of energy almost exactly 10 tonnes of TNT - "Tons (Explosives) to Gigajoules Conversion Calculator". unitconversion.org. - "Joules to Megatons Conversion Calculator". unitconversion.org. - Blast effects of external explosions (Section 4.8. Limitations of the TNT equivalent method) Archived August 10, 2016, at the Wayback Machine. - "Appendix B8 – Factors for Units Listed Alphabetically". In NIST SI Guide 2008 - Cooper, Paul W. (1996). Explosives Engineering. New York: Wiley-VCH. p. 406. ISBN 0-471-18636-8. - Muller, Richard A. (2001–2002). "Chapter 1. Energy, Power, and Explosions". Physics for Future Presidents, a textbook. ISBN 978-1-4266-2459-9. Archived from the original on 2007-05-28. - Sorin Bastea, Laurence E. Fried, Kurt R. Glaesemann, W. Michael Howard, P. Clark Souers, Peter A. Vitello, Cheetah 5.0 User's Manual, Lawrence Livermore National Laboratory, 2007. - Maienschein, Jon L. (2002). Estimating equivalency of explosives through a thermochemical approach (PDF) (Technical report). Lawrence Livermore National Laboratory. UCRL-JC-147683. - Maienschein, Jon L. (2002). Tnt equivalency of different explosives – estimation for calculating load limits in heaf firing tanks (Technical report). Lawrence Livermore National Laboratory. EMPE-02-22. - Cunningham, Bruce J. (2001). C-4/tnt equivalency (Technical report). Lawrence Livermore National Laboratory. EMPE-01-81. - "Arc blast Tri-Nitro-Toluene TNT Trotyl equivalent – ARCAD INC". arcblasts.com. - Atassi, Basma; Sirgany, Sarah; Narayan, Chandrika (December 13, 2016). "Local media: Blast at Cairo cathedral kills at least 25". CNN. Retrieved 5 April 2017. - Homer-Dixon, Thomas F; Homer-Dixon, Thomas (2002). The Ingenuity Gap. p. 249. ISBN 978-0-375-71328-6. - TECH REPS INC ALBUQUERQUE NM (1986). "Minor Scale Event, Test Execution Report". hdl:100.2/ADA269600. - "Frequently Asked Questions – Electricity". United States Department of Energy. 2009-10-06. Retrieved 2009-10-21. (Calculated from 2007 value of 936 kWh monthly usage) - "Country Comparison :: Electricity – consumption". The World Factbook. CIA. Archived from the original on 2012-01-28. Retrieved 2009-10-22. (Calculated from 2007 value of 3,892,000,000,000 kWh annual usage) - "NOAA FAQ: How much energy does a hurricane release?". National Oceanic & Atmospheric Administration. August 2001. Retrieved 2009-06-30. cites 6e14 watts continuous. - Borowski, Stanley K. (March 1996). Comparison of Fusion/Antiproton Propulsion systems (PDF). 23rd Joint Propulsion Conference. NASA Glenn Research Center. doi:10.2514/6.1987-1814. hdl:2060/19960020441. - See Currently deployed U.S. nuclear weapon yields Archived September 7, 2016, at the Wayback Machine., Complete List of All U.S. Nuclear Weapons Archived December 16, 2008, at the Wayback Machine., Tsar Bomba Archived June 17, 2016, at the Wayback Machine., all from Carey Sublette's Nuclear Weapon Archive. - "Status of World Nuclear Forces". fas.org. - "Nuclear Weapons: Who Has What at a Glance". armscontrol.org. - "Global nuclear weapons: downsizing but modernizing". Stockholm International Peace Research Institute. 13 June 2016. - Kristensen, Hans M.; Norris, Robert S. (May 3, 2016). "Russian nuclear forces, 2016". Bulletin of the Atomic Scientists. 72 (3): 125–134. doi:10.1080/00963402.2016.1170359 – via Taylor and Francis+NEJM. - Kristensen, Hans M; Norris, Robert S (2015). "US nuclear forces, 2015". Bulletin of the Atomic Scientists. 71 (2): 107. doi:10.1177/0096340215571913. - http://www.nrdc.org/nuclear/nudb/datab14.asp[dead link] - Kristensen, Hans M; Norris, Robert S (2015). "Chinese nuclear forces, 2015". Bulletin of the Atomic Scientists. 71 (4): 77. doi:10.1177/0096340215591247. - "USGS.gov: USGS WPhase Moment Solution". Earthquake.usgs.gov. Archived from the original on 13 March 2011. Retrieved 13 March 2011. - Maselli, A.; Melandri, A.; Nava, L.; Mundell, C. G.; Kawai, N.; Campana, S.; Covino, S.; Cummings, J. R.; Cusumano, G.; Evans, P. A.; Ghirlanda, G.; Ghisellini, G.; Guidorzi, C.; Kobayashi, S.; Kuin, P.; LaParola, V.; Mangano, V.; Oates, S.; Sakamoto, T.; Serino, M.; Virgili, F.; Zhang, B.- B.; Barthelmy, S.; Beardmore, A.; Bernardini, M. G.; Bersier, D.; Burrows, D.; Calderone, G.; Capalbi, M.; Chiang, J. (2013). "GRB 130427A: A Nearby Ordinary Monster". Science. 343 (6166): 48–51. arXiv: . Bibcode:2014Sci...343...48M. doi:10.1126/science.1242279. PMID 24263134. - US Army FM 3-34.214: Explosives and Demolition, 2007, page 1–2. - Whitehall Paraindistries - Thompson, A.; Taylor, B.N. (July 2008). Guide for the Use of the International System of Units (SI). NIST Special Publication. 811. National Institute of Standards and Technology. Version 3.2. - Nuclear Weapons FAQ Part 1.3 - Rhodes, Richard (2012). The Making of the Atomic Bomb (25th Anniversary ed.). Simon & Schuster. ISBN 978-1-4516-7761-4. - Cooper, Paul W. (1996), Explosives Engineering, New York: Wiley-VCH, ISBN 0-471-18636-8 - HQ Department of the Army (2004) , Field Manual 5-25: Explosives and Demolitions, Washington, D.C.: Pentagon Publishing, pp. 83–84, ISBN 0-9759009-5-1 - Explosives - Compositions, Alexandria, VA: GlobalSecurity.org, retrieved September 1, 2010 - Urbański, Tadeusz (1985) , Chemistry and Technology of Explosives, Volumes I–IV (second ed.), Oxford: Pergamon - Mathieu, Jörg; Stucki, Hans (2004), "Military High Explosives", CHIMIA International Journal for Chemistry, Schweizerische Chemische Gesellschaft, 58 (6): 383–389, doi:10.2533/000942904777677669, ISSN 0009-4293 - 3. Thermobaric Explosives, Advanced Energetic Materials, 2004., The National Academies Press, nap.edu, 2004	<urn:uuid:84a32248-e3bc-4c1f-b627-04ab19d3d5a6>	3.515625	6,527	Knowledge Article	Science & Tech.	93.979542	95,577,541
Hawking state, named after James Hartle and Stephen Hawking, is a proposal concerning the james hartle gravity pdf of the universe prior to the Planck epoch. Hartle and Hawking suggest that if we could travel backward in time toward the beginning of the universe, we would note that quite near what might have otherwise been the beginning, time gives way to space such that at first there is only space and no time. Big Bang, the concept of a beginning of the universe is meaningless. Hawking proposal, the universe has no origin as we would understand it: the universe was a singularity in both space and time, pre-Big Bang. Hawking state is the wave function of the Universe—a notion meant to figure out how the Universe started—that is calculated from Feynman’s path integral. More precisely, it is a hypothetical vector in the Hilbert space of a theory of quantum gravity that describes this wave function. Universe, where D is the spacetime dimension. Hawking state is the path integral over all D-dimensional geometries that have the required induced metric on their boundary.	<urn:uuid:d665943d-7d34-4ad6-8de0-79067ecef07f>	3.109375	226	Knowledge Article	Science & Tech.	36.778185	95,577,548
Hawksbill sea turtle research in Costa RicaJune 28 2018 Hawksbill sea turtles are particularly threatened in the Eastern Pacific ocean, with only 500 nesting females left in the whole region. We have discovered that a small population of juvenile hawksbill sea turtles uses the rocky reefs around the waters of Costa Rica to feed and grow. Join me as I explore the Pacific coast of Costa Rica, studying these animals, following their movements, and working with the local communities to ensure the survival of this species. Accept contributions for your expediton by providing us a few details. We will create an account on your behalf at WePay. If you haven't already registered with WePay, they will send you an email to complete your registration. Day 2, July 5th (1/2): Matapalito Bay Matapalito bay has proved to be one of the most important foraging grounds for green sea turtles and hawksbill sea turtles in the northern pacific coast of Costa Rica. Sea turtle scientists have debated about the taxonomic classification of green turtles for decades. For some, Chelonia mydas should be considered a single species, even though its populations have different physical traits, the genetics is basically the same. After several years of studying in-water sea turtle populations in the area, researchers from Equipo Tora Carey have discovered that Matapalito Bay is not visited only by Pacific green sea turtles (that we call black sea turtles, and some scientists consider a sub species of the green turtle) but its also visited by green sea turtles from the Indopacific Ocean, with a distinctive morph and colorations of their shell!! During our research we had the chance to capture both a black turtle and an indopacific green turtle, we took tissue samples that will be used for genetic studies to help us solve the dilemma of the green turtle. Can you tell the difference?? (Look at pictures) I am very sorry for the delayed update, on the field connection was not always available. Now that I'll be staying in the capital for a couple of days I'll be updating the exploration and giving you a very detailed description of the amazing things we encountered! First of all, I want to thank Lush Cosmetics North America for making this trip happening as well as the crew from the Sharkwater, and the Fins Attached organization. Day 1, July 4rd: El Jobo El Jobo is a small community in northern Costa Rica, here the Equipo Tora-Carey (www.equipotoracarey.org)) has been working on foraging grounds and nesting beaches of Pacific green turtles and Hawksbill turtles. We joined them as we went diving around the site, due to bad visibility we were not able to catch any turtles for our research, even though we did encounter a big female green sea turtle during our test dive. Tomorrow we will go snorkeling with the locals at a site were sea turtles are frecuently caught as part of the team's research. Hopefully we will have the chance to find hawksbill sea turtles!! We have departed!! The expedition aboard the Sharkwater has officially started! Tomorrow we will dock at El Jobo, here, the Equipo Tora-Carey has been studying green turtles and ocasional hawksbill sea turtles at nesting beaches and foraging grounds. Barely a month ago, a nesting hawksbill sea turtle was tagged with a satellite transmitter by this team for the first time in Costa Rica! Hopefully they will share some cool information with us! We will have two morning dives, and in the afternoon we will set up a sea turtle net in order to catch and monitor sea turtles at foraging grounds! For my next field campaign, I will have the support of the SharkWater research vessel. This incredible boat is owned by Fins Attached, and organization based in the United States. Taken from their website (www.finsattached.org) : "Sharkwater is a 134-foot vessel that was originally built in Japan and used by Japanese fisheries but now has been repurposed for the good of our oceans through the marine research and conservation mission of Fins Attached. Sharkwater will be a host to many different professions within the field. Scientists, non-governmental organizations (NGOs), marine science students, and documentary crews will have the opportunity to conduct fieldwork, and to achieve the objectives of Fins Attached." Getting very excited about this! My name is Daniel Arauz, I'm a National Geographic Explorer part of the new Photo Ark EDGE fellows (www.edgeofexistence.com). For the past years I have been working with the Rescue Center for Endangered Marine Species (CREMA) on a recently discovered foraging site for the critically endangered hawksbill sea turtle in the Pacific coast of Costa Rica. My main objective is to track these animals using acoustic telemetry in order to find new feeding grounds, as well as engaging the local communities in the protection and conservation of this emblematic species. I will be exploring the northern Pacific coast of Costa Rica, joining marine biologists and conservationists on their efforts to protect marine environments in my country. We will be looking for sea turtles, sharks, manta rays, and other marine fauna moving across different sites in order to strengthen the conservation efforts made by the local authorities.	<urn:uuid:33d2d8de-6c0c-4fc9-b833-88668b52bc7b>	3.203125	1,111	Personal Blog	Science & Tech.	42.974827	95,577,556
7 Reactive nonmetal 15 Reactive nonmetal 83 Post-transition metal 115 unknown chemical properties A pnictogen // is one of the chemical elements in group 15 of the periodic table. This group is also known as the nitrogen family. It consists of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and perhaps the chemically uncharacterized synthetic element moscovium (Mc). In modern IUPAC notation, it is called Group 15. In CAS and the old IUPAC systems it was called Group VA and Group VB respectively (pronounced "group five A" and "group five B", "V" for the Roman numeral 5). In the field of semiconductor physics, it is still usually called Group V. The "five" ("V") in the historical names comes from the "pentavalency" of nitrogen, reflected by the stoichiometry of compounds such as N2O5. They have also been called the pentels. \|Z\|\|Element\|\|Electrons per shell\| \|15\|\|phosphorus\|\|2, 8, 5\| \|33\|\|arsenic\|\|2, 8, 18, 5\| \|51\|\|antimony\|\|2, 8, 18, 18, 5\| \|83\|\|bismuth\|\|2, 8, 18, 32, 18, 5\| This group has the defining characteristic that all the component elements have 5 electrons in their outermost shell, that is 2 electrons in the s subshell and 3 unpaired electrons in the p subshell. They are therefore 3 electrons short of filling their outermost electron shell in their non-ionized state. The Russell-Saunders term symbol of the ground state in all elements in the group is 4S3⁄2. The most important elements of this group are nitrogen (N), which in its diatomic form is the principal component of air, and phosphorus (P), which, like nitrogen, is essential to all known forms of life. Binary compounds of the group can be referred to collectively as pnictides. The spelling derives from the Greek verb πνίγειν (pnígein), to "choke" or "stifle", which is a property of molecular nitrogen in the absence of oxygen; it can also be used as a mnemonic for the two most common members, P and N. The name pentels (from Greek πέντε, pénte, five) was also used for this group at one time, stemming from the earlier group naming convention (Group VB). Pnictide compounds tend to be exotic. Various properties that some pnictides have include being diamagnetic and paramagnetic at room temperature, being transparent, and generating electricity when heated. Other pnictides include the ternary rare-earth main-group variety of pnictides. These are in the form of REaMbPnc, where M is a carbon group or boron group element and Pn is any pnictogen except nitrogen. These compounds are between ionic and covalent compounds and thus have unusual bonding properties. These elements are also noted for their stability in compounds due to their tendency for forming double and triple covalent bonds. This is the property of these elements which leads to their potential toxicity, most evident in phosphorus, arsenic and antimony. When these substances react with various chemicals of the body, they create strong free radicals not easily processed by the liver, where they accumulate. Paradoxically, it is this strong bonding which causes nitrogen and bismuth's reduced toxicity (when in molecules), as these form strong bonds with other atoms which are difficult to split, creating very unreactive molecules. For example, N2, the diatomic form of nitrogen, is used as an inert gas in situations where using argon or another noble gas would be too expensive. The upper pnictogens, that is, nitrogen, phosphorus, and arsenic tend to form −3 charges. Antimony and bismuth can either take on a +3 or +5, by losing its p-shell electrons or losing its p-shell and s-shell electrons, respectively. The pnictogens consist of two nonmetals (one gas, one solid), two metalloids, one metal, and one element with unknown chemical properties. All the elements in the group are solids at room temperature, except for nitrogen which is gaseous at room temperature. Nitrogen and bismuth, despite both being pnictogens, are very different in their physical properties. For instance, at STP nitrogen is a transparent nonmetallic gas, while bismuth is a silvery-white metal. The densities of the pnictogens increase towards the heavier pnictogens. Nitrogen's density is 0.001251 g/cm3 at STP. Phosphorus's density is 1.82 g/cm3 at STP, arsenic's is 5.72 g/cm3, antimony's is 6.68 g/cm3, and bismuth's is 9.79 g/cm3. Nitrogen's melting point is −210 °C and its boiling point is −196 °C. Phosphorus has a melting point of 44 °C and a boiling point of 280 °C. Arsenic is one of only two elements to sublimate at standard pressure; it does this at 603 °C. Antimony's melting point is 631 °C and its boiling point is 1587 °C. Bismuth's melting point is 271 °C and its boiling point is 1564 °C. The nitrogen compound sal ammoniac (ammonium chloride) has been known since the time of the Ancient Egyptians. In the 1760s two scientists, Henry Cavendish and Joseph Priestley, isolated nitrogen from air, but neither realized the presence of an undiscovered element. It was not until several years later, in 1772, that Daniel Rutherford realized that the gas was indeed nitrogen. The scientist Hennig Brandt first discovered phosphorus in Hamburg in 1669. Brandt produced the element by heating evaporated urine and condensing the resulting phosphorus vapor in water. Brandt initially thought that he had discovered the Philosopher's Stone, but eventually realized that this was not the case. Arsenic compounds have been known for at least 5000 years, and the ancient Greek Theophrastus recognized the arsenic minerals called realgar and orpiment. Elemental arsenic was discovered in the 13th century by Albertus Magnus. Antimony was well-known to the ancients. A 5000-year-old vase made of nearly pure antimony exists in the Louvre. Antimony compounds were used in dyes in the Babylonian times. The antimony mineral stibnite may have been a component of Greek fire. Bismuth was first discovered by an alchemist in 1400. Within 80 years of bismuth's discovery, it had applications in printing and decorated caskets. The Incas were also using bismuth in knives by 1500. Bismuth was originally thought to be the same as lead, but in 1753, Claude François Geoffroy proved that bismuth was different from lead. The term "pnictogen" was suggested by the Dutch chemist Anton Eduard van Arkel in the early 1950s. It is also spelled "pnicogen" or "pnigogen". The term "pnicogen" is rarer than the term "pnictogen", and the ratio of academic research papers using "pnictogen" to those using "pnicogen" is 2.5 to 1. It comes from the Greek root πνιγ- (choke, strangle), and thus the word "pnictogen" is also a reference to the Dutch and German names for nitrogen (stikstof, Stickstoff, "suffocating substance", i.e. portion of air unsuitable for breathing). Hence, "pnictogen" could be translated as "suffocation maker". The word "pnictide" also comes from the same root. Nitrogen makes up 25 parts per million of the earth's crust, 5 parts per million of soil on average, 100 to 500 parts per trillion of seawater, and 78% of dry air. The majority of nitrogen on earth is in the form of nitrogen gas, but some nitrate minerals do exist. Nitrogen makes up 2.5% of a typical human by weight. Phosphorus makes up 0.1% of the earth's crust, making it the 11th most abundant element there. Phosphorus makes up 0.65 parts per million of soil, and 15 to 60 parts per billion of seawater. There are 200 million metric tons of accessible phosphates on earth. Phosphorus makes up 1.1% of a typical human by weight. Phosphorus occurs in minerals of the apatite family which are the main components of the phosphate rocks. Arsenic makes up 1.5 parts per million of the earth's crust, making it the 53rd most abundant element there. The soils contain 1 to 10 parts per million of arsenic, and seawater contains 1.6 parts per billion of arsenic. Arsenic makes up 100 parts per billion of a typical human by weight. Some arsenic exists in elemental form, but most arsenic is found in the arsenic minerals orpiment, realgar, arsenopyrite, and enargite. Antimony makes up 0.2 parts per million of the earth's crust, making it the 63rd most abundant element there. The soils contain 1 part per million of antimony on average, and seawater contains 300 parts per trillion of antimony on average. A typical human contains 28 parts per billion of antimony by weight. Some elemental antimony occurs in silver deposits. Bismuth makes up 48 parts per billion of the earth's crust, making it the 70th most abundant element there. The soils contain approximately 0.25 parts per million of bismuth, and seawater contains 400 parts per trillion of bismuth. Bismuth most commonly occurs as the mineral bismuthinite, but bismuth also occurs in elemental form or in sulfide ores. Moscovium is produced several atoms at a time in particle accelerators. Most arsenic is prepared by heating the mineral arsenopyrite in the presence of air. This forms As4O6, from which arsenic can be extracted via carbon reduction. However, it is also possible to make metallic arsenic by heating arsenopyrite at 650 to 700 °C without oxygen. With sulfide ores, the method by which antimony is produced depends on the amount of antimony in the raw ore. If the ore contains 25% to 45% antimony by weight, then crude antimony is produced by smelting the ore in a blast furnace. If the ore contains 45% to 60% antimony by weight, antimony is obtained by heating the ore, also known as liquidation. Ores with more than 60% antimony by weight are chemically displaced with iron shavings from the molten ore, resulting in impure metal. If an oxide ore of antimony contains less than 30% antimony by weight, the ore is reduced in a blast furnace. If the ore contains closer to 50% antimony by weight, the ore is instead reduced in a reverberatory furnace. Antimony ores with mixed sulfides and oxides are smelted in a blast furnace. Bismuth minerals do occur, in particular in the form of sulfides and oxides, but it is more economic to produce bismuth as a by-product of the smelting of lead ores or, as in China, of tungsten and zinc ores. Moscovium is produced a few atoms at a time in particle accelerators. - Liquid nitrogen is a commonly used cryogenic liquid. - Nitrogen in the form of ammonia a nutrient critical to most plants' survival. Synthesis of ammonia accounts for about 1-2% of the world's energy consumption and the majority of reduced nitrogen in food. - Phosphorus is used in matches and incendiary bombs. - Phosphate fertilizer helps feed much of the world. - Arsenic was historically used as a Paris green pigment, but is not used this way anymore, due to arsenic's extreme toxicity. - Arsenic in the form of organoarsenic compounds is sometimes used in chicken feed - Antimony is alloyed with lead to produce some bullets. - Antimony currency was briefly used in the 1930s in parts of China, but this use was discontinued as antimony is soft and toxic - Bismuth subsalicylate is the active ingredient in Pepto-Bismol. Nitrogen is a component of molecules critical to life on earth, such as DNA and amino acids. Nitrates occur in some plants,due to bacteria present in the nodes of the plant.This is seen in leguminous plants such as peas.[clarification needed] such as spinach and lettuce. A typical 70-kilogram human contains 1.8 kilograms of nitrogen. Phosphorus in the form of phosphates occur in compounds important to life, such as DNA and ATP. Humans consume approximately 1 grams of phosphorus per day. Phosphorus is found in foods such as fish, liver, turkey, chicken, and eggs. Phosphate deficiency is a problem known as hypophosphatemia. A typical 70-kilogram human contains 480 grams of phosphorus. Arsenic promotes growth in chickens and rats, and may be essential for humans. Arsenic has been shown to be helpful in metabolizing the amino acid arginine. There are 7 milligrams of arsenic in a typical 70-kilogram human. Antimony is not known to have a biological role. Plants take up only trace amounts of antimony. There are approximately 2 milligrams of antimony in a typical 70-kilogram human. Bismuth is not known to have a biological role. Humans ingest on average less than 20 micrograms of bismuth per day. There is less than 500 micrograms of bismuth in a typical 70-kilogram human. Nitrogen gas is completely nontoxic, but breathing in pure nitrogen gas is deadly, because it causes nitrogen asphyxiation. The buildup of nitrogen bubbles in the blood, such as during scuba diving, can cause a condition known as the "bends" (decompression sickness). Many nitrogen compounds, such as hydrogen cyanide and explosives are also highly dangerous. White phosphorus, an allotrope of phosphorus, is toxic, with 1 milligram per kilo bodyweight being a lethal dose. White phosphorus usually kills humans within a week of ingestion by attacking the liver. Breathing in phosphorus in its gaseous form can cause an industrial disease called "phossy jaw", which eats away the jawbone. White phosphorus is also highly flammable. Some organophosphorus compounds can fatally block certain enzymes in the human body. Elemental arsenic is toxic, as are many of its inorganic compounds; however some of its organic compounds can promote growth in chickens. The lethal dose of arsenic for a typical adult is 200 milligrams, and can cause diarrhea, vomiting, colic, dehydration, and coma. Death from arsenic poisoning typically occurs within a day. Antimony is mildly toxic. Additionally, wine steeped in antimony containers can induce vomiting. When taken in large doses, antimony causes vomiting in a victim, who then appears to recover before dying several days later. Antimony attaches itself to certain enzymes and is difficult to dislodge. Stibine, or SbH3 is far more toxic than pure antimony. Bismuth itself is largely nontoxic, although consuming too much of it can damage the liver. Only one person has ever been reported to have died from bismuth poisoning. However, consumption of soluble bismuth salts can turn a person's gums black. - Oxypnictide, including superconductors discovered in 2008. - Ferropnictide, including oxypnictide superconductors. - Connelly, NG; Damhus, T, eds. (2005). "section IR-3.5: Elements in the periodic table". Nomenclature of Inorganic Chemistry: IUPAC Recommendations 2005 (PDF). Cambridge, United Kingdom: RSC Publishing. p. 51. ISBN 0-85404-438-8. - Fluck, E (1988). "New notations in the periodic table" (PDF). Pure and Applied Chemistry. 60 (3): 431–6. doi:10.1351/pac198860030431. - Adachi, S (2005). Properties of Group-IV, III-V and II-VI Semiconductors. Wiley Series in Materials for Electronic & Optoelectronic Applications. Volume 15. Hoboken, New Jersey: John Wiley & Sons. ISBN 978-0470090329. - Girolami, GS (2009). "Origin of the Terms Pnictogen and Pnictide". Journal of Chemical Education. 86 (10): 1200–1. Bibcode:2009JChEd..86.1200G. doi:10.1021/ed086p1200. - Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils, ed., Inorganic Chemistry, translated by Eagleson, Mary; Brewer, William, San Diego/Berlin: Academic Press/De Gruyter, p. 586, ISBN 0-12-352651-5 - "Pnicogen – Molecule of the Month". University of Bristol - Boudreaux, Kevin A. "Group 5A — The Pnictogens". Department of Chemistry, Angelo State University, Texas - Gray, Theodore (2010). The Elements. - Jackson, Mark (2001), Periodic Table Advanced, ISBN 1572225424 - Emsley, John (2011), Nature's Building Blocks, ISBN 978-0-19-960563-7 - Girolami, Gregory S. (2009). "Origin of the Terms Pnictogen and Pnictide". Journal of Chemical Education. American Chemical Society. 86 (10): 1200. Bibcode:2009JChEd..86.1200G. doi:10.1021/ed086p1200. - "nitrogen (N) \| chemical element". Encyclopædia Britannica. - "phosphorus (P) \| chemical element". Encyclopædia Britannica. - "arsenic (As) \| chemical element". Encyclopædia Britannica. - Butterman, C.; Carlin, Jr., J.F. (2003). Mineral Commodity Profiles: Antimony. United States Geological Survey. - Bell, Terence. "Metal Profile: Bismuth". About.com. - Kean, Sam (2011), The Disappearing Spoon - Phosphorus in diet. nlm.nih.gov	<urn:uuid:0c79c56e-eb7c-4b9d-b464-d07723682029>	3.546875	4,040	Knowledge Article	Science & Tech.	53.793959	95,577,582
There exists a plethora of potential uses for plants which range from being food-based, aesthetically pleasing, medical-based, economic and cultural. Since the beginning of civilization, animals and human beings have been utilizing plants to fulfill their needs and still today, plant species remain to possess an integral role in all ecosystems. Early humans, such as those residing in hunter gatherer societies, used plants in their day-to-day lives for clothing, food, as medicine and for building miscellaneous items. Although hunter gatherer societies did not have the knowledge or tools we have today regarding plants and how to use them, they knew that these species were critical to their survival. Native Americans also were aware of the strong powers plants can have, such as healing-based ones, and for these individuals, plants were not just beneficial to their health, but they also held meaningful cultural significance. The use of plants as a food source for humans and even for feeding animals and livestock was completely revolutionized with the emergence of agriculture. This also led to major economic benefits. In modern society, plants are traded and sold all over the world and furthermore, there has been insightful and successful progress in the field of genetic engineering. Other important applications of plants include using them as spices, perfumes and novelties, for housing and tools, and for designing clothing and personal décor. These plant-based functions are both economic and social in nature, depending on what end of the trade you are on. Nevertheless, plants have and also will play a pivotal role in the biosphere and understanding their complex functionality is critical to plant biology.© BrainMass Inc. brainmass.com July 16, 2018, 12:19 pm ad1c9bdddf	<urn:uuid:a0ec3126-ee1c-4885-bb38-fd8e6ca4aed2>	3.203125	352	Knowledge Article	Science & Tech.	33.349056	95,577,594
The research developed by Joukowski to determine the force exerted by a flow on a body around which it is flowing eventually led to the theoretical foundation for practical aircraft construction, and the methods of conformal mapping played an important role in modern aviation. During the 1930s Theodorsen’s iterative method became a pioneer in transforming the exterior of the unit circle onto the exterior of an almost circular contour. But in the potential flow analysis of airfoils, James’s method developed in 1971 turns out to be more successful for all types of contours which do not have corner singularity. We shall develop Joukowski mapping functions, compare numerical solutions of single-element airfoils by both Theodorsen’s and James’s iterative methods, unfold the mechanism of divergence of Theodorsen’s method in the cases where the image boundary is not almost circular, and finally analyze multiple-element airfoils by using von Karman-Trefftz transformations and FFT with Garrick’s method of conjugate functions. KeywordsUnit Circle Corner Singularity Circular Contour Conjugate Harmonic Function Mobius Transformation Unable to display preview. Download preview PDF.	<urn:uuid:f1b8e556-a655-49dd-9bb8-a83637fc43be>	2.9375	251	Truncated	Science & Tech.	14.284029	95,577,595
15 Harden against Space Radiation (Contributed by Dr James K. Woosley) Some amount of hardening against space radiation is already incorporated into satellite design. However, as we learn more about the space radiation environment and particularly solar Oares, the risk appears to be greater than was first supposed. Future generations of satellites must be shielded or include protective measures against the worst-case radiation loads of the most intense solar flare foreseeable. This hardening will also be helpful in the worst-case event of a nuclear detonation in space. KeywordsSpace System Space Radiation Satellite Design Solar Storm Single Event Effect Unable to display preview. Download preview PDF. - 1.LaBel, K.A., et al. Emerging Radiation Hardness Assurance (RHA) Issues: A NASA Approach for Space Flight Programs. Nuclear Science, IEEE Transactions, 45(6), 2727-2736 (1998).Google Scholar	<urn:uuid:4f342977-9267-4360-b450-9841b3589ecf>	3.359375	187	Truncated	Science & Tech.	39.288827	95,577,596
EESC 3318 Alternative Energy: Why Aren't We There Yet? (Fall: 3 ) Oil, gas, and coal have historically provided the foundation of our domestic and global energy needs. It is becoming increasingly apparent that, to attain a sustainable society, we must shift away from these polluting, non-renewable fossil fuel resources. Alternative energy sources are non-polluting and renewable and are therefore logical replacements. Some are confused, however, as to why more progress hasn’t been made towards phasing out fossil fuels and transitioning to alternative energy. This course will delve into the benefits and cons of fossil fuels, as well as the stumbling blocks to implementing the following alternative energy technologies: hydropower, wave power, biomass, solar, geothermal, wind, hydrogen and nuclear energies. Instructor(s): Jennifer Cole Last Updated: 24-Jun-17	<urn:uuid:88eb2f16-456e-4f36-91bd-f1e5fafd95be>	2.984375	181	Product Page	Science & Tech.	21.073182	95,577,622
Jaguar electric boat breaks the world’s speed record with its electric boat. As we know Jaguar is famous for its luxury vehicle brand of Jaguar Land Rover, and not only luxury vehicles but also electric cars, and what about electric boats? It really sounds fantastic, they released not only electric boat but also electric boat brakes the speed record. Planetologists hope, that Mars won’t suffer in October, 2014 during comet flight by it. In spite of the fact that Mars is far from Earth, is also as well as our planet periodically is under the threat of rapprochement with comets and asteroids. So, by estimates of scientists, in October 2014 the comet of C/2013 A1 will approach with the Red Planet. This comet was found for the first time on January 3, 2013 by the Australian astronomer Robert Maknotom in observatory the Siding Spring with the help 0.5м Schmidt’s mirror and lens telescope. A comet Maknota and her trajectory of flight watched about two months in the course of what it was calculated that there is a small probability of collision of a comet with Mars on October 19, 2014. When passing by a comet of an orbit of Mars its relative speed will make 56 km/s. Diameter of a shock crater in case of collision will be approximately ten times more than a comet kernel. Diameter of a kernel is estimated in the range from 8 to 50 kilometers. By estimates of some astronomers, it is supposed, that the comet Maknota can pass at distance of 41300 kilometers from the central point of Mars. In April, 2013 of NASA published new data according to which collision of a comet of C/2013 A1 with Mars is improbable. By new estimates, the probability of this event makes 1:120000 instead of former 1:8000. The comet will pass at distance in 110 000 km from Mars at 18:51 GMT on October 19, 2014. The last data obtained by workers from Laboratory of Jet Movement, say that probability of collision of a comet C/2013 A1 with Mars decreased with 1 to 8 000 to 1 to 120 000.	<urn:uuid:f91477b4-ae73-4e5a-8b4d-49d6dc77eab9>	2.6875	435	Truncated	Science & Tech.	61.039613	95,577,646
Sir Joseph John Thomson (1856-1940) was a British physicist who is credited with the discovery of the electron. First published in 1933, this volume is one of two books making up the third edition of a 1903 original by Thomson. The text was greatly enlarged for this edition, which resulted in its division into two parts, and incorporates numerous advances in research relating to the discharge of electricity through gases. Numerous illustrative figures are provided throughout. This book will be of value to anyone with an interest in Thomson and his contribution to the development of physics. \|Publication date:\|\|13th June 2013\| \|Author:\|\|J. J. Thomson, G. P. Thomson\| \|Publisher:\|\|Cambridge University Press\| \|Categories:\|\|Physics of gases, History of science,\|	<urn:uuid:1319a9eb-a967-492a-b9b7-acc2cb37037c>	3.078125	167	Product Page	Science & Tech.	44.964096	95,577,650
Heliospheric current sheet The heliospheric current sheet is the surface within the Solar System where the polarity of the Sun's magnetic field changes from north to south. This field extends throughout the Sun's equatorial plane in the heliosphere. The shape of the current sheet results from the influence of the Sun's rotating magnetic field on the plasma in the interplanetary medium (solar wind). A small electrical current flows within the sheet, about 10−10 A/m². The thickness of the current sheet is about 10,000 km near the orbit of the Earth. The underlying magnetic field is called the interplanetary magnetic field, and the resulting electric current forms part of the heliospheric current circuit. The heliospheric current sheet is also sometimes called the interplanetary current sheet. Ballerina's skirt shape As the Sun rotates, its magnetic field twists into a Parker spiral, a form of an Archimedean spiral, as it extends through the solar system. This phenomenon is named after Eugene Parker's work: he predicted the solar wind and many of its associated phenomena in the 1950s. The spiral nature of the heliospheric magnetic field had been noted earlier by Hannes Alfvén, based on the structure of comet tails. The influence of this spiral-shaped magnetic field on the interplanetary medium (solar wind) creates the largest structure in the Solar System, the heliospheric current sheet. Parker's spiral magnetic field was divided in two by a current sheet, a mathematical model first developed in the early 1970s by Schatten. It warps into a wavy spiral shape that has been likened to a ballerina's skirt. The waviness of the current sheet is because of the magnetic field dipole axis' tilt angle to the solar rotation axis and variations from an ideal dipole field. Unlike the familiar shape of the field from a bar magnet, the Sun's extended field is twisted into an arithmetic spiral by the magnetohydrodynamic influence of the solar wind. The solar wind travels outward from the Sun at a uniform rate, but an individual jet of solar wind from a particular feature on the Sun's surface rotates with the solar rotation, making a spiral pattern in space. Unlike the jet from a sprinkler, the solar wind is tied to the magnetic field by MHD effects, so that magnetic field lines are tied to the material in the jet and take on an arithmetic spiral shape. The cause of the ballerina spiral shape has sometimes been called the "garden sprinkler effect" or "garden hose effect", because it is likened to a lawn sprinkler with nozzle that moves up and down while it spins. The stream of water represents the solar wind. The Parker spiral shape of the solar wind changes the shape of the Sun's magnetic field in the outer solar system: beyond about 10-20 astronomical units from the Sun, the magnetic field is nearly toroidal (pointed around the equator of the Sun) rather than poloidal (pointed from the North to the South pole, as in a bar magnet) or radial (pointed outward or inward, as might be expected from the flow of the solar wind if the Sun were not rotating). The spiral shape also greatly amplifies the strength of the solar magnetic field in the outer solar system. The Parker spiral may be responsible for the differential solar rotation, in which the Sun's poles rotate more slowly (about a 35-day rotation period) than the equator (about a 27-day rotation period). The solar wind is guided by the Sun's magnetic field and hence largely emanates from the polar regions of the Sun; the induced spiral shape of the field causes a drag torque on the poles due to the magnetic tension force. The heliospheric current sheet rotates along with the Sun with a period of about 25 days, during which time the peaks and troughs of the skirt pass through the Earth's magnetosphere, interacting with it. Near the surface of the Sun, the magnetic field produced by the radial electric current in the sheet is of the order of 5×10−6 T. The magnetic field at the surface of the Sun is about 10−4 teslas. If the form of the field were a magnetic dipole, the strength would decrease with the cube of the distance, resulting in about 10−11 teslas at the Earth's orbit. The heliospheric current sheet results in higher order multipole components so that the actual magnetic field at the Earth due to the Sun is 100 times greater. The electric current in the heliospheric current sheet has a radial component (directed inward) as well as an azimuthal component, the radial circuit being closed by outward currents aligned with the Sun's magnetic field in the solar polar regions. The radial current in the circuit is on the order of 3×109 amperes. As a comparison with other astrophysical electric currents, the Birkeland currents that supply the Earth's aurora are about a thousand times weaker at a million amperes. The maximum current density in the sheet is on the order of 10−10 A/m² (10−4 A/km²). The heliospheric current sheet was discovered by John M. Wilcox and Norman F. Ness, who published their finding in 1965. Hannes Alfvén and Per Carlqvist speculate on the existence of a galactic current sheet, a counterpart of the heliospheric current sheet, with an estimated galactic current of 1017 to 1019 amperes, that might flow in the plane of symmetry of the galaxy. - "The heliospheric current sheet" Smith, E. J, Journal of Geophysical Research 106, A8, 15819, 2001. - A Star with two North Poles Archived 2009-07-18 at the Wayback Machine., April 22, 2003, Science @ NASA - Riley, Pete; Linker, J. A.; Mikić, Z., "Modeling the heliospheric current sheet: Solar cycle variations", (2002) Journal of Geophysical Research (Space Physics), Volume 107, Issue A7, pp. SSH 8-1, CiteID 1136, DOI 10.1029/2001JA000299. (Full text Archived 2009-08-14 at the Wayback Machine.) - "Artist's Conception of the Heliospheric Current Sheet". Archived from the original on September 1, 2006. Retrieved 2005-11-20. - Israelevich, P. L., et al., "MHD simulation of the three-dimensional structure of the heliospheric current sheet" (2001) Astronomy and Astrophysics, v.376, p.288-291 - Parker, E. N., "Dynamics of the Interplanetary Gas and Magnetic Fields", (1958) Astrophysical Journal, vol. 128, p.664 - "On the theory of comet tails", H. Alfvén, Tellus 9, 92, 1957. - "Current Sheet Magnetic Model for the Solar Corona", K. H. Schatten, Cosmic Electrodynamics, 2, 232-245, 1971. - Rosenberg, R. L. and P. J. Coleman, Jr., Heliographic latitude dependence of the dominant polarity of the interplanetary magnetic field, J. Geophys. Res., 74 (24), 5611-5622, 1969. - Wilcox, J. M.; Scherrer, P. H.; Hoeksema, J. T., "The origin of the warped heliospheric current sheet" (1980) - Owens, M. J.; Forsyth, R. J. (2013). "The Heliospheric Magnetic Field". Living Reviews in Solar Physics. 10: 11. Bibcode:2013LRSP...10....5O. doi:10.12942/lrsp-2013-5. - Louise K. Harra, Keith O. Mason, Space Science 2004, Imperial College Press, ISBN 1-86094-361-6 - Smith, E., "The Sun, Solar Wind, and Magnetic Field Archived 2008-02-05 at the Wayback Machine.", Jul 1999, Proceedings of the International School of Physics Enrico FERMI Varenna, Italy - Barbier, Beth. "NASA's Cosmicopia -- Sun -- Sun's Magnetic Field". - Wilcox, John M.; Ness, Norman F. (1965). "Quasi-Stationary Corotating Structure in the Interplanetary Medium". Journal of Geophysical Research. 70 (23): 5793–5805. Bibcode:1965JGR....70.5793W. doi:10.1029/JZ070i023p05793. - Alfvén, Hannes; Carlqvist, Per (1978). "Interstellar clouds and the formation of stars". Astrophysics and Space Science. 55 (2): 487–509. Bibcode:1978Ap&SS..55..487A. doi:10.1007/bf00642272. - The Heliospheric Current Sheet - A Star With Two North Poles (features animation) - The interplanetary magnetic field - 3-Dimensional View of the Heliospheric Current Sheet - NASA Astrophysics Data System article references (Online full text articles)	<urn:uuid:62df9501-ec50-4da3-a2be-5f0b66a86bf2>	4.0625	1,961	Knowledge Article	Science & Tech.	66.963458	95,577,660
Common name: Mummichog available through www.itis.gov Identification: Smith (1985); Robins and Ray (1986); Menhinick (1991). Size: 12.5 cm. Native Range: Marine, brackish, and occasionally freshwaters from the Gulf of St. Lawrence to northeastern Florida (Robins and Ray 1986). Interactive maps: Point Distribution Maps Puerto Rico & Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Fundulus heteroclitus are found here. Table last updated 5/25/2018 † Populations may not be currently present. Means of Introduction: This species was introduced into ponds in New Hampshire, apparently via bait bucket release (Scarola 1973). It was transferred to far western Pennsylvania from the Delaware River drainage of the eastern part of the state (Raney 1938, cited in Trautman 1981), possibly as a baitfish. The other collections in Pennsylvania are believed to be bait bucket introductions (Denoncourt et al. 1975a, 1978). Status: Previously established or locally established in New Hampshire and Pennsylvania (Scarola 1973; Trautman 1981). Denoncourt et al. (1975a) reported only two specimens from Sandy Run, and one specimen from the Juniata River. Established in the lower Susquehanna and Delaware drainages (Denoncourt et al., 1978). Impact of Introduction: Unknown. References: (click for full references) Denoncourt, R. F., T. B. Robbins, and R. Hesser. 1975a. Recent introductions and reintroductions to the Pennsylvania fish fauna of the Susquehanna River drainage above Conowingo Dam. Proceedings of the Pennsylvania Academy of Science 49:57-58. Denoncourt, R.F., J.C. Fisher, and K.M. Rapp. 1978. A freshwater population of the Mummichog, Fundulus heteroclitus, from the Susquehanna River drainage in Pennsylvania. Estuaries and Coasts 1(4):269-272. Raney, E. C. 1938. The distribution of the fishes of the Ohio drainage basin of western Pennsylvania. Doctoral dissertation. Cornell University, Ithaca, NY. 102 pp. Robins, C. R., G. C. Ray, and J. Douglass. 1986. A field guide to Atlantic Coast fishes of North America. The Peterson Guide Series, volume 32. Houghton Mifflin Company, Boston, MA. Scarola, J. F. 1973. Freshwater fishes of New Hampshire. New Hampshire Fish and Game Department, Division of Inland and Marine Fisheries. 131 pp. Smith, C. L. 1985. The inland fishes of New York state. New York State Department of Environmental Conservation, Albany, NY. 522 pp. Trautman, M. B. 1981. The fishes of Ohio. Ohio State University Press, Columbus, OH. Revision Date: 1/28/2013 Peer Review Date: 4/1/2016 Fuller, P., 2018, Fundulus heteroclitus (Linnaeus, 1766): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=688, Revision Date: 1/28/2013, Peer Review Date: 4/1/2016, Access Date: 7/21/2018 This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.	<urn:uuid:bed298ad-373d-45b6-8c18-077aea1b93a9>	2.84375	860	Structured Data	Science & Tech.	56.960981	95,577,661
Species Detail - Common Garden Snail (Cornu aspersum) - Species information displayed is based on all datasets. Terrestrial Map - 10kmDistribution of the number of records recorded within each 10km grid square (ITM). Marine Map - 50kmDistribution of the number of records recorded within each 50km grid square (WGS84). Common Garden Snail Invasive Species: Invasive Species \|\| Invasive Species: Invasive Species >> Medium Impact Invasive Species (O. F. Müller, 1774) 2 January (recorded in 1974) 28 December (recorded in 1999) National Biodiversity Data Centre, Ireland, Common Garden Snail (Cornu aspersum), accessed 22 July 2018, <https://maps.biodiversityireland.ie/Species/123848>	<urn:uuid:af8f82a6-b125-4cdc-ad3e-98baf3a60566>	2.828125	177	Structured Data	Science & Tech.	35.705	95,577,672
Hydro reservoirs produce less CO2 than believed Hydroelectric reservoirs emit fewer greenhouse gases than the amount previously attributed to them, says an international team of scientists. Reservoirs used to generate hydroelectric power emit 48 million metric tonnes of carbon annually, according to a new study of 85 reservoirs published in this week's online version of Nature Geoscience. That is very small compared to a previous estimate of emissions from all man-made reservoirs, including hydroelectric reservoirs, of 321 million metric tonnes. "Our analysis indicates that hydroelectric reservoirs are not major contributors to the greenhouse gas problem," Jonathan Cole, a limnologist at New York State's Cary Institute of Ecosystem Studies, said in a release. "But there are some caveats," he warned. "To date, only 17 per cent of potential hydroelectric reservoir sites have been exploited, and impacts vary based on reservoir age, , and location." In particular, emissions are correlated with latitude and the amount of vegetation being flooded. "Reservoirs in tropical locations, such as the Amazon, emit more methane and carbon throughout their life cycles," said lead author Nathan Barros of the Federal University of Juiz de Fora in Brazil. Hydro reservoirs are created by damming rivers and flooding large swaths of land so that when water is released it can turn turbines and generate electricity. The water not only displaces wildlife and people, but drowned vegetation and soil also give off the greenhouse gases carbon dioxide and methane. As reservoirs age, emissions decline, with cold-water systems giving off fewer emissions than warm water ones. Hydroelectricity supplies an estimated 20 per cent of the world's electricity and accounts for more than 85 per cent of electricity from renewable sources. - Greenhouse gas emissions from hydroelectric dams are not one sixth of the previous scientific estimate, as originally reported, since that prior estimate of 321 metric tonnes included non-hydroelectric man-made reservoirs. The new study looked only at hydroelectric dams. However, the new study indicates that the hydroelectric-related emissions are indeed lower than scientists had expected. Aug 09, 2011 8:50 AM ET	<urn:uuid:595e693d-55e6-4543-847a-62d1cf31a65f>	3.734375	441	News Article	Science & Tech.	22.291119	95,577,684
See the image below for the complete question: content copied here: 1. A square loop with sides of length L has total resistance R and mass m. It is falling under a constant gravitational force directed down along the -y direction. The magnetic field varies linearly with height y: and is directed out of the page along the z direction. Denote the center of the loop as y0(t) and its speed a) What is the magnetic flux Φ through the loop as a function of the y-coordinate of the loop? HINT: Because the field varies linearly the flux is just the area times the value of at the center of the loop. b) What is the magnitude of the induced emf if the loop is falling at speed v? c) Is the induced current clockwise or counter-clockwise if the ring is falling? You may use Lenz's law. d) From the magnitude of the current find the force from the constant field B on each side of the loop (top, bottom, left and right) as a function of the center of the loop y0 and the speed v. e) The loop will eventually fall at a constant speed vo. Calculate ???????? by balancing the total force on the loop and the gravitational force. f) What is the rate of work done by the current flowing through the resistance at this speed? Show that this is equal to the rate of work done by gravity. Recently Asked Questions - What is the hardcore communist government in North Korea like? - Please refer to the attachment to answer this question. This question was created from Unit II Assessment. - The annual salaries of General Managers of all 220 locations of a large national grocery chain were published in a recent financial publication. Included in	<urn:uuid:8cde19f2-8fd9-4087-8783-0775a1056be6>	3.1875	368	Q&A Forum	Science & Tech.	70.292396	95,577,689
Vbscript On Error Resume Reply Alex French says: December 11, 2007 at 3:38 am This is probably the best explanation I've seen so far. Before statement: x = 1/0 Before statement: y = CInt(777777) Before statement: z = 1 + "2nd" End of test A runtime error has occurred: Err.Number = 13 Err.Description = Type Error Handling and Debugging 5. I completely understand the whole thing now! Check This Out Herong Yang VBScript Tutorials - Herong's Tutorial Examples - Version 5.23, by Dr. MsgBox "Error # " & CStr(Err.Number) & " " & Err.Description Err.Clear ' Clear the error. Previous Page Print PDF Next Page Advertisements Write for us FAQ's Helping Contact Table of Contents About This Book Introduction of VBScript - Visual Basic Scripting Edition Variant Data Type, Subtypes, and Literals Arithmetic Operations Numeric Comparison Operations and Logical Operations String Operations - You can use the condition of (Err.Number>0) to determine a runtime error has occurred or not. Vbscript On Error Exit Once the error handling flag is turned on, execution will not be stopped when a runtime error occurs. Syntax On Error resume next - Enable error handling On Error goto 0 - Disable error handling Error properties: err.Number (default) err.Source err.Description Examples In the examples below - replace the Its syntax is: where ErrorNumber is the numeric code for the error you’d like to generate. - Is there a way to load the ShowConfig before Sitecore finishes initializing? - Reply Follow UsPopular TagsC# Scripting JScript VBScript Language Design COM Programming Rarefied Heights Puzzles Rants Performance Security C# 4.0 Non-computer SimpleScript JScript .NET Immutability Code Quality Pages Recursion Books Archives November - Produce Dürer's magic square Output a googol copies of a string is /dev/sdxx the kernels representation of the physical filesystems? (strictly talking to the device drivers) or the logical filesystems? - The problem with this is that when an error is generated, the user is unaware of it; the only indication that an error has occurred is the blank Alert box (from - You can only enable error handling in VBScript by using the On Error Resume Next syntax. - The primary limitation is due to the limited functionality of the On Error statement in VBScript. - When the third runtime error occurred on statement, z = 1 + "2nd", execution continued again because the error handling flag was turned on. - MsgBox "Error # " & CStr(Err.Number) & " " & Err.Description Err.Clear ' Clear the error. - The main point here is that error handling using On Error and the Err object puts you in control of errors, rather than allowing an error to take control of the - Example On Error Resume Next DoStep1 If Err.Number <> 0 Then WScript.Echo "Error in DoStep1: " & Err.Description Err.Clear End If DoStep2 If Err.Number <> 0 Then WScript.Echo "Error in DoStop2:" How to report trailhead bugs When I added a resistor to a set of christmas lights where I cut off bulbs, it gets hot. Figure 4.6, for instance, shows the Alert box that is displayed when the user enters a value of 13 into the text box.Example 4-10. Calling the Err.Raise Method Learning resources Microsoft Virtual Academy Channel 9 MSDN Magazine Community Forums Blogs Codeplex Support Self support Programs BizSpark (for startups) Microsoft Imagine (for students) United States (English) Newsletter Privacy & cookies On Error Resume Next Vbscript W3schools What does it do? As you can see from the previous section, my last VBScript example reported the last runtime error, not the first one. http://stackoverflow.com/questions/2202869/what-does-the-on-error-resume-next-statement-do Discover unlimited learning on demand for around $1/day. Thanks Regards Jayasimha Reply Kunals says: February 12, 2008 at 3:00 am Nice work helps a lot in understanding. Vbscript Err Object Reply Richard Trollson says: November 11, 2010 at 11:17 am But I want to hear more about the Peloponnesian war…. Visual Basic? RequirementsVersion 1See AlsoErr Object (VBScript)Exit StatementVBScript Run-time ErrorsVBScript Syntax Errors Show: Inherited Protected Print Export (0) Print Export (0) Share IN THIS ARTICLE Is this page helpful? On Error Resume Next Vbscript W3schools Here is the modified VBScript example to catch the first runtime error in a section of code: Solutions? You can then decide what to do about the error —you can, for instance, continue execution regardless of the error, or you can halt execution of the program. http://itechnologysolutionsllc.com/on-error/vbscript-on-error-resume-next-example.php Line 12 is a perfectly valid assignment statement that always executes without error, but the Err.Number property still contains the error number from the previous error in line 5. Is this possible? On Error Resume Next Example It sets the values of Err.Number to and the Err object’s Source and Description properties to a null string. A more complete version of the syntax of the Raise method REM More VB Code... In addition, the primary use of the Source property is to signal an error that is generated by some other object, like an OLE automation server (like Microsoft Excel or Microsoft You can not catch those errors, because it depends on your business requirement what type of logic you want to put in your program. But as we'll see, there are some subtleties. The host can sometimes opt to handle such errors differently. Vbscript On Error Resume Next Scope Programming Outlook Forms 7. This documentation is archived and is not being maintained. The caller sees the error, but the caller is in ‘resume next' mode, so it resumes. Reply Jimbo says: September 7, 2010 at 4:09 am Thankyou! navigate here Reply Jayasimha says: January 18, 2008 at 12:12 pm Hi, Very good explanation. In some cases, the script debugger may be invoked at the point of the error. Do they have the same semantics? more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed Too bad I guess... –apandit Oct 1 '08 at 15:12 2 You could change WScript.Echo within the If statement to call a Function or Sub, which could in turn exit Sometimes, the On Error follows the Goto label to alter the flow of execution, something like this in a Sub code block, now you know why and how the usage of e.g. Reply firstname.lastname@example.org says: September 14, 2011 at 6:48 am Hi - Two questions: 1) If you turn "On Error Resume Next" on within a function or subroutine, does it only be The best content for your career. As a developer, if we want to capture the error, then Error Object is used.	<urn:uuid:0d97014c-1eaa-4ab2-ab0e-dc273031bb0e>	2.765625	1,599	Q&A Forum	Software Dev.	56.324978	95,577,700
Scientists create hybrid embryos from near extinct northern white rhino LONDON: Scientists have given life to hybrid embryos from the sperm of near-extinct northern white rhinoceroses in the laboratory, hoping that they can ultimately help in saving the species. The northern white rhino is the world's most endangered mammal, and its only two living members are a mother and daughter, living in Kenya's Ol Pejeta Conservancy. Scientists did, however, managed to collect around 300 millilitres of semen from the last four bull rhinos, which is said to be a large quantity, albeit too low-quality for insemination.Having used some of this to fertilise eggs in vitro from the closest relative - the southern white rhino - they hope to use the same techniques to create an embryo of a pure northern white rhino with eggs harvested from the two females. This could then be implanted into a surrogate to gestate. "Within three years we hope to have the first (northern white) rhino calf born," said Thomas Hildebrandt of Germany's Leibniz Institute for Zoo and Wildlife Research. The findings were later published in the journal by Nature Communications on Wednesday. The low-grade sperm have to be activated with a lab culture so that they can be used in an IVF technique known as intracytoplasmic injection. The hybrid embryos have developed enough for implantation, and have now been frozen while scientists look for potential surrogate southern white rhino females to carry them to term. "Many people working in the conservation area are very against using biotechnology," Hildebrant said. He argued that using biotechnology was not unnatural, and would simply correct a change in the ecosystem caused by humans by the hunting of rhinos. "The northern white rhino did not fail evolution, it failed because it was not bullet-proof. It was slaughtered, it caused a disbalance in the ecosystem ... and we have the tools in our hands to correct that." He said.	<urn:uuid:84bfb3f9-c387-4df9-896c-e1c9825e3651>	3.1875	417	News Article	Science & Tech.	40.484739	95,577,704
T or F 1.Temperature is a measure of the random motion of atoms and molecules. 2.In nature, light is produced by accelerating charged particles and by electrons engaging in quantum jumps. 3.Reddish stars have hotter surface temperatures compared to bluish stars. 4.Helium has an atomic number of 2 which indicates that a neutral atom of helium-4 contains 4 electrons. 5.Changing the number of neutrons inside an atom will change one element into another element. 6.Two molecules of the element hydrogen are needed to make one atom of the compound water. 7.Cool stars tend to form molecules by allowing atoms to share electrons with each other.	<urn:uuid:7f21dfa7-6522-4f1a-8e2a-dd97091490e3>	3.75	140	Listicle	Science & Tech.	54.897367	95,577,710
Mathematics And Computer mathematics and computer Thesis: At first glance, although the connection obviously does not seem between mathematics and computer technology , mathematics provides computers to work with an optimum rate, mathematics arranges the operational system of computers and mathematical problems which its solving is very hard for a person can be solved with computers. I. Mathematics affects on working with an optimum rate of computers. A. Discrete mathematics arranges using necessary figures in software. 1. Using only necessary figures makes computers fast (Denvir, 1986, p. VII). 2. Not using unnecessary figures makes hard disc convenient. B. In addition, discrete mathematics arranges suitable structure in software. C. Algorithm in discrete mathematics provides integrity of computer programs. Okunma: 1103 - Yorum: 0 - Amp	<urn:uuid:0526fc6d-d651-49d0-b1d5-023e7f67a435>	3.296875	175	Comment Section	Science & Tech.	22.569938	95,577,735
The oceans are in a worse state than previously suspected, according to an expert panel of scientists. In a new report, they warn that ocean life is "at high risk of entering a phase of extinction of marine species unprecedented in human history". They conclude that issues such as over-fishing, pollution and climate change are acting together in ways that have not previously been recognised. The impacts, they say, are already affecting humanity. "The rate of change is vastly exceeding what we were expecting even a couple of years ago," said Ove Hoegh-Guldberg, a coral specialist from the University of Queensland in Australia. Some species are already fished way beyond their limits - and may also be affected by other threats" But more worrying than this, the team noted, are the ways in which different issues act synergistically to increase threats to marine life. Some pollutants, for example, stick to the surfaces of tiny plastic particles that are now found in the ocean bed. This increases the amounts of these pollutants that are consumed by bottom-feeding fish. Plastic particles also assist the transport of algae from place to place, increasing the occurrence of toxic algal blooms - which are also cause d by the influx of nutrient-rich pollution from agricultural land. "What we're seeing at the moment is unprecedented in the fossil record - the environmental changes are much more rapid," Professor Rogers told BBC News. "We've still got most of the world's biodiversity, but the actual rate of extinction is much higher [than in past events] - and what we face is certainly a globally significant extinction event." (1) There is an assumption which seems to come from James Lovelock that the Earth has various homoeostatic mechanisms which will cause any imbalance to rectify itself over time. Lovelock seems to have devoted considerable amount of time to his Gaia hypothesis in which he attempted to explain the strange circumstances in which the Earth of all the solar planets seemed admirably suited for life. I founded noteworthy that his book had little or no mention of Darwin or natural selection. He seems to have taken the longevity of life on Earth as indicating some kind of balancing mechanism which insures that life continues on our planet. Twenty-six years ago when I first started writing this book, I had no clear idea of what Gaia was although I had thought deeply about her. What I did know was that the Earth was different from Mars and Venus. It was a planet with apparently the strange property of keeping itself always a fit and comfortable place for living things to inhabit. I had the idea that somehow this property was not an accident of its position in the Solar System but was a consequence of life on its surface. Now twenty-six years on, I know her better and see that in this first book I made mistakes. Some were serious, such as the idea that the Earth was kept comfortable by and for its inhabitants, the living organisms. I failed to make clear that it was not the biosphere alone that did the regulating but the whole thing, life, the air, the oceans, and the rocks. The entire surface of the Earth including life is a self-regulating entity and this is what I mean by Gaia. (2) This is presented in a very anthropomorphic terminology and while Lovelock has said that these statements are poetic ways of expressing scientific truth, I think that it is more the case that he is creating a kind of scientific pantheism which eschews the notion of deity that brings it in by the back door. Gaia would have to learn by trial and error the art of controlling its environment, at first within broad bounds and later, as control was refined, by maintaining it near the optimum state for life.(2) What has this to do with this news story? The answer is that there seems to be a certain body of opinion which draws upon Lovelock's thesis or even takes an explicitly religious rationale for purpose in creation (and with similar homeostatic mechanism, but as part of God's purpose). For Lovelock's Earth has a purpose -- to maintain life upon its surface. The danger with this kind of thinking is the assumption that while the oceans are in a bad way, if we keep them alone, or can reduce our activity, they will automatically restore themselves to a kind of steady state. But the history of extinctions and the destruction of even small habitats such as a forest by fire demonstrate that this is not the case. What happens in these cases is that an ecological niche has been vacated by extinct species and that other species or near relatives take advantage of the niche after the destructive effect has ended. For example, after a fire, seeds will blow across the burnt soil and take root, and fauna will follow -- but the situation will not be identical to that which took place before, although it may superficially resemble it. What was found was that where natural forces had destroyed or damaged complex ecosystems, such as flood, fire, hurricane etc, that far from "the balance of nature" reasserting itself, that a completely different ecosystem would come into being, with different outcomes from that observed before in terms of fauna and flora and their interactions. But with the oceans, and the destructive effects of pollution, acidification, and overfishing, the time period for the destructive effects to have ended will be considerably greater than that of a mere forest fire. We may be talking about geological timescales. The cod stocks after all, still show no sign of recovery in the West Atlantic, and the collapse of cod stocks after overfishing is a small-scale disaster compared to the catastrophe that our confronts us. The fate of the western cod stocks is well known. Increased fishing and decreasing spawning stock sizes resulted in overfishing and a biological collapse. The fishery for the major cod stocks in the western Atlantic was closed in 1992. (3) The homoeostatic scenario is a kind of pseudoscientific wishful thinking which may prevent us from taking adequate steps to prevent a global ecological disaster within the oceans. If Lovelock had read Darwin more carefully, he might have realised that there is no reason why most forms of life, apart from perhaps bacteria, might not become extinct. The Earth is not sentient, and we project human desires upon the planet at our peril. In the end, of course, all life on Earth will become extinct. But in the meantime, we can make a difference and postpone, if we are lucky and take sufficient action, that final day. Inevitabilities should never be depressing. An old philosophical tradition, dating at least to Spinoza, proclaims that freedom is the recognition of necessity. If we respect intellect, true freedom must come from learning the ways of the world-what can be changed and what cannot-and by shaping a gutsy life accordingly. (Stephen Jay Gould) (4) Part of this can be done with fishing quotas, as long as these are implemented fairly. But the history of quota fishing is not a good one -- there are a number of dodges which have been used by the fishermen of some countries where the governments cheerfully turn a blind eye to the practice. It is the spirit of the quota which matters and keeping technically within the limits while finding ways of overfishing in other jurisdictions requires international rather than national agreements. Moreover, it is this kind of shady practice which led to the rise of piracy in Somalia and elsewhere, and while that is now fueled more by greed for easy pickings, it might never have begun and spread so rapidly if it had not been for the resentment of native fishermen in seeing European trawlers coming in and consuming fish stocks in bulk, leaving little for the subsistence fishing of the native population. One thing is sure, and that is that the era of cheap fish will be drawing to a close one way or the other. Either we will have to regulate our consumer driven overfishing and pollution of the oceans, or evolutionary mechanisms will do it for us as we wipe out the bulk of the planet's fish, and create an ocean too polluted and acidified to sustain any restoration of marine species. (2) Gaia: A New Look at Life on Earth, James Lovelock, Preface to 2000 edition (4) Hen's Teeth and Horse's Toes., Stephen Jay Gould Teenage takeover - I am a trident student that has been observing lessons and attending evening classes but working at the l'Office de Jèrriais and today we were all at the... 4 hours ago	<urn:uuid:a0ef291e-19ab-49d2-8141-52a774c3c505>	3.375	1,751	Personal Blog	Science & Tech.	40.811373	95,577,755
John H. Seinfeld Dual Affiliation with Division of Engineering and Applied Science Assistant: Martha Hepworth Increases in the levels of greenhouse gases, such as carbon dioxide, and airborne particulate matter, aerosols, are impacting the Earth's climate. Understanding the chemical and physical processes that govern the dynamics and distribution of gases and aerosols in the atmosphere and their effects on climate and air quality represents one of the grand challenges of science in the 21st Century. That the increase of greenhouse gases attributable to human activities is causing a steady rise in the Earth's global mean temperature is unequivocal. The ability to forecast future climate based on scenarios of energy consumption and other activities is hampered by uncertainties in two major climate factors. Aerosols, on the whole, partially offset the global warming due to the increase of greenhouse gases, but the complex life cycle of aerosols in the atmosphere is still incompletely understood. This uncertainty translates into an uncertainty of the effect of aerosols on climate. Second, clouds are a large source of uncertainty in climate models, and the most uncertain aspect is the extent to which changes in aerosol levels have influenced cloud amounts and precipitation and will do so in the future. Our research is broadly aimed at improving our understanding of the physics and chemistry of atmospheric aerosols, at scales ranging from the urban to the global atmosphere. This improved understanding will lead to more accurate representations of these processes in urban, regional, and global atmospheric models. We focus on the fundamental processes of aerosol formation and growth in the atmosphere. Of these, both the most important and the most uncertain are those involving the organic fraction of the atmospheric aerosol, which can be as large as 90% in some regions. Aerosol formation and evolution processes involve detailed gas-phase atmospheric chemistry and gas-particle interactions. The interaction of aerosols with atmospheric water is key to much of their behavior. We also focus on developing and evaluating the representation of aerosol-cloud-precipitation interactions in atmospheric models. Our research is broadly divided into three strongly overlapping areas: - Laboratory chamber studies of the formation and evolution of atmospheric organic aerosols. - Airborne field measurement of atmospheric aerosols and clouds. - Urban, regional, and global modeling of air quality and climate.	<urn:uuid:242328c7-10ad-4164-bbd0-65661025974c>	3.03125	461	About (Org.)	Science & Tech.	16.816975	95,577,770
Blooming heck! The 120-mile stretch of algae so big it can be seen from SPACE - 'Remarkable' bloom caused by iron in snow blown across from Antarctica - Mammoth growth is 'largest in living memory', say scientists - Algae has sparked a feeding frenzy for surrounding sea life A bright green bloom of algae 120 miles long and 60 miles wide is so big it can be seen from space. The 'remarkable' bloom has been caught on a satellite camera based 400 miles above Earth. It is thought to have occurred when snow was blown into the ocean from Antarctica. The mammoth growth was probably caused by a build-up of iron which came from the snow falling into the waters, according to Australian scientists who spotted the bloom on satellite images. 'Remarkable': The blooms of bright green algae floating in ocean waters off Antarctica are so large they can be seen from space Phenomenon: The images were captured from the Modis instrument on Nasa's Terra satellite, located at least 400 miles from Earth They say the phenomenon could be the largest growth in living memory and it has caused a feeding frenzy for the surrounding sea life. Krill and plankton are feasting on the algae and, in turn, they are being eaten by larger predators such as whales, penguins and seals, it has been reported. According to the Telegraph, scientists say Antarctica's snow, which contains small concentrations of iron, were blown into the sea by strong winds in the region over the summer. Dr Mark Curran, from the Australian Antarctic Division, told ABC Radio: 'Very, very tiny amounts of iron act as a nutrient. 'Usually algae in this region are iron limited and so when they get a small amount of iron and they have everything else they need, that's enough for them to bloom. 'They die off, things like bacteria comes through there and feeds on the material and then the material eventually will sink to the bottom of the ocean - anything that hasn't been consumed by predators higher up the food chain.' Blown away: The algae is thought to have occurred after high winds pushed snow into the ocean from Antarctica (pictured) In bloom: Tiny amounts of iron act as a nutrient which allows algae to form and thrive Feeding frenzy: Penguins and seals are just a few of the sea life feasting in the area thanks to the algae The images were captured from the Modis instrument on Nasa's Terra satellite, located at least 400 miles from Earth. This particular bloom of algae has been floating on the ocean's surface for three weeks but it is likely to disappear soon, with the parts that haven't been eaten breaking down naturally without any negative impact on the environment. Describing the phenomenon as a 'remarkable natural event', scientist Dr Jan Leiser, told The Conversation website: 'Iron is the limiting nutrient in that part of the world, so as soon as you have iron and as soon as you have sunlight and all the other conditions are right, then these algal blooms will quite happily grow and reproduce. 'Where the iron is coming from we're not quite sure. One idea is that it's been taken off the continent by strong offshore winds that take snow and sediment load in the snow into the ocean surface, and the snow melts there and releases the nutrient load.' Most watched News videos - Shocking video shows mother brutally beating her twin girls - Drone footage shows missing Scottish climber in the Himalayas - Waitress tackles male customer after grabbing her backside - Sir David Attenborough shuts down Naga Munchetty's questions - Road rage brawl ends with BMW driver sending man flying - Bon Jovi star Richie Sambora soars in fighter plane - Man sets up projector to make garden look like jurassic park - Disaster averted by good samaritan that saved child in hot car - Cohen taped Trump discussing payment to Playboy model - Prince George turns five: His memorable moments - Woman livestreams unassisted birth of her 6th child in her garden - Man fatally shoots a father during an argument over a handicap spot	<urn:uuid:0040a448-6f2b-48a1-85c9-56b3b0120422>	3.1875	851	News Article	Science & Tech.	29.549615	95,577,784
Norcross, Brenda L.; Holladay, Brenda A.; Busby, Morgan S.; Mier, Kathryn L. A multidisciplinary research cruise was conducted in the Chukchi Sea in summer 2004 during which we investigated assemblages of small demersal fishes and ichthyoplankton and the water masses associated with these assemblages. This study establishes a baseline of 30 demersal fish and 25 ichthyoplankton taxa in US and Russian waters of the Chukchi Sea. Presence/absence of small demersal fish clustered into four assemblages: Coastal Fishes, Western Chukchi Fishes, South Central Chukchi Fishes, and North Central Chukchi Fishes. Habitats occupied by small demersal fishes were characterized by sediment type, bottom salinity, and bottom temperature. Abundance of ichthyoplankton grouped into three assemblages with geographical extent similar to that of the bottom assemblages, except that there was a single assemblage for Central Chukchi Fishes. Water-column temperature and salinity characterized ichthyoplankton habitats. Three water masses, Alaska Coastal Water, Bering Sea Water, and Winter Water, were identified from both bottom and depth-averaged water-column temperature and salinity. A fourth water mass, Resident Chukchi Water, was identified only in the bottom water. The water mass and habitat characteristics with which demersal and larval fish assemblages were associated create a baseline to measure anticipated effects of climate change that are expected to be most severe at high latitudes. Monitoring fish assemblages could be a tool for assessing the effects of climate change. Climate-induced changes in distributions of species would result in a restructuring of fish assemblages in the Chukchi Sea. Ben M Fitzpatrick Full Text Available The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304 collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth, down the fore reef slope to the reef base (10-30 m depth then across the adjacent continental shelf (30-110 m depth. Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of Jacob, W.; McClatchie, S.; Probert, P. K.; Hurst, R. J. We examined the relationship between demersal fish assemblage and depth, temperature, latitude and longitude off southern New Zealand (46-54°S and 165-180°E) in water depths of 80-787 m. Catch weight data were analysed by two-way indicator analysis (TWIA), groupaverage agglomerative clustering (UPGMA) and Detrended Correspondence Analysis (DCA). The spatial pattern of demersal fish off southern New Zealand conforms to the concept of species groups or fish assemblages related to environmental gradients. Shallow-water assemblages were dominated by species from the families Gempylidae, Squalidae, Triakidae and Moridae, mainly represented by Thyrsites atun, Squalus acanthias, Galeorhinus australis, and Pseudophycis bachus. Deep water assemblages were dominated by Chimaeridae, Argentinidae, Merlucciidae and Macrouridae, mainly represented by Hydrolagus novaezelandiae, Argentina elongata, Macruronus novaezelandiae, and Lepidorhynchus denticulatus. Total catch weight was often dominated by Merlucciidae, Macrouridae and Gempylidae. Fish assemblages were related to discrete ranges of depth (300 m) and temperature (9.5°C), but the range of sediment types was too narrow to show any correlation. Quattrini, Andrea M.; Demopoulos, Amanda W. J.; Singer, Randal; Roa-Varon, Adela; Chaytor, Jason D. Recent investigations of demersal fish communities in deepwater (>50 m) habitats have considerably increased our knowledge of the factors that influence the assemblage structure of fishes across mesophotic to deep-sea depths. While different habitat types influence deepwater fish distribution, whether different types of rugged seafloor features provide functionally equivalent habitat for fishes is poorly understood. In the northeastern Caribbean, different types of rugged features (e.g., seamounts, banks, canyons) punctuate insular margins, and thus create a remarkable setting in which to compare demersal fish communities across various features. Concurrently, several water masses are vertically layered in the water column, creating strong stratification layers corresponding to specific abiotic conditions. In this study, we examined differences among fish assemblages across different features (e.g., seamount, canyon, bank/ridge) and water masses at depths ranging from 98 to 4060 m in the northeastern Caribbean. We conducted 26 remotely operated vehicle dives across 18 sites, identifying 156 species of which 42% of had not been previously recorded from particular depths or localities in the region. While rarefaction curves indicated fewer species at seamounts than at other features in the NE Caribbean, assemblage structure was similar among the different types of features. Thus, similar to seamount studies in other regions, seamounts in the Anegada Passage do not harbor distinct communities from other types of rugged features. Species assemblages, however, differed among depths, with zonation generally corresponding to water mass boundaries in the region. High species turnover occurred at depths <1200 m, and may be driven by changes in water mass characteristics including temperature (4.8-24.4 °C) and dissolved oxygen (2.2-9.5 mg per l). Our study suggests the importance of water masses in influencing community structure of benthic fauna, while considerably adding Open Access DOWNLOAD FULL TEXT ... In this study, we analysed data from scientific trawl surveys carried out on the ... Keywords: biodiversity, ecosystem indicators, fishing impact, historical data, marine ecology, trawling surveys ... Full Text Available Seasonal experimental trawl surveys were carried out in the Northern Aegean and Thracian seas (NE Mediterranean, Greece, from summer 1990 to autumn 1993, during which a total of 172 fish species were caught. In these areas, fishing pressure is very high, since approximately 50% of the Greek otter trawl fleet operates there, producing more than 57% of the total demersal landings. Different statistics were used to assess spatial structure, seasonal changes and diversity of the demersal fish assemblages on the continental shelf and upper slope. The following measures were applied to the species abundance matrix: species diversity, species richness, evenness and dominance. The analysis of 501 bottom trawls revealed that, in general, species diversity, richness and evenness decreased with water depth, with the highest values at depths 200 m. The effect of depth on the diversity patterns observed was always significant, while seasonal trends were similar with those described for the overall diversity characteristics in each area. Classification and ordination methods showed the existence of 4 groups associated with the continental shelf and upper slope in each area. Classification of the top ranking species at each group and area revealed that commercially important species were dominant in the shallowest zone ( Hofstede, ter R.; Rijnsdorp, A.D. Fish communities are dynamic and their structure is known to change over time. Traditionally, these changes were considered to be fisheries-induced, but recent analyses also suggest that global warming could affect the distribution, abundance, and assemblage composition of marine fish. However, Emma V Sheehan Full Text Available Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km(2 of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls were sampled to test a recovery hypothesis that was defined as 'the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls'. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus. While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries. Sheehan, Emma V; Stevens, Timothy F; Gall, Sarah C; Cousens, Sophie L; Attrill, Martin J Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km(2) of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as 'the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls'. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries. Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n3p153 Estuarine demersal fish assemblage from a transition region between the tropics and the subtropics of the South Atlantic. The coastal state of Espírito Santo is in the central region of Brazil, where biological productivity is considered low. The objective of this work is to present a current list of demersal, estuarine fish from northern Espírito Santo. This work is based on the compilation of data collected monthly using trawl nets. The ichthyofauna comprises 57 species, within 10 orders and 32 families. The family Sciaenidae has the largest number of species (8, followed by Carangidae (4 and Gerreidae (4. This coincides with what has been found for the Brazilian coast and for the coast of the South Atlantic. It is important to note that the total species richness in the estuaries of northern Espírito Santo is lower than other estuaries of the South West Atlantic coast. Most of the species are widely distributed in the Western Atlantic. Only a small part (14% of the fauna of northern Espírito Santo was evaluated in regards to risk of extinction, but conservation should be prioritized in the area due to overexploitation of species. Farré, Marc; Tuset, Víctor M.; Cartes, Joan E.; Massutí, Enric; Lombarte, Antoni The morphological and functional traits of fishes are key factors defining the ecological and biological habits of species within ecosystems. However, little is known about how the depth gradient affects these factors. In the present study, several demersal fish assemblages from the Balearic Islands (western Mediterranean Sea) along a wide depth range (40-2200 m) were morphologically, functionally and ecologically described. The morphological characterization of communities was performed using geometric morphometric methods, while the functional structures were obtained by the functional categorization of species and the application of principal coordinates analysis (PCoA). The results revealed that morphospaces presented less richness of body forms as depth increases, although they showed a progressive spreading of species toward the periphery, with a proliferation of more extreme body traits, demonstrating lower morphological redundancy. In addition, a trend toward the elongation of body shape was also observed with depth. Moreover, functional diversity increased with bathymetry up to 1400 m, where it sharply decreased downwards. This decrease was parallel to a progressive fall of H‧ (ecological diversity) up to 2200 m. Functional redundancy progressively decreased until the deepest assemblage (more constantly in the deeper levels), which was almost exclusively dominated by benthopelagic wandering species feeding on suprabenthos. Redundancy analysis (RDA) demonstrated that both morphological and functional spaces showed high variation along the bathymetric range. Mantel test indicated that the majority of species presented similar spatial distribution within the morphospace and functional space, although in the functional space the more abundant species were always located at the periphery. These results demonstrate that the assessment of the morpho-functional variation between marine communities helps to understand the processes that affect the structure and Quiroga, Eduardo; Sellanes, Javier; Arntz, Wolf E.; Gerdes, Dieter; Gallardo, Victor A.; Hebbeln, Dierk Benthic megafaunal and demersal fish assemblages were sampled in three areas off Chile during the German-Chilean Expedition PUCK (SO-156) onboard the R/V Sonne from March to May 2001, at depths ranging from 120 to 2201 m. These samples, taken with an Agassiz trawl, are among the deepest ever taken in Chilean waters. A total of 147 species were recorded, mainly decapod crustaceans (Galatheidae, Pandalidae, Crangonidae), gastropods (Trochidae, Muricidae, Volutidae), ophiuroids (Asteronychidae, Gorgonocephalidae, Ophiolepididae, Ophiurinae), asteroids (Pterasteridae, Solasteridae, Goniopectinidae), polychaetes (Onuphidae, Aphroditidae, Maldanidae), and demersal fish (Macrouridae, Ipnopidae, Squalidae). Species richness and rarefaction analyses suggest that the fauna was undersampled. From the 147 species identified in this study, 36 species (24.5%) occurred only once and another 24 species occurred only twice (16.3%). Depth and dissolved oxygen levels were found to be the main factors influencing megafaunal changes along the continental shelf and in bathyal areas, as indicated by principal component and Pearson's correlation analyses. Some species appear to be limited to distinct areas in the upper and lower bathyal zones, whereas other species have a wider range, extending from the continental shelf to lower bathyal zones. Biogeographic relations exist with the Pacific, South Atlantic, and Southern Oceans, but the latter seem to be weaker than would be expected considering the connection by Antarctic intermediate water. Full Text Available The coastal state of Espírito Santo is in the central region of Brazil, where biological productivity is considered low. The objective of this work is to present a current list of demersal, estuarine fish from northern Espírito Santo. This work is based on the compilation of data collected monthly using trawl nets. The ichthyofauna comprises 57 species, within 10 orders and 32 families. The family Sciaenidae has the largest number of species (8, followed by Carangidae (4 and Gerreidae (4. This coincides with what has been found for the Brazilian coast and for the coast of the South Atlantic. It is important to note that the total species richness in the estuaries of northern Espírito Santo is lower than other estuaries of the South West Atlantic coast. Most of the species are widely distributed in the Western Atlantic. Only a small part (14% of the fauna of northern Espírito Santo was evaluated in regards to risk of extinction, but conservation should be prioritized in the area due to overexploitation of species. McGarvey, Daniel J.; Falke, Jeffrey A.; Li, Hiram W.; Li, Judith; Hauer, F. Richard; Lamberti, G.A. Methods to sample fishes in stream ecosystems and to analyze the raw data, focusing primarily on assemblage-level (all fish species combined) analyses, are presented in this chapter. We begin with guidance on sample site selection, permitting for fish collection, and information-gathering steps to be completed prior to conducting fieldwork. Basic sampling methods (visual surveying, electrofishing, and seining) are presented with specific instructions for estimating population sizes via visual, capture-recapture, and depletion surveys, in addition to new guidance on environmental DNA (eDNA) methods. Steps to process fish specimens in the field including the use of anesthesia and preservation of whole specimens or tissue samples (for genetic or stable isotope analysis) are also presented. Data analysis methods include characterization of size-structure within populations, estimation of species richness and diversity, and application of fish functional traits. We conclude with three advanced topics in assemblage-level analysis: multidimensional scaling (MDS), ecological networks, and loop analysis. Full Text Available The analysis of 255 bottom trawl samples obtained in annual experimental surveys (2007–2010 along the western Mediterranean shows the existence of five well-defined demersal assemblages that follow a depth distribution: (a upper shelf assemblages, including two assemblages differentiated by the type of substrate (sand-muddy and terrigenous muddy bottoms; (b a middle shelf assemblage; (c an upper slope assemblage; (d a middle slope assemblage. Faunally, they are dominated by fish (37% of 452 total species, followed by crustaceans (22%, molluscs (17%, echinoderms (9%, and other invertebrates (15%. The assemblages identified showed major alterations on the shelf and shelf edge and less pronounced ones on the upper and middle slope. The average diversity values were more or less high, evidencing the high species richness in the western Mediterranean. The identified assemblages may facilitate future multispecies fisheries management based on an ecosystem approach. Firdaniza; Gusriani, N. As an archipelagic country, Indonesia has considerable potential fishery resources. One of the fish resources that has high economic value is demersal fish. Demersal fish is a fish with a habitat in the muddy seabed. Demersal fish scattered throughout the Indonesian seas. Demersal fish production in each Indonesia’s Fisheries Management Area (FMA) varies each year. In this paper we have discussed the Markov chain model for demersal fish yield analysis throughout all Indonesia’s Fisheries Management Area. Data of demersal fish catch in every FMA in 2005-2014 was obtained from Directorate of Capture Fisheries. From this data a transition probability matrix is determined by the number of transitions from the catch that lie below the median or above the median. The Markov chain model of demersal fish catch data was an ergodic Markov chain model, so that the limiting probability of the Markov chain model can be determined. The predictive value of demersal fishing yields was obtained by calculating the combination of limiting probability with average catch results below the median and above the median. The results showed that for 2018 and long-term demersal fishing results in most of FMA were below the median value. Peter J. Auster Full Text Available Pelagic and demersal guilds of piscivorous fishes are linked by a variety of biological and physical processes that mediate interactions with common prey species. Understanding the behaviors of predators and prey can provide insight into the conditions that make such linkages possible. Here we report on the behaviors of mid-water piscivorous fishes and the responses of prey that produce feeding opportunities for demersal piscivorous fishes associated with "live bottom" ledge habitats off the coast of Georgia (northwest Atlantic Ocean. Prey taxa reduced nearest neighbor distances and retreated towards the seafloor during predatory attacks by mid-water fishes. Demersal fishes subsequently attacked and consumed prey in these ephemeral high density patches. No predation by demersal fishes was observed when prey species were at background densities. If the predator-prey interactions of demersal piscivorous fishes are commonly mediated by the predatory behavior of midwater piscivorous fishes and their prey, such indirect facilitative behaviors may be important in terms of the population processes (e.g., prey consumption and growth rates of these demersal fishes. Sobocinski, Kathryn L.; Ciannelli, Lorenzo; Wakefield, W. Waldo; Yergey, Matthew E.; Johnson-Colegrove, Angela The juvenile demersal fish assemblage along the Pacific Northwest coast has received little attention relative to adult life history stages since pioneering work in the 1970s. Increasing severity of hypoxia along the Oregon coast in recent years has prompted investigations into the response of biota in this region. We used summer data (2008-2013) from a beam trawl survey targeting juvenile demersal fishes in soft-bottom habitats along the Oregon coast to describe patterns of distribution and abundance at fixed sampling stations (from 30 m to 100 m depth). We relate the assemblage and abundance of the common species to environmental variables and analyze condition of recently settled fish (improve our understanding of this community, especially in light of changing environmental drivers such as decreasing pH, warming water, and episodic periods of low dissolved oxygen coinciding with settlement for many species. Full Text Available Malacca Strait is one of the main fishing areas for demersal fishery in Indonesia. To support the management of that fishery, an assessment of the demersal fish stock was conducted. This study estimated that the maximum sustainable yield and the optimal catch per unit effortof demersal fishery in the Malacca Strait were about 106.8 thousand tons/year and 28.5 tons per unit of Danish seine, respectively, resulting from the operation of 3,752 Danish seines. Unfortunately, fishing effort was higher than its optimum level and the fish stock was over-exploited since 2003. To recover the demersal fish stock to its optimum level and to ensure the optimal fish production from demersal fishery in the Malacca Strait, it was necessary to reduce fishing effort at about 67% from its level in 2011. Thomson, Russell J; Hill, Nicole A; Leaper, Rebecca; Ellis, Nick; Pitcher, C Roland; Barrett, Neville S; Edgar, Graham J To support coastal planning through improved understanding of patterns of biotic and abiotic surrogacy at broad scales, we used gradient forest modeling (GFM) to analyze and predict spatial patterns of compositional turnover of demersal fishes, macroinvertebrates, and macroalgae on shallow, temperate Australian reefs. Predictive models were first developed using environmental surrogates with estimates of prediction uncertainty, and then the efficacy of the three assemblages as biosurrogates for each other was assessed. Data from underwater visual surveys of subtidal rocky reefs were collected from the southeastern coastline of continental Australia (including South Australia and Victoria) and the northern coastline of Tasmania. These data were combined with 0.01 degree-resolution gridded environmental variables to develop statistical models of compositional turnover (beta diversity) using GFM. GFM extends the machine learning, ensemble tree-based method of random forests (RF), to allow the simultaneous modeling of multiple taxa. The models were used to generate predictions of compositional turnover for each of the three assemblages within unsurveyed areas across the 6600 km of coastline in the region of interest. The most important predictor for all three assemblages was variability in sea surface temperature (measured as standard deviation from measures taken interannually). Spatial predictions of compositional turnover within unsurveyed areas across the region of interest were remarkably congruent across the three taxa. However, the greatest uncertainty in these predictions varied in location among the different assemblages. Pairwise congruency comparisons of observed and predicted turnover among the three assemblages showed that invertebrate and macroalgal biodiversity were most similar, followed by fishes and macroalgae, and lastly fishes and invertebrate biodiversity, suggesting that of the three assemblages, macroalgae would make the best biosurrogate for Sangil, Carlos; Martín-García, Laura; Hernández, José Carlos; Concepción, Laura; Fernández, Raúl; Clemente, Sabrina The structure of demersal fish assemblages of commercial interest was studied at 51 sites on La Palma Island (Canary Islands, northeastern Atlantic). On this island, demersal fish populations are limited and independent from other islands. As deep water separates the islands and the shallow sublittoral platforms are not continuous, adult inter-island migrations are not possible except between the islands of Lanzarote and Fuerteventura. Otherwise, each island functions as a closed system, and the status of an island fish assemblage depends on local environmental conditions and activities performed in situ by the islanders. These circumstances provide a unique opportunity to test the intrainsular variability of fish assemblages. With this background, environmental parameters, fishing pressure and distance to the MPA were considered to identify the main factors explaining the spatial variation of fish assemblages off La Palma Island. Twenty-six fish species were recorded, but 60% of the total fish biomass was represented by only five species (Sparisoma cretense, Pomadasys incisus, Canthidermis sufflamen, Diplodus cervinus cervinus and Bodianus scrofa). However, the structure of assemblages was heterogeneous in response to different variables and showed substantial spatial variation. The assemblages were strongly modified by the presence of upright seaweed cover, fishing activities, and certain environmental variables. Differences were more pronounced in species that occupied the higher trophic levels. The most disturbed assemblages were those located in areas with lower upright seaweed cover and with higher fishing pressure, whereas the best-preserved assemblages corresponded to sites with controlled fishing activities, located within the MPA. de Jong, Maarten F.; Baptist, Martin J.; van Hal, Ralf; de Boois, Ingeborg J.; Lindeboom, Han J.; Hoekstra, Piet For the seaward harbour extension of the Port of Rotterdam in the Netherlands, approximately 220 million m3 sand was extracted between 2009 and 2013. In order to decrease the surface area of direct impact, the authorities permitted deep sand extraction, down to 20 m below the seabed. Biological and physical impacts of large-scale and deep sand extraction are still being investigated and largely unknown. For this reason, we investigated the colonization of demersal fish in a deep sand extraction site. Two sandbars were artificially created by selective dredging, copying naturally occurring meso-scale bedforms to increase habitat heterogeneity and increasing post-dredging benthic and demersal fish species richness and biomass. Significant differences in demersal fish species assemblages in the sand extraction site were associated with variables such as water depth, median grain size, fraction of very fine sand, biomass of white furrow shell (Abra alba) and time after the cessation of sand extraction. Large quantities of undigested crushed white furrow shell fragments were found in all stomachs and intestines of plaice (Pleuronectes platessa), indicating that it is an important prey item. One and two years after cessation, a significant 20-fold increase in demersal fish biomass was observed in deep parts of the extraction site. In the troughs of a landscaped sandbar however, a significant drop in biomass down to reference levels and a significant change in species assemblage was observed two years after cessation. The fish assemblage at the crests of the sandbars differed significantly from the troughs with tub gurnard (Chelidonichthys lucerna) being a Dufrêne-Legendre indicator species of the crests. This is a first indication of the applicability of landscaping techniques to induce heterogeneity of the seabed although it remains difficult to draw a strong conclusion due the lack of replication in the experiment. A new ecological equilibrium is not reached after 2 O'Neill, F. G.; Summerbell, K.; Ivanović, A. The contact demersal towed fishing gears make with the seabed can lead to penetration of the substrate, lateral displacement of the sediment and a pressure field transmitted through the sediment. It will also contribute to the overall drag of the fishing gear. Consequently, there can be environmental effects such as habitat alteration and benthic mortality, and impacts to the fuel efficiency of the fishing operation which will affect emissions of nitrogen oxides, sulphur oxides and greenhouse gases such as CO2. Here we present the results of experimental trials that measure the contact drag of a range of elements that represent some of the components of towed demersal gears that are in contact with the seabed. We show that the contact drag of the gear components depends on their weight, geometry, the type of sediment on which they are towed and whether they are rolling or not. As expected, the contact drag of each gear component increases as its weight increases and the drag of fixed elements is greater than that of the rolling ones. The dependence on aspect ratio is more complex and the drag (per unit area) of narrow cylinders is less than that of wider ones when they roll on the finer sediment or are fixed (not permitted to roll) on the coarser sediment. When they roll on the coarse sediment there is no dependence on aspect ratio. Our results also suggest that fixed components may penetrate the seabed to a lesser depth when they are towed at higher speeds but when they roll there is no such relationship. National Oceanic and Atmospheric Administration, Department of Commerce — Since 1992, the Habitat Ecology team has been conducting fishery independent, visual surveys of demersal fishes and associated habitats in deep water (20 to 900... The segregation of habitats of fish assemblages found in the chalk streams and rivers within the Wessex, South West and Southern Water Authority boundaries in southern England have been examined. Habitat segregation is the most frequent type of resource partitioning in natural communities. The habitat of individual fish species will be defined in order to determine the following: (1) the requirements of each species in terms of depth, current velocity, substrate, cover etc.; (2) identify the ... Bianchi, G.; Gislason, Henrik; Graham, K. . but particularly in high-latitude regions, we observe a decreasing trend in the slope, reflecting changes in size composition toward a relative decline in larger fish. The results from tropical regions are less conclusive, partly owing to the difficulty in obtaining consistent data series, but probably also......By analysing data sets from different world regions we add evidence to documented changes in demersal fish community structure that may be related to fishing. Changes are analysed by community properties that might be expected to capture relevant overall changes - size spectra slopes and intercepts...... because the generally higher growth rates of the constituent species make the slope less sensitive to changes in fishing. No evidence was found of any decline in species richness, while changes in diversity (richness and evenness) were caused either by changes in patterns of dominance or by changes... Stes Aleksej Vladimirovich Full Text Available In the paper, the data of the red king crab by-catch in demersal fishing in the South-Eastern part of the Barents Sea, including those in the areas forbidden to trawling are presented. The impact of the catch of demersal fish on the distribution of the king crab is analyzed. It was shown that intensive fishing contributes to the growth of crabs’ density, possibly, they are attracted by the wastes of fish factories. Full Text Available Suyatna I, Bratawinata AA, Sidik AS, Ruchaemi A (2011 Demersal fishes and their distribution in estuarine waters of Mahakam Delta, East Kalimantan. Biodiversitas 12: 204-210. The study aimed (i to identify of the demersal fishes, (ii to analyze the diversity and (iii to determine their distribution. Surveys were carried out between August 2009 and January 2010 in Mahakam Delta, East Kalimantan. Data were analyzed using several indices of Shannon Weaver, Sympson, Margalef species richness, and Bray Curtis distance. The canonical correspondence analysis (CCA was also used to correlate between fish species and their environmental factors and to show the fish distribution. Sixty samplings were done using bottom-trawl at various water depths from one to fourty two meters to collect the data. Taxonomically, during the study, 10 orders, 61 families, 87 genera and 131 species of fish with 43340 individuals were identified. Among the families, Leiognathidae was the most important group of fish, they distributed throughout the depths. Meanwhile CCA showed that Leiognathidae and Sciaenidae were observed to be rich in the shallow water. Generally, index of Shannon Weaver, Sympson and Margalef species richness ranged between; 0.52 and 2.48; 0.11 and 0.82; 2.24 and 18.61 respectively. Bray Curtis distance indicated the significant difference of individual number of demersal fishes between shallow and deep waters. Murphy, Fionn; Russell, Marie; Ewins, Ciaran; Quinn, Brian This study reports plastic ingestion in various fish found from coastal and offshore sites in Scottish marine waters. Coastal samples consisted of three demersal flatfish species (n=128) collected from the East and West coasts of Scotland. Offshore samples consisted of 5 pelagic species and 4 demersal species (n=84) collected from the Northeast Atlantic. From the coastal fish sampled, 47.7% of the gastrointestinal tracts contained macroplastic and microplastic. Of the 84 pelagic and demersal offshore fish, only 2 (2.4%) individuals from different species had ingested plastic identified as a clear polystyrene fibre and a black polyamide fibre. The average number of plastic items found per fish from all locations that had ingested plastic was 1.8 (±1.7) with polyamide (65.3%), polyethylene terephthalate (14.4%) and acrylic (14.4%) being the three most commonly found plastics. This study adds to the existing data on macroplastic and microplastic ingestion in fish species. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved. Tseng, C. M.; Hsieh, Y. C.; Chiang, C. Y.; Lamborg, C. H.; Chang, N. N.; Shiao, J. C. Limited knowledge still exists concerning the effects of size composition and trophic level (TL) on mercury levels in the demersal fishes associated with human activities in the marginal seas. In this study, we found evidence of strong control of TL on the Hg in fish and its biomagnification via food webs in the ECS. Total Hg in seven selected fish species, collected during the cruise OR1- 890 in July 2009, ranged from 2.6 and 256.2 ng g-1 (n=72). There were good linear relationships between Hg concentrations and fish body length (R2 = 0.79) and weight (R2 = 0.82), respectively, other than environmental variables (R2 = 0 0.03). It indicates that the Hg concentration in fish is mainly controlled by the growth mechanism of the fish itself through food chain transfer. In order to investigate how Hg levels in fish through trophic magnification associated with environmental changes, we hence developed the empirical method to calculate Hg accumulation rate (MAR) via the relationship of Hg concentration with the fish age for each fish species. The results further showed a significantly positive correlation of MAR with trophic levels, which relationship is Ln MAR =6.1 TL-15.8 (R2 = 0.89) in the ECS shelf. The magnitude of the slope (δMAR/δTL) as a biomagnification index of demersal fish shall provide the feasibility to compare Hg pollution situation among different marine ecosystems. Globally, the biomagnification indicator in the demersal fishes of the ECS is much greater than those in other marginal seas, suggesting high regional Hg pollution impacts from Mainland China. Jason E. Tanner Full Text Available The influence of sea-cage aquaculture on wildfish assemblages has received little attention outside of Europe. Sea-cage aquaculture of finfish is a major focus in South Australia, and while the main species farmed is southern bluefin tuna (Thunnus maccoyii, there is also an important yellowtail kingfish (Seriola lalandi industry. Yellowtail kingfish aquaculture did not appear to have any local or regional effects on demersal assemblages (primarily fish, but also some crustaceans surveyed by baited remote underwater video (BRUV in Fitzgerald Bay. We did, however, detect small scale spatial variations in assemblages within the bay. The type of bait used strongly influenced the assemblage recorded, with significantly greater numbers of fish attracted to deployments where sardines were used as the bait to compared to those with no bait. The pelleted feed used by the aquaculture industry was just as attractive as sardines at one site, and intermediate between sardines and no bait at the other. There was significant temporal variability in assemblages at both farm sites and one control site, while the second control site was temporally stable (over the 9 weeks of the study. Overall, the results suggested that aquaculture was having little if any impact on the abundance and assemblage structure of the demersal macrofauna in Fitzgerald Bay. Kirkman, Stephen P.; Yemane, Dawit; Atkinson, Lara J. Using long‐term survey data, changes in demersal faunal communities in the Benguela Current Large Marine Ecosystem were analysed at community and population levels to provide a comparative overview of the occurrence and timing of regime shifts. For South Africa, the timing of a community‐level sh......Using long‐term survey data, changes in demersal faunal communities in the Benguela Current Large Marine Ecosystem were analysed at community and population levels to provide a comparative overview of the occurrence and timing of regime shifts. For South Africa, the timing of a community... Koyanagi, Taku; Nakahara, Motokazu; Iimura, Mitsue Retention of 54 Mn, 59 Fe, 60 Co and 65 Zn by marine demersal fish, Ishigarei (Kareius bicoloratus) was observed by administering sediment-bound radioisotopes orally to the fishes to elucidate the contribution of sediment to the accumulation of radionuclides by marine benthic organisms. The sediment had high distribution coefficients for these radionuclides and from the result of leaching experiments with acidified seawater, considerable fractions of radioactive Mn, Co and Zn in the sediment were assumed to be leached in the stomach of the fishes. Retention patterns of the nuclides in the whole-body of the fishes were analyzed by peeling off method and two components were obtained for all the nuclides. The parameters which characterized the retention patterns suggested relatively high absorption efficiencies of the radionuclides except 59 Fe through the digestive tract of the fishes and the retention patterns of the slower component were supposed to be similar to those observed for the nuclides taken up from seawater or food by the dishes. Rapid and higher transfer of the absorbed radionuclides to the particular organs of the fishes suggested the important role of the sediment in the radioactive contamination of marine demersal fishes. (author) Lusher, A L; McHugh, M; Thompson, R C Microplastics are present in marine habitats worldwide and laboratory studies show this material can be ingested, yet data on abundance in natural populations is limited. This study documents microplastics in 10 species of fish from the English Channel. 504 Fish were examined and plastics found in the gastrointestinal tracts of 36.5%. All five pelagic species and all five demersal species had ingested plastic. Of the 184 fish that had ingested plastic the average number of pieces per fish was 1.90±0.10. A total of 351 pieces of plastic were identified using FT-IR Spectroscopy; polyamide (35.6%) and the semi-synthetic cellulosic material, rayon (57.8%) were most common. There was no significant difference between the abundance of plastic ingested by pelagic and demersal fish. Hence, microplastic ingestion appears to be common, in relatively small quantities, across a range of fish species irrespective of feeding habitat. Further work is needed to establish the potential consequences. Copyright © 2012 Elsevier Ltd. All rights reserved. Whitehouse, George A.; Buckley, Troy W.; Danielson, Seth L. Fishes are an important link in Arctic marine food webs, connecting production of lower trophic levels to apex predators. We analyzed 1773 stomach samples from 39 fish species collected during a bottom trawl survey of the eastern Chukchi Sea in the summer of 2012. We used hierarchical cluster analysis of diet dissimilarities on 21 of the most well sampled species to identify four distinct trophic guilds: gammarid amphipod consumers, benthic invertebrate generalists, fish and shrimp consumers, and zooplankton consumers. The trophic guilds reflect dominant prey types in predator diets. We used constrained analysis of principal coordinates (CAP) to determine if variation within the composite guild diets could be explained by a suite of non-diet variables. All CAP models explained a significant proportion of the variance in the diet matrices, ranging from 7% to 25% of the total variation. Explanatory variables tested included latitude, longitude, predator length, depth, and water mass. These results indicate a trophic guild structure is present amongst the demersal fish community during summer in the eastern Chukchi Sea. Regular monitoring of the food habits of the demersal fish community will be required to improve our understanding of the spatial, temporal, and interannual variation in diet composition, and to improve our ability to identify and predict the impacts of climate change and commercial development on the structure and functioning of the Chukchi Sea ecosystem. Bachok, Z.; Mansor, M.I.; Noordin, R.M. Fish stomachs from 18 demersal and pelagic fishes from the coast of Terengganu in Malaysia were examined. The components of the fishesÆ diets varied in number, weight, and their frequency of occurrence. The major food items in the stomachs of each species were determined using an Index of Relative Importance. A "conceptualö food web structure indicates that fish species in the study area can be classified into three predatory groups: (1) predators on largely planktivorous or pelagic species; ... Chen, C.; Bolle, L.J.; Boois I.J. de, Ingeborg Since 1972, the Demersal Fish Survey (DFS) in the Wadden Sea has been carried out with the RV Stern. Within a few years this vessel will be replaced by another vessel as a result of the current ship replacement policy of Rijkswaterstaat Rijksrederij. It is not yet clear which vessel will replace RV We examined larval and juvenile fish assemblage structure in relation to microhabitat variables within the St. Louis River estuary, a drowned river mouth of Lake Superior. Fish were sampled in vegetated beds throughout the estuary, across a gradient of vegetation types and densities (including disturbed, preserved and post-restoration sites). Canonical correspondence analysis, relating species abundances to environmental variables revealed that plant species richness, turbidity and aquatic plant cover were most influential in structuring assemblages. Results from this microhabitat analysis at this crucial life stage has potential to inform wetland restoration efforts within the St. Louis River and other Great Lake coastal wetlands. not applicable Brown, Lyndsay; Bresnan, Eileen; Summerbell, Keith; O'Neill, Finbarr Gerard To investigate the influence of towed demersal fishing gears on dinoflagellate cyst resuspension, towing trials with four gear components were carried out at three sites of differing sediment type in the Moray Firth, Scotland. Samples of sediment plumes were collected using plankton nets mounted on a towed sledge. Diversity of resuspended dinoflagellate cysts was similar at all sites and included Protoperidinium and Gonyaulax spp., Proroceratium reticulatum and unidentified 'round brown' cysts. Cyst concentrations per gram of resuspended sediment varied by gear component and sediment particle size distribution. Gear components with lower hydrodynamic drag generated wakes with smaller shear stresses, mobilising fewer larger sand particles, giving larger concentrations of cysts. Muddy sediments contained higher cyst concentrations which declined with increasing grain size. This study has shown that fishing gear and sediment type can influence the redistribution of dinoflagellate cysts and highlights the importance this may have in relation to dinoflagellate blooms. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved. Engelhard, George H.; Ellis, Jim R.; Payne, Mark How do species-rich fish assemblages respond to climate change or to other anthropogenic or environmental drivers? To explore this, a categorization concept is presented whereby species are assigned with respect to six ecotype classifications, according to biogeography, horizontal and vertical...... or combinations of them. The post-1989 warm biological regime appears to have favoured pelagic species more than demersal species. These community-level patterns agree with the expected responses of ecotypes to climate change and also with anticipated vulnerability to fishing pressure....... habitat preference, trophic guild, trophic level, or body size. These classification schemes are termed ecotypology, and the system is applied to fish in the North Sea using International Bottom Trawl Survey data. Over the period 1977–2008, there were changes in the North Sea fish community that can... Magurran, Anne E.; Dornelas, Maria; Moyes, Faye; Gotelli, Nicholas J.; McGill, Brian The role human activities play in reshaping biodiversity is increasingly apparent in terrestrial ecosystems. However, the responses of entire marine assemblages are not well-understood, in part, because few monitoring programs incorporate both spatial and temporal replication. Here, we analyse an exceptionally comprehensive 29-year time series of North Atlantic groundfish assemblages monitored over 5° latitude to the west of Scotland. These fish assemblages show no systematic change in species richness through time, but steady change in species composition, leading to an increase in spatial homogenization: the species identity of colder northern localities increasingly resembles that of warmer southern localities. This biotic homogenization mirrors the spatial pattern of unevenly rising ocean temperatures over the same time period suggesting that climate change is primarily responsible for the spatial homogenization we observe. In this and other ecosystems, apparent constancy in species richness may mask major changes in species composition driven by anthropogenic change. PMID:26400102 Full Text Available The composition and abundance of megabenthic fauna caught by the commercial trawl fleet in the Alboran Sea were studied. A total of 28 hauls were carried out at depths ranging from 50 to 640 m. As a result of a hierarchical classification analysis four assemblages were detected: (1 the outer shelf group (50-150 m, characterised by Octopus vulgaris and Cepola macrophthalma; (2 the upper slope group (151-350 m, characterised by Micromesistius poutassou, with Plesionika heterocarpus and Parapenaeus longirostris as secondary species; (3 the middle slope group (351-640 m, characterised by M. poutassou, Nephrops norvegicus and Caelorhincus caelorhincus, and (4 the small seamount Seco de los Olivos (310-360 m, characterised by M. poutassou, Helicolenus dactylopterus and Gadiculus argenteus, together with Chlorophthalmus agassizi, Stichopus regalis and Palinurus mauritanicus. The results also revealed significantly higher abundances in the Seco de los Olivos seamount, probably related to a higher food availability caused by strong localised currents and upwellings that enhanced primary production. Although depth proved to be the main structuring factor, others such as sediment type and food availability also appeared to be important. Differences between shelf and slope assemblages could be in part related to a greater dependence on benthic resources in the former and a higher use of planktonic resources in the latter. Methven, D. A.; Haedrich, R. L.; Rose, G. A. Twice monthly sampling over two 16 month periods at a shallow site on Newfoundland's east coast showed the fish assemblage to be dominated by four taxa ( Gasterosteus aculeatus, G. wheatlandi, Osmerus mordax, Gadus spp.) that accounted for 96% of the individuals collected. Of the 16 479 fish measured, 65% were adults based on the estimated size of first spawning. The fish assemblage was dominated (86%) by species with demersal eggs, several of which spawn at the same shallow sites used by juveniles as nursery sites. Coastal spawning and demersal eggs maintain offspring in coastal nursery areas where survival is thought to be increased. Number of species and number of fish were both correlated with water temperature being highest from mid-summer to early autumn and lowest in winter. Temperature, time of spawning, and movements of juveniles and adults facilitated grouping species into five assemblages based on seasonal abundance: seasonal periodic species (summer and winter), regular species, regular species collected in all seasons except winter, and occasional (rare) species. At the diel scale, two consistent species groupings were observed: species that showed no significant difference between day and night and species caught primarily at night. Number of night species exceeded day species by a factor of two. No seine-caught species in shallow water exhibited significantly higher catches during the day. Observations by SCUBA divers indicated some species were more abundant during day time at slightly deeper depths. This observation in conjunction with day and night seining in shallower water, suggests these species aggregate in deeper water during day and move to shallow waters at night. Miranda, Leandro E.; Wigen, S. L.; Dagel, Jonah D. Reservoirs constructed on floodplain rivers are unique because the upper reaches of the impoundment may include extensive floodplain environments. Moreover, reservoirs that experience large periodic water level fluctuations as part of their operational objectives seasonally inundate and dewater floodplains in their upper reaches, partly mimicking natural inundations of river floodplains. In four flood control reservoirs in Mississippi, USA, we explored the dynamics of connectivity between reservoirs and adjacent floodplains and the characteristics of fish assemblages that develop in reservoir floodplains relative to those that develop in reservoir bays. Although fish species richness in floodplains and bays were similar, species composition differed. Floodplains emphasized fish species largely associated with backwater shallow environments, often resistant to harsh environmental conditions. Conversely, dominant species in bays represented mainly generalists that benefit from the continuous connectivity between the bay and the main reservoir. Floodplains in the study reservoirs provided desirable vegetated habitats at lower water level elevations, earlier in the year, and more frequently than in bays. Inundating dense vegetation in bays requires raising reservoir water levels above the levels required to reach floodplains. Therefore, aside from promoting distinct fish assemblages within reservoirs and helping promote diversity in regulated rivers, reservoir floodplains are valued because they can provide suitable vegetated habitats for fish species at elevations below the normal pool, precluding the need to annually flood upland vegetation that would inevitably be impaired by regular flooding. Published 2013. This article is a U.S. Government work and is in the public domain in the USA. Dorman, Stacey R; Harvey, Euan S; Newman, Stephen J Baited underwater video techniques are increasingly being utilised for assessing and monitoring demersal fishes because they are: 1) non extractive, 2) can be used to sample across multiple habitats and depths, 3) are cost effective, 4) sample a broader range of species than many other techniques, 5) and with greater statistical power. However, an examination of the literature demonstrates that a range of different bait types are being used. The use of different types of bait can create an additional source of variability in sampling programs. Coral reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were sampled using baited remote underwater stereo-video systems. One-hour stereo-video recordings were collected for four different bait treatments (pilchards, cat food, falafel mix and no bait (control)) from sites inside and outside a targeted fishery closure (TFC). In total, 5209 individuals from 132 fish species belonging to 41 families were recorded. There were significant differences in the fish assemblage structure and composition between baited and non-baited treatments (Pcat food and pilchards contained similar ingredients and were found to record similar components of the fish assemblage. There were no significant differences in the fish assemblages in areas open or closed to fishing, regardless of the bait used. Investigation of five targeted species indicated that the response to different types of bait was species-specific. For example, the relative abundance of Pagrus auratus was found to increase in areas protected from fishing, but only in samples baited with pilchards and cat food. The results indicate that the use of bait in conjunction with stereo-BRUVs is advantageous. On balance, the use of pilchards as a standardised bait for stereo-BRUVs deployments is justified for use along the mid-west coast of Western Australia. Stacey R Dorman Full Text Available Baited underwater video techniques are increasingly being utilised for assessing and monitoring demersal fishes because they are: 1 non extractive, 2 can be used to sample across multiple habitats and depths, 3 are cost effective, 4 sample a broader range of species than many other techniques, 5 and with greater statistical power. However, an examination of the literature demonstrates that a range of different bait types are being used. The use of different types of bait can create an additional source of variability in sampling programs. Coral reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were sampled using baited remote underwater stereo-video systems. One-hour stereo-video recordings were collected for four different bait treatments (pilchards, cat food, falafel mix and no bait (control from sites inside and outside a targeted fishery closure (TFC. In total, 5209 individuals from 132 fish species belonging to 41 families were recorded. There were significant differences in the fish assemblage structure and composition between baited and non-baited treatments (P<0.001, while no difference was observed with species richness. Samples baited with cat food and pilchards contained similar ingredients and were found to record similar components of the fish assemblage. There were no significant differences in the fish assemblages in areas open or closed to fishing, regardless of the bait used. Investigation of five targeted species indicated that the response to different types of bait was species-specific. For example, the relative abundance of Pagrus auratus was found to increase in areas protected from fishing, but only in samples baited with pilchards and cat food. The results indicate that the use of bait in conjunction with stereo-BRUVs is advantageous. On balance, the use of pilchards as a standardised bait for stereo-BRUVs deployments is justified for use along the mid-west coast of Western Australia. Natália Carla Fernandes Medeiros Dantas Full Text Available ABSTRACT For the demersal fish that inhabit sandy beaches, the variation between day and night periods represents a determinant factor in their behavior, especially for species that live in shallow waters. This research aims at determining whether there are differences in the fish assemblage structure of the sandy beach of São Cristóvão, RN, Brazil, between diurnal and nocturnal periods. Samplings were carried out in 2011, during spring high tide period, with an otter trawl net. Dissimilarity between diurnal and nocturnal fish assemblages was confirmed by PERMANOVA results. No statistical differences were observed for richness and diversity of fish assemblage between day and night periods. The first and third order carnivores were the significantly more representative trophic categories during night and day periods, respectively. Only four species presented significant differences regarding total length of fish between the periods. The demersal fish assemblage of São Cristóvão beach presented variations in the density of individuals between day and night periods. Dissimilarities were also recorded in trophic categories and in total lengths of individuals; however this occurred as a result of the high density of some species. The low depth of the beach may prevent the establishment of larger size adult fish, thus becoming a favourable environment for juveniles and small-sized fish species. Madsen, Nina A H; Aarsæther, Karl G; Herrmann, Bent Demersal Seining is an active fishing method applying two long seine ropes and a seine net. Demersal seining relies on fish responding to the seine rope as it moves during the fishing process. The seine ropes and net are deployed in a specific pattern encircling an area on the seabed. In some variants of demersal seining the haul-in procedure includes a towing phase where the fishing vessel moves forward before starting to winch in the seine ropes. The initial seine rope encircled area, the gradual change in it during the haul-in process and the fish's reaction to the moving seine ropes play an important role in the catch performance of demersal seine fishing. The current study investigates this subject by applying computer simulation models for demersal seine fishing. The demersal seine fishing is dynamic in nature and therefore a dynamic model, SeineSolver is applied for simulating the physical behaviour of the seine ropes during the fishing process. Information about the seine rope behaviour is used as input to another simulation tool, SeineFish that predicts the catch performance of the demersal seine fishing process. SeineFish implements a simple model for how fish at the seabed reacts to an approaching seine rope. Here, the SeineSolver and SeineFish tools are applied to investigate catching performance for a Norwegian demersal seine fishery targeting cod (Gadus morhua) in the coastal zone. The effect of seine rope layout pattern and the duration of the towing phase are investigated. Among the four different layout patterns investigated, the square layout pattern was predicted to perform best; catching 69%-86% more fish than would be obtained with the rectangular layout pattern. Inclusion of a towing phase in the fishing process was found to increase the catch performance for all layout patterns. For the square layout pattern, inclusion of a towing phase of 15 or 35 minutes increased the catch performance by respectively 37% and 48% compared to fishing without Elliott, Sophie A M; Sabatino, Alessandro D; Heath, Michael R; Turrell, William R; Bailey, David M Nature conservation and fisheries management often focus on particular seabed features that are considered vulnerable or important to commercial species. As a result, individual seabed types are protected in isolation, without any understanding of what effect the mixture of seabed types within the landscape has on ecosystem functions. Here we undertook predictive seabed modelling within a coastal marine protected area using observations from underwater stereo-video camera deployments and environmental information (depth, wave fetch, maximum tidal speeds, distance from coast and underlying geology). The effect of the predicted substratum type, extent and heterogeneity or the diversity of substrata, within a radius of 1500 m around each camera deployment of juvenile gadoid relative abundance was analysed. The predicted substratum model performed well with wave fetch and depth being the most influential predictor variables. Gadus morhua (Atlantic cod) were associated with relatively more rugose substrata (Algal-gravel-pebble and seagrass) and heterogeneous landscapes, than Melanogrammus aeglefinus (haddock) or Merlangius merlangus (whiting) (sand and mud). An increase in M. merlangus relative abundance was observed with increasing substratum extent. These results reveal that landscape effects should be considered when protecting the seabed for fish and not just individual seabed types. The landscape approach used in this study therefore has important implications for marine protected area, fisheries management and monitoring advice concerning demersal fish populations. Krag, Ludvig Ahm; Madsen, Niels; Karlsen, Junita A rigid separator frame with three vertically stacked codends was used to study fish behaviour in the extension piece of a demersal trawl. A video camera recorded fish as they encountered the separator frame. Ten hauls were conducted in a mixed species fishery in the northern North Sea. Fish... Full Text Available The study was carried out in two fishing grounds on the Mediterranean continental shelf: one in the Adriatic Sea and one in the Catalan Sea. Samplings on board otter trawlers were performed from November 2002 to December 2003 in the Catalan Sea and from February 2003 to January 2004 in the Adriatic Sea. The Adriatic fishing ground was affected by high fishing intensity from January to June, while the Catalan area was highly exploited from September to February. Fishing activity in the Adriatic area was closed for 45 days, and 62 days in the Catalan area; both periods were in summer. Totals of 92 and 88 species were collected in the Adriatic and Catalan fishing grounds respectively. The species composition of the retained and discarded fractions showed close agreement between the two areas. Mullus barbatus showed very low discard rates in both areas, as well as Loligo vulgaris in the Catalan Sea and Merluccius merluccius in the Adriatic Sea. In both fishing grounds Squilla mantis showed high catch rates with low discards, except in March in the Catalan area. In the Adriatic Sea Liocarcinus depurator was characterized by large discard fractions. In both fishing grounds the retained fraction was slightly higher in the high fishing intensity periods than in the low intensity ones (Adriatic Sea: 0.613 vs 0.524; Catalan Sea: 0.597 vs 0.539, even though the Kruskall Wallis test revealed significant differences (p Mullen, J.A.; Bramblett, R.G.; Guy, C.S.; Zale, A.V.; Roberts, D.W. Prairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages and abiotic conditions varied more spatially than temporally. The most important variables explaining fish assemblage structure were longitudinal position and the proportion of fine substrates. The proportion of fine substrates increased proceeding upstream, approaching 100% in all five streams, and species richness declined upstream with increasing fine substrates. High levels of fine substrate in the upper reaches appeared to limit the distribution of obligate lithophilic fish species to reaches further downstream. Species richness and substrates were similar among all five streams at the lowermost and uppermost sites. However, in the middle reaches, species richness increased, the amount of fine substrate decreased, and connectivity increased as watershed area increased. Season and some dimensions of habitat (including thalweg depth, absolute distance to the main-stem river, and watershed size) were not essential in explaining the variation in fish assemblages. Fish species richness varied more temporally than overall fish assemblage structure did because common species were consistently abundant across seasons, whereas rare species were sometimes absent or perhaps not detected by sampling. The similarity in our results among five streams varying in watershed size and those from other studies supports the generalization that spatial variation exceeds temporal variation in the fish assemblages of prairie and warmwater streams. Furthermore, given longitudinal position, substrate, and stream size, general predictions regarding fish assemblage structure and function in prairie streams are possible. ?? American Roseman, Edward F.; O'Brien, Timothy P.; Riley, Stephen C.; Farha, Steve A.; French, John R. The U.S.Geological Survey Great Lakes Science Center has conducted trawl surveys to assess annual changes in the deepwater demersal fish community of Lake Huron since 1973. Since 1992, surveys have been carried out using a 21 m wing trawl towed on-contour at depths ranging from 9 to 110 m on fixed transects. Sample sites include five ports in U.S. waters with less frequent sampling near Goderich, Ontario. The 2008 fall bottom trawl survey was carried out between October 24 and November 20, 2008 and sampled only the three northern U.S. ports at DeTour, Hammond Bay, and Alpena due to mechanical problems with the research vessel and prolonged periods of bad weather. Therefore, all data presented for 2008 are based on samples collected from these ports. Compared to previous years, alewife populations in Lake Huron remain at low levels after collapsing in 2004. Age-0 alewife density and biomass appears to have increased slightly but overall levels remain near the nadir observed in 2004. Density and biomass of adult and juvenile rainbow smelt showed a decrease from 2007 despite record-high abundance of juveniles observed in 2005, suggesting recruitment was low. Numbers of adult and juvenile bloater were low despite recent high year-classes. Abundances for most other prey species were similar to the low levels observed in 2005 - 2007. We captured one wild juvenile lake trout in 2008 representing the fifth consecutive year that wild lake trout were captured in the survey. Based on pairwise graphical comparisons and nonparametric correlation analyses, dynamics of prey abundance at the three northern ports followed lakewide trends since 1992. Density of benthic macroinvertebrates was at an all-time low in 2008 since sampling began in 2001. The decline in abundance was due to decreases in all taxonomic groups and a large reduction in recruitment of quagga mussels. Density of Diporeia at northern ports in 2008 was the lowest observed. Diporeia were found only at 73-m sites of Samoilys, Melita; Roche, Ronan; Koldewey, Heather; Turner, John Understanding the drivers of variability in the composition of fish assemblages across the Indo-Pacific region is crucial to support coral reef ecosystem resilience. Whilst numerous relationships and feedback mechanisms between the functional roles of coral reef fishes and reef benthic composition have been investigated, certain key groups, such as the herbivores, are widely suggested to maintain reefs in a coral-dominated state. Examining links between fishes and reef benthos is complicated by the interactions between natural processes, disturbance events and anthropogenic impacts, particularly fishing pressure. This study examined fish assemblages and associated benthic variables across five atolls within the Chagos Archipelago, where fishing pressure is largely absent, to better understand these relationships. We found high variability in fish assemblages among atolls and sites across the archipelago, especially for key groups such as a suite of grazer-detritivore surgeonfish, and the parrotfishes which varied in density over 40-fold between sites. Differences in fish assemblages were significantly associated with variable levels of both live and recently dead coral cover and rugosity. We suggest these results reflect differing coral recovery trajectories following coral bleaching events and a strong influence of 'bottom-up' control mechanisms on fish assemblages. Species level analyses revealed that Scarus niger, Acanthurus nigrofuscus and Chlorurus strongylocephalos were key species driving differences in fish assemblage structure. Clarifying the trophic roles of herbivorous and detritivorous reef fishes will require species-level studies, which also examine feeding behaviour, to fully understand their contribution in maintaining reef resilience to climate change and fishing impacts. Roche, Ronan; Koldewey, Heather; Turner, John Understanding the drivers of variability in the composition of fish assemblages across the Indo-Pacific region is crucial to support coral reef ecosystem resilience. Whilst numerous relationships and feedback mechanisms between the functional roles of coral reef fishes and reef benthic composition have been investigated, certain key groups, such as the herbivores, are widely suggested to maintain reefs in a coral-dominated state. Examining links between fishes and reef benthos is complicated by the interactions between natural processes, disturbance events and anthropogenic impacts, particularly fishing pressure. This study examined fish assemblages and associated benthic variables across five atolls within the Chagos Archipelago, where fishing pressure is largely absent, to better understand these relationships. We found high variability in fish assemblages among atolls and sites across the archipelago, especially for key groups such as a suite of grazer-detritivore surgeonfish, and the parrotfishes which varied in density over 40-fold between sites. Differences in fish assemblages were significantly associated with variable levels of both live and recently dead coral cover and rugosity. We suggest these results reflect differing coral recovery trajectories following coral bleaching events and a strong influence of ‘bottom-up’ control mechanisms on fish assemblages. Species level analyses revealed that Scarus niger, Acanthurus nigrofuscus and Chlorurus strongylocephalos were key species driving differences in fish assemblage structure. Clarifying the trophic roles of herbivorous and detritivorous reef fishes will require species-level studies, which also examine feeding behaviour, to fully understand their contribution in maintaining reef resilience to climate change and fishing impacts. PMID:29351566 Chaalali, Aurélie; Brind'Amour, Anik; Dubois, Stanislas F; Le Bris, Hervé Through their tissues or activities, engineer species create, modify, or maintain habitats and alter the distribution and abundance of many plants and animals. This study investigates key ecological functions performed by an engineer species that colonizes coastal ecosystems. The gregarious tubiculous amphipod Haploops nirae is used as a biological model. According to previous studies, the habitat engineered by H. nirae (i.e., Haploops habitat) could provide food and natural shelter for several benthic species such as benthic diatoms belonging to the gender Navicula , the micrograzer Geitodoris planata, or the bivalve Polititapes virgineus . Using data from scientific surveys conducted in two bays, this study explored whether (1) the Haploops sandy-mud community modifies invertebrate and ichthyologic community structure (diversity and biomass); (2) H. nirae creates a preferential feeding ground; and (3) this habitat serves as a refuge for juvenile fish. Available Benthic Energy Coefficients, coupled with more traditional diversity indices, indicated higher energy available in Haploops habitat than in two nearby habitats (i.e., Sternaspis scutata and Amphiura filiformis/Owenia fusiformis habitats). The use of isotopic functional indices (IFIs) indicated (1) a higher functional richness in the Haploops habitat, related to greater diversity in food sources and longer food chains; and (2) a higher functional divergence, associated with greater consumption of a secondary food source. At the invertebrate-prey level, IFIs indicated little specialization and little trophic redundancy in the engineered habitat, as expected for homogenous habitats. Our results partly support empirical knowledge about engineered versus nonengineered habitats and also add new perspectives on habitat use by fish and invertebrate species. Our analyses validated the refuge-area hypothesis for a few fish species. Although unique benthic prey assemblages are associated with Haploops habitat, the Granzotti, Rafaela Vendrametto; Miranda, Leandro E.; Agostinho, Angelo A.; Gomes, Luiz Carlos Impoundments alter connectivity, sediment transport and water discharge in rivers and floodplains, affecting recruitment, habitat and resource availability for fish including benthic invertivorous fish, which represent an important link between primary producers and higher trophic levels in tropical aquatic ecosystems. We investigated long-term changes to water regime, water quality, and invertivorous fish assemblages pre and post impoundment in three rivers downstream of Porto Primavera Reservoir in south Brazil: Paraná, Baía and Ivinhema rivers. Impacts were distinct in the Paraná River, which is fully obstructed by the dam, less evident in the Baía River which is partially obstructed by the dam, but absent in the unimpounded Ivinhema River. Changes in water regime were reflected mainly as changes in water-level fluctuation with little effect on timing. Water transparency increased in the Paraná River post impoundment but did not change in the Baía and Ivinhema rivers. Changes in fish assemblages included a decrease in benthic invertivorous fish in the Paraná River and a shift in invertivorous fish assemblage structure in the Baía and Paraná rivers but not in the unimpounded Ivinhema River. Changes in water regime and water transparency, caused by impoundment, directly or indirectly impacted invertivorous fish assemblages. Alterations of fish assemblages following environmental changes have consequences over the entire ecosystem, including a potential decrease in the diversity of mechanisms for energy flow. We suggest that keeping existing unimpounded tributaries free of dams, engineering artificial floods, and intensive management of fish habitat within the floodplain may preserve native fish assemblages and help maintain functionality and ecosystem services in highly impounded rivers. Luisa Resende Manna Full Text Available The habitat use is an individual choice that is influenced by physical conditions such as substrate type, food resources availability and adequate depth. However, habitat use is often measured only through interspecific variability because intraspecific variability is supposed to be low. Here, the differences in habitat use by two stream fish assemblages in two different environments (Brazilian rainforest and semiarid were investigated at both interspecific and intraspecific levels. We performed 55 hours of underwater observation in a 200 meters long stretch in each stream and quantified the following habitat descriptors: (i water velocity, (ii distance from the stream bank, (iii substratum, (iv water column depth, (v aquatic cover, and (vi canopy percentage. To compare intra and interspecific variability we summarized the multivariate habitat use databases using Principal Components Analysis (PCA on Euclidean distance. An Analysis of Similarity (ANOSIM was performed to test the differences in habitat use by the two assemblages. Besides, in each fish community we did an Analysis of Variance (ANOVA to test within vs between species variability for individual position on each PCA axes. To go further than these univariate tests, the differences among the species and assemblages were tested with Permutational Multivariate Analysis of Variance (PERMANOVA. The habitat use between assemblages was significantly different (ANOSIM – R=0.14; p<0.001. PERMANOVA revealed significant differences among species in both assemblages (Rainforest - F=7.25; p<0.001; semiarid - F=4.84; p<0.001. Lower F values in the semiarid assemblage revealed a higher level of intraspecific variability for this assemblage. Our findings showed high intra and interspecific variability in both stream fish assemblages and highlight the importance of measuring individual’s differences for this feature of fish biodiversity. Additionally, the versatility described for tropical André Pereira Cattani Full Text Available Abstract Baía Norte (North Bay in Santa Catarina State is considered a typical coastal bay and is surrounded by a network of Marine Protected Areas. The objectives of this study were to describe the composition of the demersal fish assemblage, identify seasonal and spatial structures on a fine scale and evaluate the role of habitat descriptors and abiotic variables affecting the fish assemblage structure. Seasonal samplings were conducted in 2005, using bottom trawls in six pre-established areas in Baía Norte in summer, fall, winter and spring. Simultaneously with each trawl, environmental data were collected with a multiparameter probe. Temporal and spatial differences in fish abundance were tested by a PERMANOVA. To illustratethe differences detected graphically we ran a canonical analysis of principal coordinates (CAP. The influence of environmental variables on the fish fauna was evaluated using a Distant Based Linear Model (DistLM with Akaike's information criterion (AIC. A total of 9,888 specimens, distributed in 27 families and 62 species, were collected. Citharichthys spilopterus was the most abundant species. PERMANOVA detected differences for abundance between seasons, areas and interaction among all the factors. The DISTLM selected temperature and pH. The results highlight seasonality as an important factor in the structuring of fish fauna of the study place. Wehkamp, Stephanie; Fischer, Philipp In the coming decades, artificial defence structures will increase in importance worldwide for the protection of coasts against the impacts of global warming. However, the ecological effects of such structures on the natural surroundings remain unclear. We investigated the impact of experimentally introduced tetrapod fields on the demersal fish community in a hard-bottom area in the southern North Sea. The results indicated a significant decrease in fish abundance in the surrounding area caused by migration effects towards the artificial structures. Diversity (HB) and evenness (E) values exhibited greater variation after the introduction of the tetrapods. Additionally, a distinct increase in young-of-the-year (YOY) fish was observed near the structures within the second year after introduction. We suggest that the availability of adequate refuges in combination with additional food resources provided by the artificial structures has a highly species-specific attraction effect. However, these findings also demonstrate that our knowledge regarding the impact of artificial structures on temperate fish communities is still too limited to truly understand the ecological processes that are initiated by the introduction of artificial structures. Long-term investigations and additional experimental in situ work worldwide will be indispensable for a full understanding of the mechanisms by which coastal defence structures interact with the coastal environment. Copyright © 2012 Elsevier Ltd. All rights reserved. Brenkman, Samuel J.; Connolly, Patrick J. Rivers and streams that drain from Olympic, Mount Rainier, and North Cascades National Parks are among the most protected corridors in the lower 48 States, and represent some of the largest tracts of contiguous, undisturbed habitat throughout the range of several key fish species of the Pacific Northwest. These watersheds are of high regional importance as freshwater habitat sanctuaries for native fish, where habitat conditions are characterized as having little to no disturbance from development, channelization, impervious surfaces, roads, diversions, or hydroelectric projects. Fishery resources are of high ecological and cultural importance in Pacific Northwest National Parks, and significantly contribute to economically important recreational, commercial, and tribal fisheries. This protocol describes procedures to monitor trends in fish assemblages, fish abundance, and water temperature in eight rivers and five wadeable streams in Olympic National Park during summer months, and is based on 4 years of field testing. Fish assemblages link freshwater, marine, and terrestrial ecosystems. They also serve as focal resources of national parks and are excellent indicators of ecological conditions of rivers and streams. Despite the vital importance of native anadromous and resident fish populations, there is no existing monitoring program for fish assemblages in the North Coast and Cascades Network. Specific monitoring objectives of this protocol are to determine seasonal and annual trends in: (1) fish species composition, (2) timing of migration of adult fish, (3) relative abundance, (4) age and size structure, (5) extent of non-native and hatchery fish, and (6) water temperature. To detect seasonal and annual trends in fish assemblages in reference sites, we rely on repeated and consistent annual sampling at each monitoring site. The general rationale for the repeated sampling of reference sites is to ensure that we account for the high interannual variability in fish Full Text Available This study describes the structure of coral and fish assemblages of a group of small islands and pinnacles in the vicinity of Maptaput deep sea port, Rayong Province, Thailand during 2002. The coral and fish assemblages at Saket Island and nearby pinnacle, Hin-Yai, which are located less than 1 km from the deep sea port, had changed. Living coral cover in 2002 was 8% at Hin-Yai and 4% at Saket Island which decreased from 33% and 64%, respectively in the previous report in 1992. Numbers of coral species at Saket Island decreased from 41 species to 13 species. Acropora spp. that previously dominated the area had nearly disappeared. For fishes, a total of 40 species were found in 2002 the numbers decreased to only 6 species at Saket Island and 36 species at Hin-Yai. Fishes that dominated the area are small pomacentrids. After 1997, the conditions of coral and fish assemblages at Saket Island and Hin-Yai had markedly changed, whereas, the conditions found in the nearby area are much better. Sediment load from port construction was the primary cause of the degradation. This should indicate the adverse effect of sedimentation on coral and reef fish assemblages at Maptaput. Coral communities developed on rock pinnacles west of Maptaput deep-sea port are reported and described herein for the first time. Darling, Emily S.; Graham, Nicholas A. J.; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.; Pratchett, Morgan S.; Wilson, Shaun K. With the ongoing loss of coral cover and the associated flattening of reef architecture, understanding the links between coral habitat and reef fishes is of critical importance. Here, we investigate whether considering coral traits and functional diversity provides new insights into the relationship between structural complexity and reef fish communities, and whether coral traits and community composition can predict structural complexity. Across 157 sites in Seychelles, Maldives, the Chagos Archipelago, and Australia's Great Barrier Reef, we find that structural complexity and reef zone are the strongest and most consistent predictors of reef fish abundance, biomass, species richness, and trophic structure. However, coral traits, diversity, and life histories provided additional predictive power for models of reef fish assemblages, and were key drivers of structural complexity. Our findings highlight that reef complexity relies on living corals—with different traits and life histories—continuing to build carbonate skeletons, and that these nuanced relationships between coral assemblages and habitat complexity can affect the structure of reef fish assemblages. Seascape-level estimates of structural complexity are rapid and cost effective with important implications for the structure and function of fish assemblages, and should be incorporated into monitoring programs. Sri Susilo, Endang; Nugroho Sugianto, Denny; Munasik; Nirwani; Adhi Suryono, Chrisna Seagrass beds promote high species diversity, abundance and biomass, and become important habitats for some economically important fishes. Plants of seagrasses result in structurally highly complex habitats and offering feeding grounds, shelter from predation as well as nursery areas for diverse fish assemblages. However, research on fish communities in Southeast Asian seagrass bed is rarely conducted. In the present study fish assemblages in seagrass beds with different parameters (cover, diversity and similarity indices, domination) was investigated in the Karimunjawa Islands, Indonesia. The purpose of this study were to assess whether fish assemblages differ concerning on the abundance and the species number. This study was conducted on the seagrass bed on Karimunjawa Islands in Java Sea, particularly in the water of Menjangan Besar and Menjangan Kecil Island. Line-quadrant transect was used to assess seagrass data, while the occurrence and individual number of fish harboured in the selected seagrass bed was counted by using underwater visual census in the stationary point count transects. Seagrass cover in Menjangan Kecil Island (41%) with various canopy included both upper and lower canopy was considerable higher than those in Menjangan Besar Island (5%). Fish diversity, species composition and abundance are considerably different between the two study sites. This study revealed that seagrass density or cover and canopy structure affected the fish abundance and species number harboured. Marchal, P.; Ulrich, Clara; Korsbrekke, K. mortality estimates from XSA (eXtended Survivors Analysis) are accurate. IFP2 is derived from the GLM analysis of the difference between the Log-CPUE of a vessel and the average Log-CPUE of a set of reference vessels, which are chosen with regards to the stability of their Log-CPUE over time. IFP3...... is derived from the GLM analysis of the Log-CPUE of a vessel relative to some external survey abundance index. Particular attention is paid to the horsepower and year effects in IFP1, IFP2, and IFP3. This methodology is applied to the Danish, Dutch, English and Norwegian demersal fisheries of the North Sea... Richardson, Laura E; Graham, Nicholas A J; Pratchett, Morgan S; Eurich, Jacob G; Hoey, Andrew S Global climate change is altering community composition across many ecosystems due to nonrandom species turnover, typically characterized by the loss of specialist species and increasing similarity of biological communities across spatial scales. As anthropogenic disturbances continue to alter species composition globally, there is a growing need to identify how species responses influence the establishment of distinct assemblages, such that management actions may be appropriately assigned. Here, we use trait-based analyses to compare temporal changes in five complementary indices of reef fish assemblage structure among six taxonomically distinct coral reef habitats exposed to a system-wide thermal stress event. Our results revealed increased taxonomic and functional similarity of previously distinct reef fish assemblages following mass coral bleaching, with changes characterized by subtle, but significant, shifts toward predominance of small-bodied, algal-farming habitat generalists. Furthermore, while the taxonomic or functional richness of fish assemblages did not change across all habitats, an increase in functional originality indicated an overall loss of functional redundancy. We also found that prebleaching coral composition better predicted changes in fish assemblage structure than the magnitude of coral loss. These results emphasize how measures of alpha diversity can mask important changes in the structure and functioning of ecosystems as assemblages reorganize. Our findings also highlight the role of coral species composition in structuring communities and influencing the diversity of responses of reef fishes to disturbance. As new coral species configurations emerge, their desirability will hinge upon the composition of associated species and their capacity to maintain key ecological processes in spite of ongoing disturbances. © 2018 John Wiley & Sons Ltd. Marchal, P.; Ulrich, C.; Korsbrekke, K.; Pastoors, M.A.; Rackham, B. The scope of this study is to identify temporal dynamics in fishing power, by deriving three different indices (IFP1, IFP2, IFP3) based on three independent methods. IFP1 is derived from the GLM analysis of the relationship between fishing mortality and fishing effort, assuming that total fishing Depth reduction is a natural process in floodplain lakes, but in many basins has been accelerated by anthropogenic disturbances. A diverse set of 42 floodplain lakes in the Yazoo River Basin (Mississippi, USA) was examined to test the hypothesis of whether depth reduction was a key determinant of water quality and fish assemblage structure. Single and multiple variable analyses were applied to 10 commonly monitored water variables and 54 fish species. Results showed strong associations between depth and water characteristics, and between depth and fish assemblages. Deep lakes provided less variable environments, clearer water, and a wider range of microhabitats than shallow lakes. The greater environmental stability was reflected by the dominant species in the assemblages, which included a broader representation of large-body species, species less tolerant of extreme water quality, and more predators. Stability in deep lakes was further reflected by reduced among-lake variability in taxa representation. Fish assemblages in shallow lakes were more variable than deep lakes, and commonly dominated by opportunistic species that have early maturity, extended breeding seasons, small adult size, and short lifespan. Depth is a causal factor that drives many physical and chemical variables that contribute to organizing fish assemblages in floodplain lakes. Thus, correlations between fish and water transparency, temperature, oxygen, trophic state, habitat structure, and other environmental descriptors may ultimately be totally or partly regulated by depth. In basins undergoing rapid anthropogenic modifications, local changes forced by depth reductions may be expected to eliminate species available from the regional pool and could have considerable ecological implications. ?? 2010 Springer Basel AG (outside the USA). Musil, J.; Adámek, Zdeněk; Baranyi, Ch. Roč. 15, č. 3-4 (2007), s. 217-226 ISSN 0967-6120. [New Challenges in Pond Aquaculture. České Budějovice, 26.04.2005-28.04.2005] Institutional research plan: CEZ:AV0Z60930519 Keywords : fish assemblage * pond canal * species richness * seasonal dynamics * alien species Subject RIV: GL - Fishing Impact factor: 0.828, year: 2007 Grober-Dunsmore, R.; Frazer, T.K.; Beets, J.P.; Lindberg, W.J.; Zwick, P.; Funicelli, N.A. Management of tropical marine environments calls for interdisciplinary studies and innovative methodologies that consider processes occurring over broad spatial scales. We investigated relationships between landscape structure and reef fish assemblage structure in the US Virgin Islands. Measures of landscape structure were transformed into a reduced set of composite indices using principal component analyses (PCA) to synthesize data on the spatial patterning of the landscape structure of the study reefs. However, composite indices (e.g., habitat diversity) were not particularly informative for predicting reef fish assemblage structure. Rather, relationships were interpreted more easily when functional groups of fishes were related to individual habitat features. In particular, multiple reef fish parameters were strongly associated with reef context. Fishes responded to benthic habitat structure at multiple spatial scales, with various groups of fishes each correlated to a unique suite of variables. Accordingly, future experiments should be designed to test functional relationships based on the ecology of the organisms of interest. Our study demonstrates that landscape-scale habitat features influence reef fish communities, illustrating promise in applying a landscape ecology approach to better understand factors that structure coral reef ecosystems. Furthermore, our findings may prove useful in design of spatially-based conservation approaches such as marine protected areas (MPAs), because landscape-scale metrics may serve as proxies for areas with high species diversity and abundance within the coral reef landscape. ?? 2007 Springer Science+Business Media B.V. Fischer, Jesse R.; Quist, Michael C. Characterizing fish assemblages in lentic ecosystems is difficult, and multiple sampling methods are almost always necessary to gain reliable estimates of indices such as species richness. However, most research focused on lentic fish sampling methodology has targeted recreationally important species, and little to no information is available regarding the influence of multiple methods and timing (i.e., temporal variation) on characterizing entire fish assemblages. Therefore, six lakes and impoundments (48–1,557 ha surface area) were sampled seasonally with seven gear types to evaluate the combined influence of sampling methods and timing on the number of species and individuals sampled. Probabilities of detection for species indicated strong selectivities and seasonal trends that provide guidance on optimal seasons to use gears when targeting multiple species. The evaluation of species richness and number of individuals sampled using multiple gear combinations demonstrated that appreciable benefits over relatively few gears (e.g., to four) used in optimal seasons were not present. Specifically, over 90 % of the species encountered with all gear types and season combinations (N = 19) from six lakes and reservoirs were sampled with nighttime boat electrofishing in the fall and benthic trawling, modified-fyke, and mini-fyke netting during the summer. Our results indicated that the characterization of lentic fish assemblages was highly influenced by the selection of sampling gears and seasons, but did not appear to be influenced by waterbody type (i.e., natural lake, impoundment). The standardization of data collected with multiple methods and seasons to account for bias is imperative to monitoring of lentic ecosystems and will provide researchers with increased reliability in their interpretations and decisions made using information on lentic fish assemblages. Pajuelo, J. G.; Seoane, J.; Biscoito, M.; Freitas, M.; González, J. A. The structure and composition of deep-sea fish assemblages living on the middle slope off NW Africa (26-33° N) were investigated. Data were collected by six commercial trawlers during experimental fishing (1027 hauls) at depths between 800 and 1515 m. A total of 1,115,727 fish specimens, belonging to 37 families and 96 species (24 Elasmobranchii, 5 Holocephali, and 67 Actinopteri) were collected with bottom trawls. The deep-sea demersal fish fauna off NW Africa is dominated by fishes of the family Macrouridae, followed by the Moridae and Alepocephalidae families. The main abundant species were Trachyrincus scabrus, Bathygadus favosus, Mora moro, Alepocephalus productus, Nezumia aequalis and Bathygadus melanobranchus. PERMANOVA analysis showed differences in demersal fish assemblages among bottom types, depth strata and between areas (north and south of parallel 30° N), with the area being the most influential factor followed by the type of substrate. PERMANOVAs computed separately for each area showed significant differences among the bottom types and depths in both areas. SIMPER analysis revealed that B. melanobranchus and B. favosus, which occurred at higher abundances in the area ≥30° N, were the species that were best discriminated between areas; whilst T. scabrus and M. moro occurred at higher abundances in the area <30° N. N. aequalis, B. favosus, B. melanobranchus, Deania hystricosa, Aphanopus intermedius, Coelorinchus labiatus and Halosaurus johnsonianus were restricted or more abundant in the area ≥30° N, and functioned as the discriminating species that most contributed to the average dissimilarity between areas. T. scabrus, M. moro, Alepocephalus productus and Alepocephalus bairdii were more abundant in the area <30° N. The standardized mean abundance (in number of individuals/km2) showed a decreasing pattern: i) with depth in both areas, north and south of parallel 30° N, and ii) with depth on each type of substrate, except on cold coral The role of the coastal margin and the watershed context in defining the ecology of even very large lakes is increasingly being recognized and examined. Coastal wetlands are both important contributors to the biodiversity and productivity of large lakes and important mediators of the lake-basin connection. We explored wetland-watershed connections and their relationship to wetland function and condition using data collected from 37 Lake Superior wetlands spanning a substantial geographic and geomorphic gradient. While none of these wetlands are particularly disturbed, there were nevertheless clear relationships between watershed landuse and wetland habitat and biota, and these varied consistently across wetland type categories that reflected the strength of connection to the watershed. For example, water clarity and vegetation structure complexity declined with decreasing percent natural land cover, and these effects were strongest in riverine wetlands (having generally large watersheds and tributary-dominated hydrology) and weakest in lagoon wetlands (having generally small watersheds and lake-dominate hydrology). Fish abundance and species richness both increased with decreasing percent natural land cover while species diversity decreased, and again the effect was strongest in riverine wetlands. Lagoonal wetlands, which lack any substantial tributary, consistently harbored the fewest species of fish and a composition different from the more watershed-lin Reiss, H.; Degraer, S.; Duineveld, G.C.A.; Craeymeersch, J.A.M. Understanding the structure and interrelationships of North Sea benthic invertebrate and fish communities and their underlying environmental drivers is an important prerequisite for conservation and spatial ecosystem management on scales relevant to ecological processes. Datasets of North Sea Luisa Resende Manna; Carla Ferreira Rezende The habitat use is an individual choice that is influenced by physical conditions such as substrate type, food resources availability and adequate depth. However, habitat use is often measured only through interspecific variability because intraspecific variability is supposed to be low. Here, the differences in habitat use by two stream fish assemblages in two different environments (Brazilian rainforest and semiarid) were investigated at both interspecific and intraspecific levels. We perfo... Henry L. Spach Full Text Available Annual variation in the fish assemblage characteristics on a tidal flat was studied in coastal Paraná, in southern Brazil. Fish were collected between August 1998 and July 1999, during the diurnal high tide and diurnal and nocturnal low tide of the syzygial (full moon and quadrature (waning moon tides, to characterize temporal change in assemblage composition. A total of 64,265 fish in 133 species were collected. The average number of species and individuals, biomass, species richness, diversity (mass and equitability varied significantly over time . The dissimilarity of the assemblage was greatest in August, September and October in contrast with the period from November to January, with the lowest dissimilarity. The combined action of water temperature, salinity and wind intensity had a great influence over the structure of the fish assemblage.Os peixes de uma planície de maré da praia Balneário de Pontal do Sul, Paraná, foram coletados, na preamar diurna e na baixa-mar diurna e noturna das marés de sizígia e de quadratura, visando caracterizar as mudanças temporais entre agosto de 1998 e julho de 1999. As coletas totalizaram 64.265 peixes de 133 espécies. Foram observadas diferenças significativas na captura média em número de espécies e de peixes, peso total e nos índices de riqueza, diversidade (H' peso e eqüitatividade entre os meses de coleta. A dissimilaridade da ictiofauna foi maior entre os meses de agosto, setembro e outubro em comparação com o período de novembro a janeiro. A ação combinada da temperatura da água, salinidade e intensidade do vento, influenciaram mais sobre a estrutura da assembléia de peixes. Santorelli, Sergio; Magnusson, William; Ferreira, Efrem; Caramaschi, Erica; Zuanon, Jansen; Amadio, Sidnéia Hypotheses about phylogenetic relationships among species allow inferences about the mechanisms that affect species coexistence. Nevertheless, most studies assume that phylogenetic patterns identified are stable over time. We used data on monthly samples of fish from a single lake over 10 years to show that the structure in phylogenetic assemblages varies over time and conclusions depend heavily on the time scale investigated. The data set was organized in guild structures and temporal scales... Ferreira, Fabio Cop; Souza, Ursulla Pereira; Petrere Junior2, Miguel Abstract The riparian vegetation in lakes and reservoirs is source of course wood structures such as trunks and branches and is used as sheltering, spawning and foraging habitats for fishes. The reduction of these submerged structures can thus, affect the composition and structure of fish assemblages in reservoirs. Aim To evaluate the influence of riparian vegetation on the biotic condition of fish assemblage by adapting the Reservoir Fish Assemblage Index (RFAI) to two reservoirs in the Upp... De Troch, Marleen; Reubens, Jan T; Heirman, Elke; Degraer, Steven; Vincx, Magda The construction of wind farms introduces artificial hard substrates in sandy sediments. As Atlantic cod (Gadus morhua) and pouting (Trisopterus luscus) tend to aggregate in order to feed around these reefs, energy profiling and trophic markers were applied to study their feeding ecology in a wind farm in the Belgian part of the North Sea. The proximate composition (carbohydrates, proteins and lipids) differed significantly between liver and muscle tissue but not between fish species or between their potential prey species. Atlantic cod showed to consume more energy than pouting. The latter had a higher overall energy reserve and can theoretically survive twice as long on the available energy than cod. In autumn, both fish species could survive longer on their energy than in spring. Polyunsaturated fatty acids were found in high concentrations in fish liver. The prey species Jassa and Pisidia were both rich in EPA while Jassa had a higher DHA content than Pisidia. Energy profiling supported the statement that wind farm artificial reefs are suitable feeding ground for both fish species. Sufficient energy levels were recorded and there is no indication of competition. Brown, Alastair; Thatje, Sven Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity-depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity-depth pattern over time. Thermal Work, Kirsten; Codner, Keneil; Gibbs, Melissa Freshwater bodies are increasingly affected by reductions in water quantity and quality and by invasions of exotic species. To protect water quantity and maintain the ecological integrity of many water bodies in central Florida, a program of adopting Minimum Flows and Levels (MFLs) has begun for both lentic and lotic waters. The purpose of this study was to determine whether there were relationships between discharge and stage, water quality, and biological parameters for Volusia Blue Spring, a first magnitude spring (discharge > 380,000 m 3 day -1 or 100 mgd) for which an MFL program was adopted in 2006. Over the course of fourteen years, we assessed fish density and diversity weekly, monthly, or seasonally with seine and snorkel counts. We evaluated annual changes in the assemblages for relationships with water quantity and quality. Low discharge and dissolved oxygen combined with high stage and conductivity produced a fish population with a lower density and diversity in 2014 than in previous years. Densities of fish taxonomic/functional groups also were low in 2014 and measures of water quantity were significant predictors of fish assemblage structure. As a result of the strong relationships between variation in discharge and an array of chemical and biological characteristics of the spring, we conclude that maintaining the historical discharge rate is important for preserving the ecological integrity of Volusia Blue Spring. Copyright © 2017 Elsevier Ltd. All rights reserved. Jonathan, M P; Aurioles-Gamboa, David; Villegas, Lorena Elizabeth Campos; Bohórquez-Herrera, Jimena; Hernández-Camacho, Claudia J; Sujitha, S B Concentrations of 11 trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, As, Hg) in 40 fish species from Santa Maria Bay, Baja California Sur, Mexico, the strategically important area for marine mammals and organisms were analyzed. Based on their concentrations the ranking of metals Fe>Zn>Ni>Cr>Mn>Pb>Cu>Co>As>Cd>Hg suggests that organism size, metabolism and feeding habits are correlated with metal concentrations. Local geological formations affect the concentrations of different metals in the aquatic environment and are subsequently transferred to fishes. The correlation analysis suggests that metabolism and nurturing habits impact the concentration of metals. Concentrations of Fe and Mn appear to be influenced by scavenging and absorption processes, which vary by species. The considerable variability in the metal concentrations obtained in different species underscores the importance of regular monitoring. Copyright © 2015 Elsevier Ltd. All rights reserved. Carolina Correia Siliprandi Full Text Available Morphological characters of fishes are essential to evaluate the functional structure of assemblages, being morphological differences indicative of distinct ecological and adaptive strategies. The ecomorphology using morphospaces analyzes the structure of a fish assemblage through the values of intervals between homologous points positioned in anatomical structures of organisms phylogenetically related. These intervals can be quantified by morphogeometric and multivariate analyses. Seasonally during 2013-2014, standardized images were obtained from fishes sampled in Araça Bay, São Sebastião District, Brazil, using nine fishing gears which were grouped to verify the species occurrence variation. Qualitative approach (presence/absence data was used to carry out morphological analyses. A total of 27 landmarks and semilandmarks with anatomical, ecological and taxonomical meaning were positioned in species images of the left profile. Consensus figures were made embedding the intraspecific variability. Uniform components of the shape variation (RWs were generated. To build morphospaces, the first eight RWs were considered (explain more than 95% of the total morphological variability and were defined using Convex Hull. The RWs were also used to calculate the Morphological Richness (MR, Morphological Disparity (MD and Morphogeometric Index (EMI. The MD indicates the morphospace size and showed greater values in summer (0.051 and winter (0.047 as MR, related to the higher number of species (MRsummer=7.93; MRwinter=8.65. During all the year, the Araça Bay presents high diversity of fishes. Nevertheless, winter and summer seasons reached the highest diversity, periods when horizontal mobile fishes with elongated shapes arrive to the region, implying an increase of morphological diversity and shape’s redundancy (represented by the lowest values of EMI: winter=0.120; summer=0.123. Corey B Wakefield Full Text Available Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment and modified (rockwall and dredge channel habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment. Krag, Ludvig Ahm; Holst, René; Madsen, Niels and to compare the performance of the two frames. The vertical distribution of cod in the aft end of the trawl was close to uniform, whereas haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), plaice (Pleuronectes platessa), and lemon sole (Microstomus kitt) showed more uneven distributions....... The use of guiding bars in the separator frame significantly (p lemon sole in the upper compartment. The vertical separation of cod was density-dependent; high densities of fish resulted in a more uniform distribution of cod. The species separations found... Elizabeti Y. Muto Full Text Available The temporal and spatial variations of feeding habits and trophic groups of demersal fish species of Santos Bay and the adjacent continental shelf were investigated. The samples were taken in September 2005 and March 2006 by bottom otter trawling. The stomach content analysis of 2,328 specimens of 49 species showed most fish fed on a large range of food items but relied heavily on shrimp, crabs/swimming-crabs, amphipods, mysids, polychaetes, ophiuroids, squids, and teleosteans. The species were classified into ten trophic groups. Shrimp were an important food source in the Santos bay and inner shelf, while ophiuroids were important prey for predators of the middle shelf. Many species relied on crabs/swimming-crabs during the summer, especially on the middle shelf. The spatial and temporal variability in food resource utilization by fish were related to the pattern of distribution and abundance of their prey. The predation on shrimp and crabs/swimming-crabs seems to be related to the water mass dynamics of the region. Intraspecific comparisons demonstrated that most of the species display spatial and/or temporal variation in their diet. The demersal ichtyofauna can also be divided into the more general categories of piscivores, nektonic invertebrate feeders, benthic invertebrate feeders and planktonic invertebrate feeders. Mims, Meryl C; Olden, Julian D The hydrologic regime is regarded as the primary driver of freshwater ecosystems, structuring the physical habitat template, providing connectivity, framing biotic interactions, and ultimately selecting for specific life histories of aquatic organisms. In the present study, we tested ecological theory predicting directional relationships between major dimensions of the flow regime and life history composition of fish assemblages in perennial free-flowing rivers throughout the continental United States. Using long-term discharge records and fish trait and survey data for 109 stream locations, we found that 11 out of 18 relationships (61%) tested between the three life history strategies (opportunistic, periodic, and equilibrium) and six hydrologic metrics (two each describing flow variability, predictability, and seasonality) were statistically significant (P history strategies, with 82% of all significant relationships observed supporting predictions from life history theory. Specifically, we found that (1) opportunistic strategists were positively related to measures of flow variability and negatively related to predictability and seasonality, (2) periodic strategists were positively related to high flow seasonality and negatively related to variability, and (3) the equilibrium strategists were negatively related to flow variability and positively related to predictability. Our study provides important empirical evidence illustrating the value of using life history theory to understand both the patterns and processes by which fish assemblage structure is shaped by adaptation to natural regimes of variability, predictability, and seasonality of critical flow events over broad biogeographic scales. for studies that only sample fish assemblages to evaluate aquatic ecosystem impacts. Therefore, this approach can be useful to amplify assessments of human impacts, and to incorporate additional bioindicators. Denderen, van P.D.; Kooten, van T.; Rijnsdorp, A.D. Bottom trawls are a globally used fishing gear that physically disturb the seabed and kill non-target organisms, including those that are food for the targeted fish species. There are indications that ensuing changes to the benthic invertebrate community may increase the availability of food and Miranda, Leandro E.; Bies, J. M.; Hann, D. A. Inputs of nutrients, sediments and detritus from catchments can promote selected components of reservoir fish assemblages, while hindering others. However, investigations linking these catchment subsidies to fish assemblages have generally focussed on one or a handful of species. Considering this paucity of community-level awareness, we sought to explore the association between land use and fish assemblage composition in reservoirs. To this end, we compared fish assemblages in reservoirs of two sub-basins of the Tennessee River representing differing intensities of agricultural development, and hypothesised that fish assemblage structure indicated by species percentage composition would differ among reservoirs in the two sub-basins. Using multivariate statistical analysis, we documented inter-basin differences in land use, reservoir productivity and fish assemblages, but no differences in reservoir morphometry or water regime. Basins were separated along a gradient of forested and non-forested catchment land cover, which was directly related to total nitrogen, total phosphorous and chlorophyll-a concentrations. Considering the extensive body of knowledge linking land use to aquatic systems, it is reasonable to postulate a hierarchical model in which productivity has direct links to terrestrial inputs, and fish assemblages have direct links to both land use and productivity. We observed a shift from an invertivore-based fish assemblage in forested catchments to a detritivore-based fish assemblage in agricultural catchments that may be a widespread pattern among reservoirs and other aquatic ecosystems. Henriques, Sofia; Pais, Miguel Pessanha; Costa, Maria José; Cabral, Henrique Nogueira The present study analyzed the effects of seasonal variation on the stability of fish-based metrics and their capability to detect changes in fish assemblages, which is yet poorly understood despite the general idea that guilds are more resilient to natural variability than species abundances. Three zones subject to different levels of fishing pressure inside the Arrábida Marine Protected Area (MPA) were sampled seasonally. The results showed differences between warm (summer and autumn) and cold (winter and spring) seasons, with the autumn clearly standing out. In general, the values of the metrics density of juveniles, density of invertebrate feeders and density of omnivores increased in warm seasons, which can be attributed to differences in recruitment patterns, spawning migrations and feeding activity among seasons. The density of generalist/opportunistic individuals was sensitive to the effect of fishing, with higher values at zones with the lowest level of protection, while the density of individuals with high commercial value only responded to fishing in the autumn, due to a cumulative result of both juveniles and adults abundances during this season. Overall, this study showed that seasonal variability affects structural and functional features of the fish assemblage and that might influence the detection of changes as a result of anthropogenic pressures. The choice of a specific season, during warm sea conditions after the spawning period (July-October), seems to be more adequate to assess changes on rocky-reef fish assemblages. Álvarez, Itziar; Catalán, Ignacio A.; Jordi, Antoni; Palmer, Miquel; Sabatés, Ana; Basterretxea, Gotzon The influence of coastal environmental conditions from winter-spring to summer on fish larvae assemblages in a temperate area has suggested a seasonal shift in ecosystem-level variation through which trophic pathways shift from the pelagic to the benthic system. This variation may be related to marked effects in the reproductive strategies in the fishes inhabiting the area and indirectly affect ichthyoplankton assemblages. Larval fish assemblages were sampled fortnightly at three stations located in coastal waters off southern Mallorca (Western Mediterranean) from March to August 2007, covering the main spawning period for the resident coastal fish in this region. The larval fish assemblage showed clear seasonality with higher specific abundance but lower diversity in the spring. Two main assemblages were identified: a spring assemblage, occurring at surface seawater temperatures ichthyoplankton communities occurred in early June, coinciding with the onset of summer hydrographical conditions and the local benthic productivity peak. Full Text Available The objective of this research was to estimate the potency of demersal fish resource spread over three sub-districts i.e. Sangkulirang, Sandaran and Kaliorang in Kutai district, East Kalimantan province. The result showed that the highest total biomass was produced by aquatic zone of Sandaran sub-district with 1,763,713.6 ton/zone and the density stock was 13,566.5 kg/km2. It was followed by Sangkulirang sub-district with 264,653.3 ton/zone and 6,640.4 kg/km2, respectively and then by Kaliorang sub-district with 58.086,5 ton/zone and 2,768.0 kg/km2, respectively. In term of species particularly from crustaseaae family, the most economic aquatic zone was found in Sangkulirang sub-district. The export product species Penaeus sp was obtained from Penaeus monodon, Metapenaeus monoceros, Metapenaeus sp, Parapenaeopsis sculptilis, Penaeus sp, and lobster which was accounted by 3,381.6 tons/zone, 83,199 tons/zone, 14,492.7 tons/zone, 24,691.3 tons/zone, 41,331.1 tons/zone, and 1,073.5 tons/zone, respectively. It was followed by Sandaran sub-district with export product species was Penaeus merguensis 33,495.7 tons/zone and non-export products were Parapenaeopsis sculptilis 63,641.7 tons/zone, Penaeus sp 16,747.8 tons/zone, Metapenaeus sp 1.674,8 tons/zone, Caridina sp 1.562.572,2 tons/zone, and Scylla serrata 3,349.6 tons/zone. Next was Kaliorang sub-district which accounted by Penaeus merguensis 62.2 tons/zone and Metapenaeus monoceros 49.7 tons/zone. In situ measurement on seven physical-chemical quality parameters of water which compared to the standardized of sea water showed that water quality found in coastal zone of Kaliorang, Sangkulirang and Sandaran sub-district, East Kutai province was suitable and feasible for the aquatic and living of marine habitats Normal 0 false false false IN X-NONE X-NONE Myun Park, Joo; Nam Kwak, Seok; Huh, Sung-Hoi; Han, In-Seong Dietary niches and food resource partitioning can support the coexistence of many fishes in benthic marine systems, which can lead to the greater abundances of those species that can potentially support their fisheries. Diets and niche overlap among nine demersal fish species were investigated in the southern continental shelf of East/Japan Sea, Korea. Specimens were collected monthly from January to November 2007 on soft bottoms between 40 and 100 m depth using a bottom trawl. A total of 20 prey taxa were found in 1904 stomachs of the nine species. Comparison of the stomach contents among the nine species showed that inter-specific dietary compositions differed significantly. Although all fish species consumed similar types of prey items, their contributions to the diet of different species varied. Among prey taxa, carid shrimps contributed greatly to the diets of Amblychaeturichthys hexanema, Amblychaeturichthys sciistius, Coelorinchus multispinulosus, Lepidotrigla guentheri, and Liparis tanakae, whereas polychaetes and teleosts contributed to the diets of Callionymus lunatus and Lophius litulon, respectively. On the other hand, carid shrimps and teleosts together contributed to the diets of Pseudorhombus pentophthalmus. Non-metric multivariate analysis of the mass contributions of dietary categories for food resources emphasized visually that the dietary compositions of the nine species differed. Although C. multispinulosus, L. guentheri, L. litulon, and L. tanakae showed similar dietary compositions between small and large size classes, ontogenetic diet changes of the remaining six species were evident. Feeding relationships among the nine demersal species were complicated, but inter- and intra-specific differences in dietary composition among the species reduced potential competition for food resources within the fish community in the southern continental shelf of East/Japan Sea, Korea. Full Text Available The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%. This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006 aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy Colloca, Francesco; Garofalo, Germana; Bitetto, Isabella; Facchini, Maria Teresa; Grati, Fabio; Martiradonna, Angela; Mastrantonio, Gianluca; Nikolioudakis, Nikolaos; Ordinas, Francesc; Scarcella, Giuseppe; Tserpes, George; Tugores, M Pilar; Valavanis, Vasilis; Carlucci, Roberto; Fiorentino, Fabio; Follesa, Maria C; Iglesias, Magdalena; Knittweis, Leyla; Lefkaditou, Eugenia; Lembo, Giuseppe; Manfredi, Chiara; Massutí, Enric; Pace, Marie Louise; Papadopoulou, Nadia; Sartor, Paolo; Smith, Christopher J; Spedicato, Maria Teresa The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem Jahson B. Alemu I. Full Text Available Reef fish assemblages in the Caribbean are under increasing pressure from human activities. Inadequate enforcement of legislation coupled with unreliable and data-poor landings in Tobago have led to the unregulated exploitation of reef fish for decades. This study addresses the lack of data on major reefs. Visual observations of fish fauna were conducted from November 2011-May 2013 at open access reef sites (Speyside, Charlotteville, Culloden, Arnos Vale, Mt. Irvine, La Guira, Kilgwyn, Plymouth and Black Rock and one protected area (Buccoo Reef Marine Park. Belt transects surveys were used to determine fish density, species diversity and abundance at the 10-15m depth contour. Fish sizes were converted to biomass using the length-weight relationship of fish W=aLb. Most fish assemblages were dominated by small herbivores (40cm e.g. Serranidae, were noted, which is indicative of fishing pressure. MDS ordination identified three fish assemblages: i northeastern, ii southwestern and iii intermediate. The northwestern cluster (Speyside and Charlotteville were most representative of reef fish assemblages across the entire island, and exhibited the highest species richness, diversity and biomass. However, the southwestern cluster the highest numerical abundance. The marine protected area contained higher fish biomass, abundance, diversity and richness, but it was only representative of reef fish assemblages on the southwest of the island and not the entire Tobago. Research on the reef fishery, particularly spear fishing, is recommended to determine impact. María Inés Lorenzo Full Text Available Demersal fish assemblages from trawl surveys in the Rio de la Plata estuary and its inner continental shelf were analyzed from 1975 to 1995. The first two factors of Principal Component Analysis explained 48% of the variance in species distribution, and they are consistent with the results of a cluster analysis. The analysis indicated the existence of three spatially and temporally distinct fish assemblages: internal and external estuarine and inner continental shelf (Uruguayan coastal assemblages. These assemblages were persistent considering the environmental characteristics and their species composition. Despite the changes registered in the species density during the period surveyed, the fish assemblages tend to persist over time. It was demonstrated that the assemblages can be considered as open systems and that there exists a reciprocal flow of organisms between adjacent associations. However, each assemblage showed high spatial and temporal persistence in accordance with the environmental characteristics of the system analyzed. Therefore, and according to the multispecies fisheries operating in the system, each assemblage defined could be considered a unit of management.Foram analisadas as associações dos peixes demersais provenientes de arrastos de prospecção no estuário do Rio de la Plata e sua plataforma interna no período de 1975 a 1995. Os dois primeiros fatores da Análise de Componentes Principais explicaram 48% da variância na distribuição das espécies sendo consistentes com os resultados da análise de agrupamento. Os resultados mostraram a existência de três associações de peixes espacial e temporalmente distintas: uruguaia costeira, estuarina externa e estuarina interna. Essas associações foram consistentes quanto às características ambientais e de composição de espécies. A despeito das mudanças registradas na densidade das espécies ao longo do período analisado, as associações de peixes foram Pombo, L.; Elliott, M.; Rebelo, J. E. Fish assemblage was examined for patterns in spatial and seasonal structure within an estuarine coastal lagoon, Ria de Aveiro. Two years of variation in abiotic conditions were recorded to identify factors responsible for maintaining the structure of fish assemblages. Nine sites were sampled monthly with a traditional “chincha” beach-seine net between November 1998 and October 2000. Fish abundance and biomass changed significantly between sites. Temperature was found to be the most important ... Dembkowski, Daniel J.; Miranda, Leandro E. We examined the interaction between environmental variables measured at three different scales (i.e., landscape, lake, and in-lake) and fish assemblage descriptors across a range of over 50 floodplain lakes in the Mississippi Alluvial Valley of Mississippi and Arkansas. Our goal was to identify important local- and landscape-level determinants of fish assemblage structure. Relationships between fish assemblage structure and variables measured at broader scales (i.e., landscape-level and lake-level) were hypothesized to be stronger than relationships with variables measured at finer scales (i.e., in-lake variables). Results suggest that fish assemblage structure in floodplain lakes was influenced by variables operating on three different scales. However, and contrary to expectations, canonical correlations between in-lake environmental characteristics and fish assemblage structure were generally stronger than correlations between landscape-level and lake-level variables and fish assemblage structure, suggesting a hierarchy of influence. From a resource management perspective, our study suggests that landscape-level and lake-level variables may be manipulated for conservation or restoration purposes, and in-lake variables and fish assemblage structure may be used to monitor the success of such efforts. Aurora M. Ricart Full Text Available Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomorphology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its relationship with live coral cover. Nine stations were sampled at three sites and three depths (6, 12 and 20 m around the reef, measuring fish species richness and biomass and hermatypic coral cover (at genus level. We evaluated variation in species richness, biomass and diversity of fish assemblages among sites and depths, as well as the relationship between the entire fish assemblage composition and live coral cover. The results showed that species richness and biomass were similar among sites, but differed across depths, increasing with depth. In contrast, diversity differed among sites but not among depths. Multivariate analyses indicated that fish assemblage composition differed among sites and depths in relation to changes in cover of coral of the genera Pocillopora, Porites, Pavona and Leptoseris, which dominate at different depths. The results showed that fish species richness and diversity were low at Clipperton Atoll and that, in isolated coral reefs with a low habitat heterogeneity and low human disturbance, live coral cover has a significant influence on the spatial variation of the reef fish assemblages. This study highlights the importance of coral habitat structure in shaping coral reef fish assemblages. Mwandya, Augustine W.; Gullström, Martin; Andersson, Mathias H.; Öhman, Marcus C.; Mgaya, Yunus D.; Bryceson, Ian Spatial and seasonal variations of fish assemblage composition were studied in three non-estuarine mangrove creeks of Zanzibar (Tanzania). Fish were collected monthly for one year at three sites (lower, intermediate and upper reaches) in each creek using a seine net (each haul covering 170 m 2). Density, species number and diversity of fish were all higher at sites with dense cover of macrophytes (seagrass and macroalgae) than over unvegetated sandy sites. In general, fish assemblages mainly comprised juveniles of a few abundant taxa, e.g. Mugil cephalus, Mugilidae spp. and Leiognathus equulus at sites with mud substratum and Gerres oyena, Lethrinus harak and Sillago sihama at sites dominated by macrophytes. Multivariate analyses revealed significant separations in fish assemblage composition within the two creeks where the bottom substratum differed among sites. Overall, season seemed to have little effect on density, species number, diversity index ( H') and assemblage structure of fish. Water condition variables were also relatively stable across the season, although a short-term fluctuation primarily induced by decreased salinity, occurred during the heavy rains in April and May. Fish assemblage structure was not significantly affected by any of the abiotic factors tested. However, significant regressions were found between the other fish variables and environmental variables, but since these associations were mostly species-specific and generally inconsistent, we suggest that the overall distribution patterns of fish were mainly an effect of particular substrate preferences of fish species rather than contemporary water conditions. Hitt, Nathaniel P.; Chambers, Douglas B. Mountaintop mining (MTM) affects chemical, physical, and hydrological properties of receiving streams, but the long-term consequences for fish-assemblage structure and function are poorly understood. We sampled stream fish assemblages using electrofishing techniques in MTM exposure sites and reference sites within the Guyandotte River basin, USA, during 2010–2011. We calculated indices of taxonomic diversity (species richness, abundance, Shannon diversity) and functional diversity (functional richness, functional evenness, functional divergence) to compare exposure and reference assemblages between seasons (spring and autumn) and across years (1999–2011). We based temporal comparisons on 2 sites that were sampled during 1999–2001 by Stauffer and Ferreri (2002). Exposure assemblages had lower taxonomic and functional diversity than reference assemblages or simulated assemblages that accounted for random variation. Differences in taxonomic composition between reference and exposure assemblages were associated with conductivity and aqueous Se concentrations. Exposure assemblages had fewer species, lower abundances, and less biomass than reference assemblages across years and seasons. Green Sunfish (Lepomis cyanellus) and Creek Chub (Semotilus atromaculatus) became numerically dominant in exposure assemblages over time because of their persistence and losses of other taxa. In contrast, species richness increased over time in reference assemblages, a result that may indicate recovery from drought. Mean individual biomass increased as fish density decreased and most obligate invertivores were apparently extirpated at MTM exposure sites. Effects of MTM were not related to physical-habitat conditions but were associated with water-quality variables, which may limit quality and availability of benthic macroinvertebrate prey. Simulations revealed effects of MTM that could not be attributed to random variation in fish assemblage structure. Perkin, Joshuah S; Gido, Keith B; Falke, Jeffrey A; Fausch, Kurt D; Crockett, Harry; Johnson, Eric R; Sanderson, John Groundwater pumping for agriculture is a major driver causing declines of global freshwater ecosystems, yet the ecological consequences for stream fish assemblages are rarely quantified. We combined retrospective (1950-2010) and prospective (2011-2060) modeling approaches within a multiscale framework to predict change in Great Plains stream fish assemblages associated with groundwater pumping from the United States High Plains Aquifer. We modeled the relationship between the length of stream receiving water from the High Plains Aquifer and the occurrence of fishes characteristic of small and large streams in the western Great Plains at a regional scale and for six subwatersheds nested within the region. Water development at the regional scale was associated with construction of 154 barriers that fragment stream habitats, increased depth to groundwater and loss of 558 km of stream, and transformation of fish assemblage structure from dominance by large-stream to small-stream fishes. Scaling down to subwatersheds revealed consistent transformations in fish assemblage structure among western subwatersheds with increasing depths to groundwater. Although transformations occurred in the absence of barriers, barriers along mainstem rivers isolate depauperate western fish assemblages from relatively intact eastern fish assemblages. Projections to 2060 indicate loss of an additional 286 km of stream across the region, as well as continued replacement of large-stream fishes by small-stream fishes where groundwater pumping has increased depth to groundwater. Our work illustrates the shrinking of streams and homogenization of Great Plains stream fish assemblages related to groundwater pumping, and we predict similar transformations worldwide where local and regional aquifer depletions occur. Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J. Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs. Gary D. Grossman; Robert E. Ratajczak; Maurice Crawford; Mary C. Freeman We assessed the relative importance of environmental variation, interspecific competition for space, and predator abundance on assemblage structure and microhabitat use in a stream fish assemblage inhabiting Coweeta Creek, North Carolina, USA. Our study encompassed a l0-yr time span (1983-1992) and included some of the highest and lowest flows in the last 58 years. We... Fish assemblage patterns as a tool to aid conservation in the Olifants River catchment ... Water SA. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current ... South Africa has committed to address freshwater conservation at the ... Laske, Sarah M.; Haynes, Trevor B.; Rosenberger, Amanda E.; Koch, Joshua C.; Wipfli, Mark S.; Whitman, Matthew; Zimmerman, Christian E. Surface water connectivity can influence the richness and composition of fish assemblages, particularly in harsh environments where colonisation factors and access to seasonal refugia are required for species persistence. Ghazilou, Amir; Shokri, Mohammad Reza; Gladstone, William Seasonal dynamics of coral reef fish assemblages were assessed along a gradient of potential anthropogenic disturbance in the Northern Persian Gulf. Overall, the attributes of coral reef fish assemblages showed seasonality at two different levels: seasonal changes irrespective of the magnitude of disturbance level (e.g. species richness), and seasonal changes in response to disturbance level (e.g. total abundance and assemblage composition). The examined parameters mostly belonged to the second group, but the interpretation of the relationship between patterns of seasonal changes and the disturbance level was not straightforward. The abundance of carnivorous fishes did not vary among seasons. SIMPER identified the family Nemipteridae as the major contributor to the observed spatiotemporal variations in the composition of coral reef fish assemblages in the study area. Copyright © 2015 Elsevier Ltd. All rights reserved. E James Hehre Full Text Available As the global demand for seaweed-derived products drives the expansion of seaweed farming onto shallow coral ecosystems, the effects of farms on fish assemblages remain largely unexplored. Shallow coral reefs provide food and shelter for highly diverse fish assemblages but are increasingly modified by anthropogenic activities. We hypothesized that the introduction of seaweed farms into degraded shallow coral reefs had potential to generate ecological benefits for fish by adding structural complexity and a possible food source. We conducted 210 transects at 14 locations, with sampling stratified across seaweed farms and sites adjacent to and distant from farms. At a seascape scale, locations were classified by their level of exposure to human disturbance. We compared sites where (1 marine protected areas (MPAs were established, (2 neither MPAs nor blast fishing was present (hence "unprotected", and (3 blast fishing occurred. We observed 80,186 fish representing 148 species from 38 families. The negative effects of seaweed farms on fish assemblages appeared stronger in the absence of blast fishing and were strongest when MPAs were present, likely reflecting the positive influence of the MPAs on fish within them. Species differentiating fish assemblages with respect to seaweed farming and disturbance were typically small but also included two key target species. The propensity for seaweed farms to increase fish diversity, abundance, and biomass is limited and may reduce MPA benefits. We suggest that careful consideration be given to the placement of seaweed farms relative to MPAs. Hehre, E James; Meeuwig, J J As the global demand for seaweed-derived products drives the expansion of seaweed farming onto shallow coral ecosystems, the effects of farms on fish assemblages remain largely unexplored. Shallow coral reefs provide food and shelter for highly diverse fish assemblages but are increasingly modified by anthropogenic activities. We hypothesized that the introduction of seaweed farms into degraded shallow coral reefs had potential to generate ecological benefits for fish by adding structural complexity and a possible food source. We conducted 210 transects at 14 locations, with sampling stratified across seaweed farms and sites adjacent to and distant from farms. At a seascape scale, locations were classified by their level of exposure to human disturbance. We compared sites where (1) marine protected areas (MPAs) were established, (2) neither MPAs nor blast fishing was present (hence "unprotected"), and (3) blast fishing occurred. We observed 80,186 fish representing 148 species from 38 families. The negative effects of seaweed farms on fish assemblages appeared stronger in the absence of blast fishing and were strongest when MPAs were present, likely reflecting the positive influence of the MPAs on fish within them. Species differentiating fish assemblages with respect to seaweed farming and disturbance were typically small but also included two key target species. The propensity for seaweed farms to increase fish diversity, abundance, and biomass is limited and may reduce MPA benefits. We suggest that careful consideration be given to the placement of seaweed farms relative to MPAs. Erico L. H Takahashi Full Text Available The upper Paraná River basin drains areas of intensive industry and agriculture, suffering negative impacts. The Córrego Rico flows through sugar cane fields and receives urban wastewater. The aim of this work is to describe and to compare the fish assemblage structure in Córrego Rico. Six standardized bimonthly samples were collected between August 2008 and June 2009 in seven different stretches of Córrego Rico. Fishes were collected with an experimental seine and sieves, euthanized, fixed in formalin and preserved in ethanol for counting and identification. Data were recorded for water parameters, instream habitat and riparian features within each stretch. Non-metric multidimensional scaling, species richness and diversity analysis were performed to examine spatial and seasonal variation in assemblage structure. Fish assemblage structure was correlated with instream habitat and water parameters. The fish assemblage was divided in three groups: upper, middle and lower reaches. High values of richness and diversity were observed in the upper and lower stretches due to connectivity with a small lake and Mogi Guaçu River, respectively. Middle stretches showed low values of richness and diversity suggesting that a small dam in the middle stretch negatively impacts the fish assemblage. Seasonal differences in fish assemblage structure were observed only in the lower stretches. Quist, M.C.; Hubert, W.A.; Isaak, D.J. Fish and habitat were sampled from 110 reaches in the Salt River basin (Idaho and Wyoming) during 1996 and 1997 to assess patterns in fish assemblage structure across a Rocky Mountain watershed. We identified four distinct fish assemblages using cluster analysis: (1) allopatric cutthroat trout (Oncorhynchus clarki (Richardson, 1836)); (2) cutthroat trout - brook trout (Salvelinus fontinalis (Mitchell, 1814)) - Paiute sculpin (Cottus beldingi Eigenmann and Eigenmann, 1891); (3) cutthroat trout - brown trout (Salmo trutta L., 1758) - mottled sculpin (Cottus bairdi Girard, 1850); and (4) Cyprinidae-Catostomidae. The distribution of fish assemblages was explained by thermal characteristics, stream geomorphology, and local habitat features. Reaches with allopatric cutthroat trout and the cutthroat trout - brook trout - Paiute sculpin assemblage were located in high-elevation, high-gradient streams. The other two fish assemblages were generally located in low-elevation streams. Associations between habitat gradients, locations of reaches in the watershed, and occurrence of species were further examined using canonical correspondence analysis. The results suggest that stream geomorphology, thermal conditions, and local habitat characteristics influence fish assemblage structure across a Rocky Mountain watershed, and they provide information on the ecology of individual species that can guide conservation activities. ?? 2004 NRC Canada. Miranda, L.E.; Lucas, G.M. The Mississippi Alluvial Valley between southern Illinois and southern Louisiana contains hundreds of floodplain lakes, most of which have been adversely affected by landscape modifications used to control flooding and support agriculture. We examined fish assemblages in lakes of this region to determine whether deterministic patterns developed in relation to prominent abiotic lake characteristics and to explore whether relevant abiotic factors could be linked to specific assemblage structuring mechanisms. The distributions of 14 taxa in 29 lakes were governed primarily by two gradients that contrasted assemblages in terms of lake area, lake elongation, and water clarity. The knowledge of whether a lake was clear or turbid, large or small, and long or short helped determine fish assemblage characteristics. Abiotic factors influenced fish assemblage structures, plausibly through limitations on foraging and physiological tolerances. Determinism in assemblage organization of floodplain lakes relative to recurrence in physicochemical features has been documented for unaltered rivers. Whereas the Mississippi Alluvial Valley has been subjected to vast anthropogenic disturbances and is not a fully functional floodplain river, fish assemblages in its floodplain lakes remain deterministic and organized by the underlying factors that also dictate assemblages in unaltered rivers. In advanced stages of lake aging, fish assemblages in these lakes are expected to largely include species that thrive in turbid, shallow systems with few predators and low oxygen concentrations. The observed patterns related to physical characteristics of these lakes suggest three general conservation foci, including (1) watershed management to control erosion, (2) removal of sediments or increases in water level to alleviate depth reductions and derived detriments to water physicochemistry, and (3) management of fish populations through stockings, removals, and harvest regulations. Francisco Leonardo Tejerina-Garro Full Text Available The objective of this study is to verify the existence of a seasonal pattern of variation in the fish assemblages of a tropical river using taxonomic and functional descriptors. Fish were sampled using gillnets at two sites on the Comté River, a large-sized river 254.8 km long, flowing entirely through rainforest areas of French Guiana. Samplings were conducted every other month from August 1998 to July 2000. Four types of fish assemblage descriptors were used: the species descriptor (number of individual fish of each species in the sample; the family descriptor (number of individual fish of each family in the sample; the trophic descriptor (distribution of the fish biomass in each feeding guild and the specific maximum observed size - MOS (number of individual fish in each of four classes of MOS: 300 mm. Results point out that changes in the fish assemblage are related to water level oscillations. The role of migration seems to be weak and is limited to trophic displacements characteristic of few species. In the low-water season, characterized by weak water level oscillation, fish species and families belonging to piscivorous or aquatic invertivorous guilds were predominant, whereas in the high-water season the environment is submitted to strong variations caused by fast and large water level oscillations, and the fish assemblage was characterized by species or families with an opportunistic omnivorous diet. Quist, Michael C.; Schultz, Randall D. Fish and benthic macroinvertebrate assemblages often provide insight on ecological conditions for guiding management actions. Unfortunately, land use and management legacies can constrain the structure of biotic communities such that they fail to reflect habitat quality. The purpose of this study was to describe patterns in fish and benthic macroinvertebrate assemblage structure, and evaluate relationships between biota and habitat characteristics in the Chariton River system of south-central Iowa, a system likely influenced by various potential management legacies (e.g., dams, chemical removal of fishes). We sampled fishes, benthic macroinvertebrates, and physical habitat from a total of 38 stream reaches in the Chariton River watershed during 2002-2005. Fish and benthic macroinvertebrate assemblages were dominated by generalist species tolerant of poor habitat quality; assemblages failed to show any apparent patterns with regard to stream size or longitudinal location within the watershed. Metrics used to summarize fish assemblages and populations [e.g., presence-absence, relative abundance, Index of Biotic Integrity for fish (IBIF)] were not related to habitat characteristics, except that catch rates of piscivores were positively related to the depth and the amount of large wood. In contrast, family richness of benthic macroinvertebrates, richness of Ephemeroptera, Trichoptera, and Plecoptera taxa, and IBI values for benthic macroinvertebrates (IBIBM) were positively correlated with the amount of overhanging vegetation and inversely related to the percentage of fine substrate. A long history of habitat alteration by row-crop agriculture and management legacies associated with reservoir construction has likely resulted in a fish assemblage dominated by tolerant species. Intolerant and sensitive fish species have not recolonized streams due to downstream movement barriers (i.e., dams). In contrast, aquatic insect assemblages reflected aquatic habitat, particularly Orsi, M L; Britton, J R The changes in the fish assemblage of the Capivara Reservoir, Brazil, were assessed over a 20 year period. Of 50 native fishes present in the initial samples, 27 were no longer present in the final samples, but there had been an addition of 11 invasive fishes, suggesting the occurrence of substantial shifts in fish diversity and abundance. © 2014 The Fisheries Society of the British Isles. Lynch, Abigail J.; Myers, Bonnie; Chu, Cindy; Eby, Lisa A.; Falke, Jeffrey A.; Kovach, Ryan P.; Krabbenhoft, Trevor J.; Kwak, Thomas J.; Lyons, John; Paukert, Craig P.; Whitney, James E. Climate is a critical driver of many fish populations, assemblages, and aquatic communities. However, direct observational studies of climate change impacts on North American inland fishes are rare. In this synthesis, we (1) summarize climate trends that may influence North American inland fish populations and assemblages, (2) compile 31 peer-reviewed studies of documented climate change effects on North American inland fish populations and assemblages, and (3) highlight four case studies representing a variety of observed responses ranging from warmwater systems in the southwestern and southeastern United States to coldwater systems along the Pacific Coast and Canadian Shield. We conclude by identifying key data gaps and research needs to inform adaptive, ecosystem-based approaches to managing North American inland fishes and fisheries in a changing climate. Vendel, A.L.; Bessa, F.; Alves, V.E.N.; Amorim, A.L.A.; Patrício, J.; Palma, A.R.T. Our aim was to quantify microplastic ingestion by fish assemblages in two tropical Brazilian estuaries and to evaluate whether biological and ecological factors influence the ingestion of microplastics by fish species. Of 2233 fish from both estuaries (from 69 species) examined in this study, 9% of the individuals (24 species) had microplastics in their gut contents. Microplastic ingestion occurred irrespective of fish size and functional group. The diet of fish species was analyzed based on prey items identified in the fish's full stomach contents and five feeding guilds were defined. Microplastics were common throughout all feeding guilds. Low (average ingestion values 1.06 ± 0.30 items/total fish) but widespread occurrence among estuaries also indicates proliferation of microplastic pollution. Our findings highlight the need to focus on assemblage level studies to understand the real magnitude of the problem and emphasize the urgency of mitigation measures directed at microplastic pollution in estuarine ecosystems. - Highlights: • We analyzed microplastic ingestion in 69 fish species collected along two estuaries. • Microplastic ingestion was widespread in fish assemblages in two tropical estuaries. • Microplastic ingestion was independent of fish size and fish functional groups. • Microplastics were observed in fish from five different feeding guilds. • The level of anthropogenic pressures did not influence microplastic ingestion. Wood, Chelsea L; Baum, Julia K; Reddy, Sheila M W; Trebilco, Rowan; Sandin, Stuart A; Zgliczynski, Brian J; Briggs, Amy A; Micheli, Fiorenza Variability in primary productivity and fishing pressure can shape the abundance, species composition, and diversity of marine life. Though parasites comprise nearly half of marine species, their responses to these important forces remain little explored. We quantified parasite assemblages at two spatial scales, across a gradient in productivity and fishing pressure that spans six coral islands of the Line Islands archipelago and within the largest Line Island, Kiritimati, which experiences a west-to-east gradient in fishing pressure and upwelling-driven productivity. In the across-islands data set, we found that increasing productivity was correlated with increased parasite abundance overall, but that the effects of productivity differed among parasite groups. Trophically transmitted parasites increased in abundance with increasing productivity, but directly transmitted parasites did not exhibit significant changes. This probably arises because productivity has stronger effects on the abundance of the planktonic crustaceans and herbivorous snails that serve as the intermediate hosts of trophically transmitted parasites than on the higher-trophic level fishes that are the sole hosts of directly transmitted parasites. We also found that specialist parasites increased in response to increasing productivity, while generalists did not, possibly because specialist parasites tend to be more strongly limited by host availability than are generalist parasites. After the effect of productivity was controlled for, fishing was correlated with decreases in the abundance of trophically transmitted parasites, while directly transmitted parasites appeared to track host density; we observed increases in the abundance of parasites using hosts that experienced fishing-driven compensatory increases in abundance. The within-island data set confirmed these patterns for the combined effects of productivity and fishing on parasite abundance, suggesting that our conclusions are robust Smith, C.D.; Quist, Michael C.; Hardy, R. S. Longitudinal gradients of fish assemblage and habitat structure were investigated in the Kootenai River of northern Idaho. A total of 43 500-m river reaches was sampled repeatedly with several techniques (boat-mounted electrofishing, hoop nets and benthic trawls) in the summers of 2012 and 2013. Differences in habitat and fish assemblage structure were apparent along the longitudinal gradient of the Kootenai River. Habitat characteristics (e.g. depth, substrate composition and water velocity) were related to fish assemblage structure in three different geomorphic river sections. Upper river sections were characterized by native salmonids (e.g. mountain whitefish Prosopium williamsoni), whereas native cyprinids (peamouth Mylocheilus caurinus, northern pikeminnow Ptychocheilus oregonensis) and non-native fishes (pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens) were common in the downstream section. Overall, a general pattern of species addition from upstream to downstream sections was discovered and is likely related to increased habitat complexity and additions of non-native species in downstream sections. Assemblage structure of the upper sections were similar, but were both dissimilar to the lower section of the Kootenai River. Species-specific hurdle regressions indicated the relationships among habitat characteristics and the predicted probability of occurrence and relative abundance varied by species. Understanding fish assemblage structure in relation to habitat could improve conservation efforts of rare fishes and improve management of coldwater river systems. Richard A. MacKenzie; Cailtin L. Kryss Fish were sampled from tide pools in Hawaii to determine how exotic mangroves Rhizophora mangle and the use of herbicides to chemically eradicate them are impacting tide pool fish assemblages. Ecological parameters were compared among mangrove-invaded, native vegetated, and non-vegetated tide pools before and after mangroves had been chemically... Odd Aksel Bergstad Full Text Available Halosauropsis macrochir ranked amongst the most abundant and widespread demersal fishes on the mid-Atlantic Ridge of the North Atlantic (Iceland-Azores with greatest abundance at 1700-3500 m. All sizes, ranging from 10-76 cm total length, occurred in the area without any apparent spatial pattern or depth trend. Using otolith sections displaying growth increments assumed to represent annuli, the age range recorded was 2-36 years, but most individuals were <20 years. Length and weight at age data were used to fit growth models. No differences between sexes in length and weight at age were observed. The majority of samples had a surplus of males. Diet analysis showed that H. macrochir feeds on Crustacea, Teleostei, Polychaeta, and Cephalopoda, but few prey could be identified to lower taxonomical levels. The mid-Atlantic Ridge constitutes a major portion of the North Atlantic living space of the abyssal halosaur where it completes its full life cycle, primarily as an actively foraging euryophagous micronekton/epibenthos and infauna feeder, becoming a partial piscivore with increasing size. Full Text Available The distribution patterns of fish assemblages within streams can provide insights for river type classifications and may warrant specific conservation actions. However, there is limited knowledge of how fish assemblages assort along a longitudinal axis in Mediterranean intermittent streams. Patterns in spatial and temporal distribution of fish communities were analysed in a Mediterranean intermittent river (Evrotas River located in Southern Greece, hosting three endemic range restricted species of high conservation concern, during the period 2007−2009, with 80% of the river’s total length desiccating in the 2007 and 2008 droughts. The general trend was an increase in fish density and species richness along an upstream-downstream gradient. Fish assemblages from upstream to downstream were characterized by a decrease of the most rheophilic species (Squalius keadicus and an increase of the most stagnophilic species (Tropidophoxinellus spartiaticus. Three river segments, characterized by a high degree of homogeneity were delineated. Habitat and environmental preferences for the studied fish species were identified, with elevation and low flowing habitats being the most important environmental factors affecting fish distribution patterns. The current study provides evidence that even in an intermittent river an assemblage pattern following a longitudinal gradient can be identified, mainly due to the lack of instream barriers that allows recolonization after flow resumption. Kirsch, Joseph; Peterson, James T. There is considerable uncertainty about the relative roles of stream habitat and landscape characteristics in structuring stream-fish assemblages. We evaluated the relative importance of environmental characteristics on fish occupancy at the local and landscape scales within the upper Little Tennessee River basin of Georgia and North Carolina. Fishes were sampled using a quadrat sample design at 525 channel units within 48 study reaches during two consecutive years. We evaluated species–habitat relationships (local and landscape factors) by developing hierarchical, multispecies occupancy models. Modeling results suggested that fish occupancy within the Little Tennessee River basin was primarily influenced by stream topology and topography, urban land coverage, and channel unit types. Landscape scale factors (e.g., urban land coverage and elevation) largely controlled the fish assemblage structure at a stream-reach level, and local-scale factors (i.e., channel unit types) influenced fish distribution within stream reaches. Our study demonstrates the utility of a multi-scaled approach and the need to account for hierarchy and the interscale interactions of factors influencing assemblage structure prior to monitoring fish assemblages, developing biological management plans, or allocating management resources throughout a stream system. Fabio Cop Ferreira Full Text Available Abstract The riparian vegetation in lakes and reservoirs is source of course wood structures such as trunks and branches and is used as sheltering, spawning and foraging habitats for fishes. The reduction of these submerged structures can thus, affect the composition and structure of fish assemblages in reservoirs. Aim To evaluate the influence of riparian vegetation on the biotic condition of fish assemblage by adapting the Reservoir Fish Assemblage Index (RFAI to two reservoirs in the Upper Paranapanema river basin, São Paulo State, Brazil. Methods The RFAI was adapted from metrics related to the functional characteristics and composition of fish assemblages through a protocol of metric selection and validation, and to its response to the presence of riparian vegetation. Results The final RFAI was composed by nine metrics, been lower in sites without riparian vegetation as consequence of the predominance of larger individuals and the percent of piscivorous and detritivorous fishes. Conclusions These results suggest that increasing shore habitat complexity in reservoirs by maintaining riparian vegetation increases fish biotic integrity. Jørgensen, Ole A; Hvingel, Carsten; Møller, P.R. During 2006 and 2008 two bottom trawl surveys were conducted at East Greenland to 72°N covering depths down to 1500 m. In the 149 trawl hauls in total 113 fish species were recorded of which 37 were considered pelagic and excluded from the analyses. As a first step the abundance data for the 76...... benthic species were used for analyses of the fish fauna diversity and fish assemblages. Nine assemblages were found by a standard type of cluster analysis. A Bayesian multinomial logit model was then applied to calculate vectors of probabilities defining the likelihood of each haul belonging to each...... distribution, species composition, temperature and depth. Three of the assemblages were located in the cold Iceland Sea while six were found in the somewhat warmer Irminger Sea... Full Text Available The effects of environmental parameters on changes in the structure of fish assemblages were studied in the Elbe and the Odra basin. Research was done at 819 sites surveyed in the field during the period 1993-2007. The impact of 46 factors derived from the maps through a GIS was tested as well as the impact of 10 factors recognized in the field. To evaluate the influence of these factors the indirect (DCA and direct (CCA multivariate cluster analysis were used. Analyses were performed with data on presence-absence and relative abundance of each species. DCA well reflects changes in assemblages in the longitudinal profile of streams. CCA refers to a significant influence of regional and temporal variability and influence of individual factors. The fish assemblages are best characterized by distance from the source location, stream slope, altitude of locality, representation of arable land in the basin, number of ponds in the sub-basin above the locality, type of waters (salmonid or cyprinid, and water temperature (the only of the parameters of the field. The analyzed factors better reflect the variability in fish assemblages of the Odra than of Elbe river basin. The analysis showed good practical efficiency of processing information from a large sample of data from ichthyological surveys. The tools of GIS and the use of statistical methods make possible to characterize basic ecological requirements of most species and specify conditions determining specific composition of fish assemblages. Raines, C. D.; Miranda, Leandro E. Research into the effects of shade on reservoir fish assemblages is lacking, with most investigations focused on streams. Unlike many streams, the canopy in a reservoir shades only a narrow fringe of water adjacent to the shoreline, and may not have the influential effect on the aquatic environment reported in streams. We compared fish assemblages between shaded and unshaded sites in a shallow reservoir. Overall species richness (gamma diversity) was higher in shaded sites, and fish assemblage composition differed between shaded and unshaded sites. Average light intensity was 66 % lower in shaded sites, and differences in average temperature and dissolved oxygen were small. Unlike streams where shade can have large effects on water physicochemistry, in reservoirs shade-related differences in fish assemblages seemed to be linked principally to differences in light intensity. Diversity in light intensity in shaded and unshaded sites in reservoirs can create various mosaics of light-based habitats that enable diversity of species assemblages. Managing to promote the habitat diversity provided by shade may require coping with the artificial nature of reservoir riparian zones and water level fluctuations. Euan S Harvey Full Text Available Distributions of mobile animals have been shown to be heavily influenced by habitat and climate. We address the historical and contemporary context of fish habitats within a major zootone: the Recherche Archipelago, southern western Australia. Baited remote underwater video systems were set in nine habitat types within three regions to determine the species diversity and relative abundance of bony fishes, sharks and rays. Constrained ordinations and multivariate prediction and regression trees were used to examine the effects of gradients in longitude, depth, distance from islands and coast, and epibenthic habitat on fish assemblage composition. A total of 90 species from 43 families were recorded from a wide range of functional groups. Ordination accounted for 19% of the variation in the assemblage composition when constrained by spatial and epibenthic covariates, and identified redundancy in the use of distance from the nearest emergent island as a predictor. A spatial hierarchy of fourteen fish assemblages was identified using multivariate prediction and regression trees, with the primary split between assemblages on macroalgal reefs, and those on bare or sandy habitats supporting seagrass beds. The characterisation of indicator species for assemblages within the hierarchy revealed important faunal break in fish assemblages at 122.30 East at Cape Le Grand and subtle niche partitioning amongst species within the labrids and monacanthids. For example, some species of monacanthids were habitat specialists and predominantly found on seagrass (Acanthaluteres vittiger, Scobinichthys granulatus, reef (Meuschenia galii, Meuschenia hippocrepis or sand habitats (Nelusetta ayraudi. Predatory fish that consume molluscs, crustaceans and cephalopods were dominant with evidence of habitat generalisation in reef species to cope with local disturbances by wave action. Niche separation within major genera, and a sub-regional faunal break, indicate future Abdul Wahab, Muhammad Azmi; Radford, Ben; Cappo, Mike; Colquhoun, Jamie; Stowar, Marcus; Depczynski, Martial; Miller, Karen; Heyward, Andrew Submerged reef ecosystems can be very diverse and may serve as important refugia for shallow-water conspecifics. This study quantified the benthic and fish communities of two proximate, predominantly mesophotic coral ecosystems (MCEs), Glomar Shoal and Rankin Bank, which are geographically isolated from other similar features in the region. Glomar Shoal is identified as a key ecological feature (KEF) in the North West Marine Region of Australia. Multibeam surveys were performed to characterise the seafloor and to derive secondary environmental variables, used to explain patterns in benthic and fish communities. Towed video surveys quantified benthic cover, and stereo baited remote underwater stations were used to survey fish abundance and diversity. Surveys were completed in depths of 20-115 m. The two MCEs exhibited distinct communities; Rankin Bank consistently had higher cover (up to 30×) of benthic taxa across depths, and fish communities that were twice as abundant and 1.5× more diverse than Glomar Shoal. The location of the MCEs, depth and rugosity were most influential in structuring benthic communities. Phototrophic taxa, specifically macroalgae and hard corals, had up to 22 × higher cover at Rankin Bank than at Glomar Shoal and were dominant to 80 m (compared to 60 m at Glomar Shoal), presumably due to greater light penetration (lower turbidity) and lower sand cover at greater depths. The 20% coral cover at Rankin Bank was comparable to that reported for shallow reefs. The cover of sand, hard corals and sponges influenced fish communities, with higher abundance and diversity of fish associated with shallow hard coral habitats. This study demonstrated that the two MCEs were unique within the local context, and when coupled with their geographical isolation and biodiversity, presents compelling support for the additional recognition of Rankin Bank as a KEF. Simier, M.; Blanc, L.; Aliaume, C.; Diouf, P. S.; Albaret, J. J. As a consequence of the Sahelian drought, the Sine Saloum, a large estuarine system located in Senegal (West Africa), has become an "inverse estuary" since the late sixties, i.e. salinity increases upstream and reaches 100 in some places. To study the fish assemblages of such a modified system, a survey was conducted in 1992, collecting fish every two months with a purse seine at eight sites spread over the three main branches of the estuary. A total of 73 species belonging to 35 families were identified. Eight species comprised 97% of the total numbers of fish. The predominant species was a small clupeid, Sardinella maderensis, representing more than half of the total biomass and nearly 70% of the total number of fish. The spatio-temporal structure of the fish assemblages was studied using the STATIS-CoA method, which combines the multitable approach with the correspondence analysis method. Whatever the season, a strong spatial organization of fish assemblages was observed, mainly related to depth and salinity. Three types of assemblages were identified. In shallow water areas, fish assemblages were dominated by Mugilidae, Gerreidae and Cichlidae and were stable with time. In open water areas, large fluctuations in the species composition were observed, due to the occasional presence of large schools of pelagic species: in the southern area, where salinity and water transparency were the lowest, the main species were Ilisha africana, Brachydeuterus auritus and Chloroscombrus chrysurus, associated with a few Sciaenidae and Tetraodontidae, while the poorest areas were characterized by only two dominant species, S. maderensis and Scomberomorus tritor. Igor David da Costa Full Text Available Abstract: Aim We investigate the influence of luminosity, habitat conservation and pluviometric periods in fish assemblages of in pasture and forest small streams in western amazon. Methods Sampling was conducted every two months from July 2013 to April 2014 in nine first- and second-order streams using seine nets and dip nets during the day and night. Fish composition, richness and total abundance were determined for each sampling period. The PERMANOVA was used to evaluate the effects of land use, season, and photoperiod, on fish assemblages. Fish assemblage structure for each stream in the presence and absence of photoperiod was ordered by NMDS analysis. Results In the light period, 3,484 specimens from 69 species were collected, while 4,574 specimens from 71 species where collected in the dark period. No significant differences in abundance and species richness were recorded between the presence and absence of luminosity periods, rainy and dry seasons and streams in forest and deforested areas. We found evidence of the dark phase composition and richness of exclusive species (22% of species collected were found at night, which were greater than in the light period (20% of species. Conclusion Despite our failure to identify any nycterohemeral segregation, the results complement existing knowledge of regional ichthyofauna and help provide a better understanding of the distributional, behavioral and functional ecological patterns of fish assemblages. Full Text Available Marine protected areas (MPAs were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS and thermophilic species (ThS is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1 MPAs are numerous, 2 fishing has affected species and ecosystems, and 3 the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP, partially-protected MPAs (IP and fished areas (F at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators, but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide. Guidetti, Paolo; Baiata, Pasquale; Ballesteros, Enric; Di Franco, Antonio; Hereu, Bernat; Macpherson, Enrique; Micheli, Fiorenza; Pais, Antonio; Panzalis, Pieraugusto; Rosenberg, Andrew A.; Zabala, Mikel; Sala, Enric Marine protected areas (MPAs) were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS) and thermophilic species (ThS) is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1) MPAs are numerous, 2) fishing has affected species and ecosystems, and 3) the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP), partially-protected MPAs (IP) and fished areas (F) at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators), but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide. PMID:24740479 Weaver, D.; Kwak, Thomas J. Fisheries managers are faced with the challenge of balancing the management of recreational fisheries with that of conserving native species and preserving ecological integrity. The negative effects that nonnative trout species exert on native trout are well documented and include alteration of competitive interactions, habitat use, and production. However, the effects that nonnative trout may exert on nongame fish assemblages are poorly understood. Our objectives were to quantify the effects of trout stocking on native nongame fish assemblages intensively on one newly stocked river, the North Toe River, North Carolina, and extensively on other southern Appalachian Mountain streams that are annually stocked with trout. In the intensive study, we adopted a before-after, control-impact (BACI) experimental design to detect short-term effects on the nongame fish assemblage and found no significant differences in fish density, species richness, species diversity, or fish microhabitat use associated with trout stocking. We observed differences in fish microhabitat use between years, however, which suggests there is a response to environmental changes, such as the flow regime, which influence available habitat. In the extensive study, we sampled paired stocked and unstocked stream reaches to detect long-term effects from trout stocking; however, we detected no differences in nongame fish density, species richness, species diversity, or population size structure between paired sites. Our results revealed high inherent system variation caused by natural and anthropogenic factors that appear to overwhelm any acute or chronic effect of stocked trout. Furthermore, hatchery-reared trout may be poor competitors in a natural setting and exert a minimal or undetectable impact on native fish assemblages in these streams. These findings provide quantitative results necessary to assist agencies in strategic planning and decision making associated with trout fisheries, stream Gomes, L.C.; Bulla, C. K.; Agostinho, A. A.; Vasconcelos, L. P.; Miranda, Leandro E. The presence of aquatic macrophytes is a key factor in the selection of habitats by fish in floodplain lakes because these plants enhance the physical and biological complexities of aquatic habitats. The seasonal flood pulse may influence this interaction, but there is no information in the literature about the effects that flood events may have on macrophytes assemblages and its associated effects on fish assemblages. Thus, this article aimed to investigate whether species richness, evenness and similarities in fish assemblage composition differed between littoral areas vegetated with macrophytes and unvegetated areas, before and after a flood. We sampled three lakes in the floodplain of the upper Paraná River basin. Sampling was conducted before (December 2004 and January 2005) and after (early March, late March and May 2005) a flood event. Overall, species richness and evenness were higher in macrophytes-covered areas. Before the flood, the composition of fish assemblages was distinct when comparing vegetated and unvegetated areas. After the flood, the similarity in fish assemblage composition was higher, indicating a homogenization effect of floods for fish inhabiting littoral areas of floodplain lakes. After the flood, opportunistic species dominated the fish assemblages in aquatic macrophytes, apparently restructuring assemblages in the littoral, restarting a succession process. Thus, the observed homogenization effect of the flood could minimize biological interactions and could induce fish assemblages to begin a new process of structurization. Ansari, Z.A.; Chatterji, A.; Ingole, B.S.; Sreepada, R.A.; Rivonker, C.U.; Parulekar, A.H. as an environment for nekton. Fish Community Ecology in Estuaries aud Coastal Lagoons: Towards an Ecosystem Integration (Yanez-Arancibia, A., ed.). DR(R) UNAM Press Mexico, Mexico City, pp. 17-34. Fisher, W. & Biachi, G. 1984 FAO Species Indenttjkation Sheets... Richard D Pillans Full Text Available Off the Ningaloo coast of North West Western Australia, Spangled Emperor Lethrinus nebulosus are among the most highly targeted recreational fish species. The Ningaloo Reef Marine Park comprises an area of 4,566 km2 of which 34% is protected from fishing by 18 no-take sanctuary zones ranging in size from 0.08-44.8 km2. To better understand Spangled Emperor movements and the adequacy of sanctuary zones within the Ningaloo Reef Marine Park for this species, 84 Spangled Emperor of a broad spectrum of maturity and sex were tagged using internal acoustic tags in a range of lagoon and reef slope habitats both inside and adjacent to the Mangrove Bay Sanctuary zone. Kernel Utilisation Distribution (KUD was calculated for 39 resident individuals that were detected for more than 30 days. There was no relationship with fish size and movement or site fidelity. Average home range (95% KUD for residents was 8.5±0.5 km2 compared to average sanctuary zone size of 30 km2. Calculated home range was stable over time resulting in resident animals tagged inside the sanctuary zone spending ∼80% of time within the sanctuary boundaries. The number of fish remaining within the array of receivers declined steadily over time and after one year more than 60% of tagged fish had moved outside the sanctuary zone and also beyond the 28 km2 array of receivers. Long term monitoring identified the importance of shifting home range and was essential for understanding overall residency within protected areas and also for identifying spawning related movements. This study indicates that despite exhibiting stable and small home ranges over periods of one to two years, more than half the population of spangled emperor move at scales greater than average sanctuary size within the Ningaloo Reef Marine Park. Pierce, Clay; Nicholas L. Ahrens,; Anna K. Loan-Wilsey,; Gregory A. Simmons,; Gregory T. Gelwicks, Fish assemblages in rivers of the Midwestern United States are an important component of the region's natural resources and biodiversity. We characterized the physical environment and presence of dams in a series of reaches in three eastern Iowa rivers tributary to the Mississippi River and related these characteristics to the fish assemblages present. Some physical characteristics were similar among the 12 study reaches, whereas others differed substantially. We found a total of 68 species across the 12 study reaches; 56 in the Turkey River, 51 in the Maquoketa River and 50 in the Wapsipinicon River. Seventeen species could be described as ‘downstream-distributed’; 15 being found only in the lowest reach of one or more rivers and the other two being found only in the lowest reaches or two or more contiguous reaches including the lowest reach. Two species could be described as ‘upstream-distributed’, being found only in an uppermost reach. Non-metric multidimensional scaling ordination illustrated similarities among reaches, and five physical variables were significantly correlated with assemblage similarities. Catchment area and number of dams between reaches and the Mississippi River were strongly correlated with assemblage similarities, but the directions of their effects were opposite. Catchment area and number of dams were confounded. The collective evidence to date suggests that the pervasiveness of dams on rivers significantly alters fish assemblages, making underlying patterns of species change and relationships with naturally varying and human-influenced physical characteristics along a river's course difficult to discern. Medeiros, Aline Paiva Morais de; Xavier, Josias Henrique de Amorim; Rosa, Ierecê Maria de Lucena ABSTRACT The present work aims to characterize a fish assemblage from a northeastern Brazilian estuary according to its diet and trophic organization along the estuarine-reef gradient. Sampling was performed at the Mamanguape Estuary, and fishes were collected using three types of nets at seventeen sites, grouped into four regions according to salinity range: reefs and the lower, middle, and upper estuary. The most abundant species were Atherinella brasiliensis, Mugil curema, and Sphoeroides ... Full Text Available Saba Bank is a 2,200 km(2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km(2 area of the bank for an exploratory study. Habitat and reef fish assemblages were investigated in five shallow-water benthic habitat types that form a gradient from Saba Bank shelf edge to lagoon. Significant coral cover was restricted to fore reef habitat (average cover 11.5% and outer reef flat habitat (2.4% and declined to near zero in habitats of the central lagoon zone. Macroalgae dominated benthic cover in all habitats (average cover: 32.5--48.1% but dominant algal genera differed among habitats. A total of 97 fish species were recorded. The composition of Saba Bank fish assemblages differed among habitat types. Highest fish density and diversity occurred in the outer reef flat, fore reef and inner reef flat habitats. Biomass estimates for commercially valued species in the reef zone (fore reef and reef flat habitats ranged between 52 and 83 g/m(2. The composition of Saba Bank fish assemblages reflects the absence of important nursery habitats, as well as the effects of past fishing. The relatively high abundance of large predatory fish (i.e. groupers and sharks, which is generally considered an indicator of good ecosystem health for tropical reef systems, shows that an intact trophic network is still present on Saba Bank. Peter C Jacobson Full Text Available Eutrophication and climate warming are profoundly affecting fish in many freshwater lakes. Understanding the specific effects of these stressors is critical for development of effective adaptation and remediation strategies for conserving fish populations in a changing environment. Ecological niche models that incorporated the individual effects of nutrient concentration and climate were developed for 25 species of fish sampled in standard gillnet surveys from 1,577 Minnesota lakes. Lake phosphorus concentrations and climates were hindcasted to a pre-disturbance period of 1896-1925 using existing land use models and historical temperature data. Then historical fish assemblages were reconstructed using the ecological niche models. Substantial changes were noted when reconstructed fish assemblages were compared to those from the contemporary period (1981-2010. Disentangling the sometimes opposing, sometimes compounding, effects of eutrophication and climate warming was critical for understanding changes in fish assemblages. Reconstructed abundances of eutrophication-tolerant, warmwater taxa increased in prairie lakes that experienced significant eutrophication and climate warming. Eutrophication-intolerant, warmwater taxa abundance increased in forest lakes where primarily climate warming was the stressor. Coolwater fish declined in abundance in both ecoregions. Large changes in modeled abundance occurred when the effects of both climate and eutrophication operated in the same direction for some species. Conversely, the effects of climate warming and eutrophication operated in opposing directions for other species and dampened net changes in abundance. Quantifying the specific effects of climate and eutrophication will allow water resource managers to better understand how lakes have changed and provide expectations for sustainable fish assemblages in the future. Cooney, Patrick B.; Kwak, Thomas J. Habitat connectivity is vital to the persistence of migratory fishes. Native tropical island stream fish assemblages composed of diadromous species require intact corridors between ocean and riverine habitats. High dams block fish migration, but low-head artificial barriers are more widespread and are rarely assessed for impacts. Among all 46 drainages in Puerto Rico, we identified and surveyed 335 artificial barriers that hinder fish migration to 74.5% of the upstream habitat. We also surveyed occupancy of native diadromous fishes (Anguillidae, Eleotridae, Gobiidae, and Mugilidae) in 118 river reaches. Occupancy models demonstrated that barriers 2 meters (m) high restricted nongoby fish migration and extirpated those fish upstream of 4-m barriers. Gobies are adapted to climbing and are restricted by 12-m barriers and extirpated upstream of 32-m barriers. Our findings quantitatively illustrate the extensive impact of low-head structures on island stream fauna and provide guidance for natural resource management, habitat restoration, and water development strategies. Fish resources found in waters of Malacca Strait consist of shrimp, demersal ﬁsh, large pelagic ﬁsh and small pelagic ﬁsh resources. Exploitation of demersal resources in the waters of Malacca Strait is very intensive. Therefore this study was aims to determine the development of the composition of demersal ﬁsh in the waters of Malacca Straits. The study was conducted in the waters of Malacca Straits that focused around Belawan and Bengkalis, which was held in June 2008, using the KR. Bawal P... Meador, Michael R.; Carlisle, Daren M. Although altered streamflow has been implicated as a major factor affecting fish assemblages, understanding the extent of streamflow alteration has required quantifying attributes of the natural flow regime. We used predictive models to quantify deviation from expected natural streamflow variability for streams in the eastern USA. Sites with >25% change in mean daily streamflow variability compared with what would be expected in a minimally disturbed environment were defined as having altered streamflow variability, based on the 10th and 90th percentiles of the distribution of streamflow variability at 1279 hydrological reference sites. We also used predictive models to assess fish assemblage condition and native species loss based on the proportion of expected native fish species that were observed. Of the 97 sites, 49 (50.5%) were classified as altered with reduced streamflow variability, whereas no sites had increased streamflow variability. Reduced streamflow variability was related to a 35% loss in native fish species, on average, and a >50% loss of species with a preference for riffle habitats. Conditional probability analysis indicated that the probability of fish assemblage impairment increased as the severity of altered streamflow variability increased. Reservoir storage capacity and wastewater discharges were important predictors of reduced streamflow variability as revealed by random forest analysis. Management and conservation of streams will require careful consideration of natural streamflow variation and potential factors contributing to altered streamflow within the entire watershed to limit the loss of critical stream habitats and fish species uniquely adapted to live in those habitats. D'Ambrosio, Jessica L; Williams, Lance R; Witter, Jonathan D; Ward, Andy In this paper, we evaluate relationships between in-stream habitat, water chemistry, spatial distribution within a predominantly agricultural Midwestern watershed and geomorphic features and fish assemblage attributes and abundances. Our specific objectives were to: (1) identify and quantify key environmental variables at reach and system wide (watershed) scales; and (2) evaluate the relative influence of those environmental factors in structuring and explaining fish assemblage attributes at reach scales to help prioritize stream monitoring efforts and better incorporate all factors that influence aquatic biology in watershed management programs. The original combined data set consisted of 31 variables measured at 32 sites, which was reduced to 9 variables through correlation and linear regression analysis: stream order, percent wooded riparian zone, drainage area, in-stream cover quality, substrate quality, gradient, cross-sectional area, width of the flood prone area, and average substrate size. Canonical correspondence analysis (CCA) and variance partitioning were used to relate environmental variables to fish species abundance and assemblage attributes. Fish assemblages and abundances were explained best by stream size, gradient, substrate size and quality, and percent wooded riparian zone. Further data are needed to investigate why water chemistry variables had insignificant relationships with IBI scores. Results suggest that more quantifiable variables and consideration of spatial location of a stream reach within a watershed system should be standard data incorporated into stream monitoring programs to identify impairments that, while biologically limiting, are not fully captured or elucidated using current bioassessment methods. Jurajda, Pavel; Roche, Kevin Francis; Sedláček, I.; Všetičková, Lucie Roč. 39, č. 12 (2016), s. 2299-2309 ISSN 0722-4060 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Antarctic Peninsula * Fish assemblage structure * Notothenioidei * Shallow coastal waters * Ice pack * Czech Antarctic Station Subject RIV: EH - Ecology, Behaviour Impact factor: 1.949, year: 2016 Ruttenberg, B.I.; Hamilton, S.L.; Walsh, S.M.; Donovan, M.K.; Friedlander, A.; DeMartini, E.; Sala, E.; Sandin, S.A. In recent years, it has become apparent that human impacts have altered community structure in coastal and marine ecosystems worldwide. Of these, fishing is one of the most pervasive, and a growing body of work suggests that fishing can have strong effects on the ecology of target species, especially top predators. However, the effects of removing top predators on lower trophic groups of prey fishes are less clear, particularly in highly diverse and trophically complex coral reef ecosystems. We examined patterns of abundance, size structure, and age-based demography through surveys and collection-based studies of five fish species from a variety of trophic levels at Kiritimati and Palmyra, two nearby atolls in the Northern Line Islands. These islands have similar biogeography and oceanography, and yet Kiritimati has ~10,000 people with extensive local fishing while Palmyra is a US National Wildlife Refuge with no permanent human population, no fishing, and an intact predator fauna. Surveys indicated that top predators were relatively larger and more abundant at unfished Palmyra, while prey functional groups were relatively smaller but showed no clear trends in abundance as would be expected from classic trophic cascades. Through detailed analyses of focal species, we found that size and longevity of a top predator were lower at fished Kiritimati than at unfished Palmyra. Demographic patterns also shifted dramatically for 4 of 5 fish species in lower trophic groups, opposite in direction to the top predator, including decreases in average size and longevity at Palmyra relative to Kiritimati. Overall, these results suggest that fishing may alter community structure in complex and non-intuitive ways, and that indirect demographic effects should be considered more broadly in ecosystem-based management. ?? 2011 Ruttenberg et al. Benjamin I Ruttenberg Full Text Available In recent years, it has become apparent that human impacts have altered community structure in coastal and marine ecosystems worldwide. Of these, fishing is one of the most pervasive, and a growing body of work suggests that fishing can have strong effects on the ecology of target species, especially top predators. However, the effects of removing top predators on lower trophic groups of prey fishes are less clear, particularly in highly diverse and trophically complex coral reef ecosystems. We examined patterns of abundance, size structure, and age-based demography through surveys and collection-based studies of five fish species from a variety of trophic levels at Kiritimati and Palmyra, two nearby atolls in the Northern Line Islands. These islands have similar biogeography and oceanography, and yet Kiritimati has ∼10,000 people with extensive local fishing while Palmyra is a US National Wildlife Refuge with no permanent human population, no fishing, and an intact predator fauna. Surveys indicated that top predators were relatively larger and more abundant at unfished Palmyra, while prey functional groups were relatively smaller but showed no clear trends in abundance as would be expected from classic trophic cascades. Through detailed analyses of focal species, we found that size and longevity of a top predator were lower at fished Kiritimati than at unfished Palmyra. Demographic patterns also shifted dramatically for 4 of 5 fish species in lower trophic groups, opposite in direction to the top predator, including decreases in average size and longevity at Palmyra relative to Kiritimati. Overall, these results suggest that fishing may alter community structure in complex and non-intuitive ways, and that indirect demographic effects should be considered more broadly in ecosystem-based management. A trophic study was carried out in February of 2012 to January 2013 on the ecosystem in the Persian Gulf, Bushehr provience. A total of 2,948 samples of stomach contents were analyzed based on the weight and number of food items and were identified about 40 preys. Crustacean and bony fish were as a main prey in most of the stomach contents . The mean average trophic level was estimated at 3.6 by Ecopath software. In this research, the mean level were studied between eight species varied fr... Jorgensen, Salvador J; Klimley, A Peter; Muhlia-Melo, Arturo; Morgan, Steven G Seamounts have generally been identified as locations that can promote elevated productivity, biomass and predator biodiversity. These properties attract seamount-associated fisheries where elevated harvests can be obtained relative to surrounding areas. There exists large variation in the geological and oceanographic environment among the thousands of locations that fall within the broad definition of seamount. Global seamount surveys have revealed that not all seamounts are hotspots of biodiversity, and there remains a strong need to understand the mechanisms that underlie variation in species richness observed. We examined the process of fish species assembly at El Bajo Espiritu Santo (EBES) seamount in the Gulf of California over a five-year study period. To effectively quantify the relative abundance of fast-moving and schooling fishes in a 'blue water' habitat, we developed a simplified underwater visual census (UVC) methodology and analysis framework suitable for this setting and applicable to future studies in similar environments. We found correlations between seasonally changing community structure and variability in oceanographic conditions. Individual species responses to thermal habitat at EBES revealed three distinct assemblages, a 'fall assemblage' tracking warmer overall temperature, a 'spring assemblage' correlated with cooler temperature, and a 'year-round assemblage' with no significant response to temperature. Species richness was greatest in spring, when cool and warm water masses stratified the water column and a greater number of species from all three assemblages co-occurred. We discuss our findings in the context of potential mechanisms that could account for predator biodiversity at shallow seamounts. María Eugenia Vega-Cendejas Full Text Available Fish assemblage structure was evaluated and compared among 36 karstic pools located within protected areas of the Calakmul Biosphere Reserve (southern Mexico and unprotected adjacent areas beyond the Reserve. Nonmetric multidimensional scaling (MDS, indicator species analysis (ISA, and canonical correspondence analysis (CCA were used to identify which environmental factors reflected local influences and to evaluate the correlation of these variables with fish assemblages structure. Thirty-one species were encountered in these karstic pools, some for the first time within the Reserve. These aquatic environments were separated into three groups based on physico-chemical characteristics. Although CCA identified significant associations between several fish species (based on their relative abundance and environmental variables (K, NH4, NO3, and conductivity, the most abundant species (Astyanax aeneus, Poecilia mexicana, and Gambusia sexradiata occur in most pools and under several environmental conditions. Baseline data on fish diversity along with a continued monitoring program are essential in order to evaluate the conservation status of fish assemblages and their habitats, as well as to measure the influence of anthropogenic impacts on pristine habitats such as the karstic pools of the Calakmul Biosphere Reserve. Carmen G. Montaña Full Text Available Morichales are lowland streams in South American savannas with riparian forest dominated by the moriche palm (Mauritia flexuosa. We sampled littoral habitats from ten flooded vegetated patches (dominated by Mauritiella aculeate and six sand banks in two months of the dry season (Feb-Mar 2005 in a stream in the savannas of Apure State, Venezuela. We collected samples that compromised 12,407 individual fishes of 107 species. Small-bodied fishes (< 100 mm, representing diverse trophic and life history strategies, were abundant. The most abundant species were in the families Characidae and Cichlidae. Fish assemblages from flooded vegetated patches differed significantly from those on adjacent sand banks. High structural complexity along vegetated shoreline habitats of morichal streams likely contributes to species richness and affects assemblage composition. Galaiduk, Ronen; Radford, Ben T; Wilson, Shaun K; Harvey, Euan S Information on habitat associations from survey data, combined with spatial modelling, allow the development of more refined species distribution modelling which may identify areas of high conservation/fisheries value and consequentially improve conservation efforts. Generalised additive models were used to model the probability of occurrence of six focal species after surveys that utilised two remote underwater video sampling methods (i.e. baited and towed video). Models developed for the towed video method had consistently better predictive performance for all but one study species although only three models had a good to fair fit, and the rest were poor fits, highlighting the challenges associated with modelling habitat associations of marine species in highly homogenous, low relief environments. Models based on baited video dataset regularly included large-scale measures of structural complexity, suggesting fish attraction to a single focus point by bait. Conversely, models based on the towed video data often incorporated small-scale measures of habitat complexity and were more likely to reflect true species-habitat relationships. The cost associated with use of the towed video systems for surveying low-relief seascapes was also relatively low providing additional support for considering this method for marine spatial ecological modelling. Full Text Available Estuarine environments are one of the most dynamic aquatic ecosystems and serve many important functions in coastal waters. Larval fish dynamics contribute significantly to understanding the ecology of fish populations as they can indicate the spawning-stock biomass and recruitment in adult fish stocks. Initial development stages of fishes are particularly vulnerable and are influenced by physical and biological processes. Hence the present study was aimed to characterize ichthyoplankton assemblages, to evaluate environmental influence in its structure. Ponnani backwater fish larvae assemblages displayed a clear seasonal pattern presenting higher abundances and diversities during warmer months. Throughout the year there is a wide fluctuation in salinity, temperature and primary productivity in these backwaters enabling it to be classified under stressful environment for larval forms of certain economically important marine fishes. A detailed analysis made to study the interaction of selected environmental parameters with ichthyofaunal diversity in Ponnani backwater provided a clear understanding on the influence of these variables on the distribution of marine fish larvae in the region. The results of the present analysis provided a model for the prediction of larval diversity from the prevailing environmental parameters. Vendel, A L; Bessa, F; Alves, V E N; Amorim, A L A; Patrício, J; Palma, A R T Our aim was to quantify microplastic ingestion by fish assemblages in two tropical Brazilian estuaries and to evaluate whether biological and ecological factors influence the ingestion of microplastics by fish species. Of 2233 fish from both estuaries (from 69 species) examined in this study, 9% of the individuals (24 species) had microplastics in their gut contents. Microplastic ingestion occurred irrespective of fish size and functional group. The diet of fish species was analyzed based on prey items identified in the fish's full stomach contents and five feeding guilds were defined. Microplastics were common throughout all feeding guilds. Low (average ingestion values 1.06±0.30 items/total fish) but widespread occurrence among estuaries also indicates proliferation of microplastic pollution. Our findings highlight the need to focus on assemblage level studies to understand the real magnitude of the problem and emphasize the urgency of mitigation measures directed at microplastic pollution in estuarine ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved. Ivasauskas, Tomas J.; Xiong, Wilson N.; Engman, Augustin C.; Fischer, Jesse R.; Kwak, Thomas J.; Rundle, Kirk R. Urban fisheries provide unique angling opportunities for people from traditionally underrepresented demographics. Lake Raleigh is a 38-ha impoundment located on the North Carolina State University campus in Raleigh. Like many urban fisheries, little is known about angler use and satisfaction or how angling catch rate is related to fish availability in Lake Raleigh. We characterized the recreational fishery and fish assemblage with concurrent creel and boat electrofishing surveys over the course of one year. In total, 245 anglers were interviewed on 68 survey days. On average, anglers spent 1.7 h fishing per trip and caught 0.385 fish h –1. A large proportion of anglers (43.9%) targeted multiple species, whereas 36.5% targeted largemouth bass (Micropterus salmoides), 10.0% targeted panfish (i.e., sunfishes [Lepomis spp.] and crappies [Pomoxis spp.]), and 9.6% targeted catfish (Ameiurus spp. and Ictalurus spp.). Most anglers (69.4%) were satisfied with their experience, and overall satisfaction was unrelated to catch rate. Pulsed-DC boat electrofishing was conducted on 25 dates, and 617 fish were sampled. Angler catch rate was unrelated to electrofishing catch rate, implying that anglers' catch rate was independent of fish density or availability. Our results demonstrate that even minimally managed urban fisheries can provide high angler satisfaction, with limited dedication of management resources. Relationships Among Catch, Angler Satisfaction, and Fish Assemblage Characteristics of an Urban Small Impoundment Fishery (PDF Download Available). Available from: https://www.researchgate.net/publication/316636550_Relationships_Among_Catch_Angler_Satisfaction_and_Fish_Assemblage_Characteristics_of_an_Urban_Small_Impoundment_Fishery [accessed Aug 11, 2017]. Lavergne, E; Zajonz, U; Krupp, F; Naseeb, F; Aideed, M S Estuarine and lagoonal surveys of Socotra Island and selected sites on the Hadhramout coast of Yemen were conducted with the objective of documenting and analysing fish diversity and assemblage structure. A total of 74 species in 35 families were recorded, among which 65 species in 32 families were from Socotra and 20 species in 17 families were from mainland Yemen. Twenty-one species represent new faunal records for Socotra. Including historic records re-examined in this study, the total fish species richness of estuaries and lagoons of Socotra Island reaches 76, which is relatively high compared to species inventories of well-researched coastal estuaries in southern Africa. Five species dominate the occurrence and abundance frequencies: Terapon jarbua, Hyporhamphus sindensis, Aphanius dispar, Ambassis gymnocephala and Chelon macrolepis. Rarefaction and extrapolation analyses suggest that the actual number of fish species inhabiting some of those estuaries might be higher than the one observed. Thus, additional sampling at specific sites should be conducted to record other less conspicuous species. Ordination and multivariate analyses identified four main distinct assemblage clusters. Two groups are geographically well structured and represent northern Socotra and mainland Yemen, respectively. The other two assemblage groups tend to be determined to a greater extent by the synchrony between physical (e.g. estuary opening periods) and biological (e.g. spawning and recruitment periods) variables than by geographical location. Finally, the single intertidal lagoon of Socotra represents by itself a specific fish assemblage. The high proportion of economically important fish species (38) recorded underscores the paramount importance of these coastal water bodies as nursery sites, and for sustaining vital provisioning ecosystem services. © 2016 The Fisheries Society of the British Isles. Zajicek, Petr; Radinger, Johannes; Wolter, Christian European large rivers are exposed to multiple human pressures and maintained as waterways for inland navigation. However, little is known on the dominance and interactions of multiple pressures in large rivers and in particular inland navigation has been ignored in multi-pressure analyzes so far. We determined the response of ten fish population metrics (FPM, related to densities of diagnostic guilds and biodiversity) to 11 prevailing pressures including navigation intensity at 76 sites in eight European large rivers. Thereby, we aimed to derive indicative FPM for the most influential pressures that can serve for fish-based assessments. Pressures' influences, impacts and interactions were determined for each FPM using bootstrapped regression tree models. Increased flow velocity, navigation intensity and the loss of floodplains had the highest influences on guild densities and biodiversity. Interactions between navigation intensity and loss of floodplains and between navigation intensity and increased flow velocity were most frequent, each affecting 80% of the FPM. Further, increased sedimentation, channelization, organic siltation, the presence of artificial embankments and the presence of barriers had strong influences on at least one FPM. Thereby, each FPM was influenced by up to five pressures. However, some diagnostic FPM could be derived: Species richness, Shannon and Simpson Indices, the Fish Region Index and lithophilic and psammophilic guilds specifically indicate rhithralisation of the potamal region of large rivers. Lithophilic, phytophilic and psammophilic guilds indicate disturbance of shoreline habitats through both (i) wave action induced by passing vessels and (ii) hydromorphological degradation of the river channel that comes along with inland navigation. In European large rivers, inland navigation constitutes a highly influential pressure that adds on top of the prevailing hydromorphological degradation. Therefore, river management has to consider Baldigo, Barry P.; George, Scott D.; Keller, Walter T The Upper Esopus Creek receives water diversions from a neighboring basin through the Shandaken Tunnel (the portal) from the Schoharie Reservoir. Although the portal is closed during floods, mean flows and turbidity of portal waters are generally greater than in Esopus Creek above their confluence. These conditions could potentially affect local fish assemblages, yet such effects have not been assessed in this highly regulated stream. We studied water quality, hydrology, temperature, and fish assemblages at 18 sites in the Upper Esopus Creek during 2009–2011 to characterize the effects of the portal input on resident-fish assemblages and to document the status of the fishery resource. In general, fish-community richness increased by 2–3 species at mainstem sites near the portal, and median density and biomass of fish communities at sites downstream of the portal were significantly lower than they were at sites upstream of the portal. Median densities of Salmo trutta (Brown Trout) and all trout species were significantly lower than at mainstem sites downstream from the portal—25.1 fish/0.1 ha and 148.9 fish/0.1 ha, respectively—than at mainstem sites upstream from the portal—68.8 fish/0.1 ha and 357.7 fish/0.1 ha, respectively—yet median biomass for Brown Trout and all trout did not differ between sites from both reaches. The median density of young-of-year Brown Trout at downstream sites (9.3 fish/0.1 ha) was significantly lower than at upstream sites (33.9 fish/0.1 ha). Waters from the portal appeared to adversely affect the density and biomass of young-of-year Brown Trout, but lower temperatures and increased flows also improved habitat quality for mature trout at downstream sites during summer. These findings, and those from companion studies, indicate that moderately turbid waters from the portal had few if any adverse impacts on trout populations and overall fish communities in the Upper Esopus Creek during this study. Full Text Available Tributary confluences play an important role in the dispersal of organisms, and consequently, in shaping regional scale diversity in stream networks. Despite their importance in dispersal processes, little is known about how ecological assemblages are organized in these habitats. We studied the scales of variability of stream fish assemblages over three seasons using a hierarchical sampling design, which incorporated three tributaries, three sites at the mouth of each tributary and using four sampling units at each site. We found strong scale dependent variability in species richness, composition and relative abundance. Most of the variation was accounted for by the interactive effect of season, between stream and between site effects, while habitat structure of the sampling units had a relatively minor role. Species richness showed a continuous decrease from the mainstem river in most cases, while species composition and relative abundance changed less consistently along the longitudinal profile. Consequently, we found that not only the junctions presented a strong filter on the species pool, but some species were filtered out if they passed this critical habitat bottleneck. Spatial position of the tributaries along the river also contributed to assemblage variability in the confluences. Overall, our results suggest high variability in fish assemblages across multiple scales at tributary confluences. Environmental management should take a more critical care on the filtering role of tributary confluences in species dispersal, for better understanding patterns and processes in the branches of dendritic stream networks. Full Text Available Biodiversity has reached a critical state. In this context, stakeholders need indicators that both provide a synthetic view of the state of biodiversity and can be used as communication tools. Using river fishes as model, we developed community indicators that aim at integrating various components of biodiversity including interactions between species and ultimately the processes influencing ecosystem functions. We developed indices at the species level based on (i the concept of specialization directly linked to the niche theory and (ii the concept of originality measuring the overall degree of differences between a species and all other species in the same clade. Five major types of originality indices, based on phylogeny, habitat-linked and diet-linked morphology, life history traits, and ecological niche were analyzed. In a second step, we tested the relationship between all biodiversity indices and land use as a proxy of human pressures. Fish communities showed no significant temporal trend for most of these indices, but both originality indices based on diet- and habitat- linked morphology showed a significant increase through time. From a spatial point of view, all indices clearly singled out Corsica Island as having higher average originality and specialization. Finally, we observed that the originality index based on niche traits might be used as an informative biodiversity indicator because we showed it is sensitive to different land use classes along a landscape artificialization gradient. Moreover, its response remained unchanged over two other land use classifications at the global scale and also at the regional scale. Lorion, Christopher M; Kennedy, Brian P Riparian forest buffers may play a critical role in moderating the impacts of deforestation on tropical stream ecosystems, but very few studies have examined the ecological effects of riparian buffers in the tropics. To test the hypothesis that riparian forest buffers can reduce the impacts of deforestation on tropical stream biota, we sampled fish assemblages in lowland headwater streams in southeastern Costa Rica representing three different treatments: (1) forested reference stream reaches, (2) stream reaches adjacent to pasture with a riparian forest buffer averaging at least 15 m in width on each bank, and (3) stream reaches adjacent to pasture without a riparian forest buffer. Land cover upstream from the study reaches was dominated by forest at all of the sites, allowing us to isolate the reach-scale effects of the three study treatments. Fish density was significantly higher in pasture reaches than in forest and forest buffer reaches, mostly due to an increase in herbivore-detritivores, but fish biomass did not differ among reach types. Fish species richness was also higher in pasture reaches than in forested reference reaches, while forest buffer reaches were intermediate. Overall, the taxonomic and trophic structure of fish assemblages in forest and forest buffer reaches was very similar, while assemblages in pasture reaches were quite distinct. These patterns were persistent across three sampling periods during our 15-month study. Differences in stream ecosystem conditions between pasture reaches and forested sites, including higher stream temperatures, reduced fruit and seed inputs, and a trend toward increased periphyton abundance, appeared to favor fish species normally found in larger streams and facilitate a native invasion process. Forest buffer reaches, in contrast, had stream temperatures and allochthonous inputs more similar to forested streams. Our results illustrate the importance of riparian areas to stream ecosystem integrity in the tropics Karen M Chong-Seng Full Text Available Accumulative disturbances can erode a coral reef's resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58% and high structural complexity to high macroalgae cover (up to 95% and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae. Kowalski, Kurt P.; Wiley, Michael J.; Wilcox, Douglas A. Fish and plant assemblages in the highly modified Crane Creek coastal wetland complex of Lake Erie were sampled to characterize their spatial and seasonal patterns and to examine the implications of the hydrologic connection of diked wetland units to Lake Erie. Fyke netting captured 52 species and an abundance of fish in the Lake Erie–connected wetlands, but fewer than half of those species and much lower numbers and total masses of fish were captured in diked wetland units. Although all wetland units were immediately adjacent to Lake Erie, there were also pronounced differences in water quality and wetland vegetation between the hydrologically isolated and lake-connected wetlands. Large seasonal variations in fish assemblage composition and biomass were observed in connected wetland units but not in disconnected units. Reestablishment of hydrologic connectivity in diked wetland units would allow coastal Lake Erie fish to use these vegetated habitats seasonally, although connectivity does appear to pose some risks, such as the expansion of invasive plants and localized reductions in water quality. Periodic isolation and drawdown of the diked units could still be used to mimic intermediate levels of disturbance and manage invasive wetland vegetation. Dembkowski, Daniel J.; Miranda, Leandro E. Disconnection between adjacent habitat patches is one of the most notable factors contributing to the decreased biotic integrity of global ecosystems. Connectivity is especially threatened in river–floodplain ecosystems in which channel modifications have disrupted the lateral links between the main river channel and floodplain lakes. In this study, we examined the interaction between the interconnectedness of floodplain lakes and main river channels and fish assemblage descriptors. Fish assemblages in two segments of an oxbow lake, one connected to and the other isolated from the Yazoo River, Mississippi, were estimated with daytime boat electrofishing during 2007–2010. The frequency of connection for the connected segment ranged from zero to seven individual events per year (mean, ∼2). The timing of most connection events reflected regional precipitation patterns. Greater species richness, diversity, and evenness were observed in the connected segment. Additionally, the connected segment had a greater abundance of piscivores and periodic life history strategists. All fishes collected solely in the connected segment were typically riverine in nature, whereas fishes collected only in the disconnected segment were more lacustrine adapted. These results suggest that periodic connection and the associated habitat heterogeneity that it provides are important for maintaining fish species richness and diversity in large-river floodplain lakes. We suggest that maintenance or restoration of connection be an integral part of fluvial ecosystem management plans. Fabrício Barreto Teresa Full Text Available We tested the hypothesis that streams in deforested areas shelter different fish communities to nearby forested areas, and that these disparities are due to environmental parameters that limit or benefit different species according to their functional traits. We compared the community composition of three south east Brazilian streams flanked by riparian forest with three nearby streams in deforested areas. The following functional traits were considered: diet, habitat use, water flow preference, size, and hypoxia tolerance. Differentiation between forested and deforested streams corresponded with the different contributions of three functional groups. Species reported in the literature to be hypoxia tolerant, and exhibiting a variable combination of the other traits prevailed in deforested streams, although we did not find substantial differences in oxygen levels between forested and deforested streams. In forested streams, benthic species associated with a high water flow and an insectivorous diet were dominant. Changes in streams induced by deforestation which are associated with habitat availability, food resources, and physicochemical conditions appear to restrict the occurrence of specialized species and instead benefit tolerant generalists. Benjamin L Richards Full Text Available Large-bodied reef fishes represent an economically and ecologically important segment of the coral reef fish assemblage. Many of these individuals supply the bulk of the reproductive output for their population and have a disproportionate effect on their environment (e.g. as apex predators or bioeroding herbivores. Large-bodied reef fishes also tend to be at greatest risk of overfishing, and their loss can result in a myriad of either cascading (direct or indirect trophic and other effects. While many studies have investigated habitat characteristics affecting populations of small-bodied reef fishes, few have explored the relationship between large-bodied species and their environment. Here, we describe the distribution of the large-bodied reef fishes in the Mariana Archipelago with an emphasis on the environmental factors associated with their distribution. Of the factors considered in this study, a negative association with human population density showed the highest relative influence on the distribution of large-bodied reef fishes; however, depth, water temperature, and distance to deep water also were important. These findings provide new information on the ecology of large-bodied reef fishes can inform discussions concerning essential fish habitat and ecosystem-based management for these species and highlight important knowledge gaps worthy of additional research. Hagan, S. M.; Able, K. W. The pelagic (i.e. fishes that spend most of their time swimming and feeding in the water column) fish assemblage was examined within a temperate estuary to determine the seasonal patterns of abundance, biomass, richness, and species composition. These measures were related to abiotic measures including temperature, salinity, water transparency, and depth. Pelagic fish (nGasterosteus aculeatus and age 1+ by M. menidia. Spring (April-early June) was overwhelmingly dominated by age 0+ C. harengus. Early summer (late June-early July) was relatively species rich and characterized by age 0+ of Brevoortia tyrannus, Pomatomus saltatrix, Alosa pseudoharengus, and age 1+ of A. mitchilli. Late summer (late July-August) remained relatively species rich and included mostly age 0+ of A. mitchilli, A. hepsetus, and M. menidia. Autumn (September-November) continued to have high catches of age 0+ of M. menidia and A. mitchilli. As expected for temperate estuaries, the best of the measured abiotic predictors of these groupings included temperature, salinity, and degree of change in temperature. However, timing of life history characteristics, such as location, and timing of reproduction and migration also influenced the seasonal occurrence of these pelagic species. The large abundance and biomass of a relatively few species, as observed in this study, are typical of estuaries, although this is one of the few studies that have focused solely on the pelagic component of estuarine fish assemblages. David A. Reynalte-Tataje Full Text Available Natural and induced disturbances greatly influence the temporal distribution of ichthyoplankton abundance. This study assesses and compares the temporal variability of fish larvae assemblages in controlled and free environments to determine the influence of environment variables on the main taxa in these systems. The study was conducted at the Chapecó (without dam impact and Ligeiro (with dam impact river mouths, which are located in the upper Uruguay River. Samples were made between October 2001 and March 2004 during three reproductive periods. The larvae assemblages were composed of small and medium-sized Characiformes and Siluriformes. The variation in the distribution of larvae was mainly temporal (>85%. When the three reproductive periods were compared, it was observed in the second period, characterized by a larger water flow and a lower temperature, that there was a reduction in abundance, a lower number of taxa, an absence of stages in post-flexion and a high dissimilarity in larvae assemblage structure. In general, the environmental variables of water flow and temperature most influenced the distribution of egg and larvae abundance. In the studied area, a smaller temporal variability was observed in the structure of larvae assemblages at the sampling sites in the Chapecó River mouth than in in the Ligeiro River mouth under the influence of dams. Size structure of a heavily fished benthic/demersal community by shrimp trawling in the Colombian Caribbean Sea Estructura de tamaños de una comunidad bentónica/demersal fuertemente impactada por la pesca de arrastre camaronero en el Mar Caribe de Colombia Full Text Available The benthic and demersal communities in the Colombian Caribbean Sea (CCS are heavily fished by the shrimp trawling fishery, which presents very high discard levels. Here, we conducted an analysis of the size structure of these benthic and demersal communities in the northern and southern zones of the CCS. Sampling was conducted onboard shrimp trawlers throughout an entire year. No significant differences were found in the size distributions of the two zones, among sites within southern ecoregions, or among the analyzed cruises. This homogeneity in size structure is remarkable since the zones analyzed possess very different species compositions and environmental conditions. The observed size structures were adequately described by non-linear distributions rather than the traditionally employed linear normalized biomass size spectra. It is hypothesized that the non-linearity is due to the effect of fishing and particularly, of discarding. This study emphasizes the need for a greater understanding of the impacts that trawl fishing has on community size structure and the applicability of this knowledge towards fishery resource management in ecosystems with high diversity.Las comunidades bentónico-demersales en el Mar Caribe de Colombia (MCC son fuertemente explotadas por la pesca de arrastre camaronero, presentando niveles de descarte muy altos. Se efectuó un análisis de la estructura de tamaños de estas comunidades bentónico-demersales en las zonas norte y sur del MCC. Se realizaron muéstreos a bordo de las embarcaciones de arrastre de camarón a lo largo de un año. No se encontraron diferencias significativas entre las distribuciones de tamaños de las diferentes zonas, ecorregiones de la zona sur y cruceros analizados. Esta homogeneidad en la estructura de tamaños es destacable ya que las areas analizadas difieren en composición de especies y condiciones medioambientales. Las estructuras de tamaño observadas, fueron descritas Robinson, Kelly F.; Jennings, Cecil A. The dominant fish species within impounded coastal wetlands in the southeastern US may be different from the species that dominate natural marshes. We tested the hypothesis that resident fish assemblages inhabiting impounded coastal wetlands in South Carolina would differ from resident assemblages in natural marshes of the southeastern United States. We used rarefied species richness, Shannon's H' diversity,J' evenness, Morisita's index of similarity, and the percent similarity index to compare resident fish assemblages from two impoundments to 12 open-marsh resident fish assemblages from previously published studies in North and South Carolina. We used rotenone to sample fish assemblages in impoundments. The assemblages in natural marsh habitat had been sampled with rotenone and seines. We classified comparisons yielding a similarity index ≥0.50 as moderately similar and those with an index ≥0.75 as very similar. Fifty-three percent of the among-impoundment comparisons (Morisita's index) were at least moderately similar, whereas 7% of impoundment—natural marsh comparisons were moderately similar. A difference in tidal influence was the only parameter in the best-fitting model describing the observed Morisita's indices. The index of similarity decreased by 63% when tidal influence differed between compared assemblages. Species richness and diversity were greater in impoundments than natural marshes, but evenness was similar between habitat types. Our results support the hypothesis that resident fish assemblages in impounded wetlands and natural marshes are different, and suggest that a degree of tidal influence is the most important factor behind the difference. Full Text Available Fish reproductions were studied in two river basins (Corumbataí and Jacaré-Pepira basins in the State of São Paulo, southeastern Brazil. In the Corumbataí basin, four sites were sampled: Cabeça River, Lapa Stream, Passa-Cinco River, and Corumbataí River; in the Jacaré-Pepira basin, three sites were sampled: Tamanduá Stream, Jacaré-Pepira River, and Água Branca Stream. A total of 12 bimonthly samples were made. Fish equipment included gill nets, purse seines, sieves, and traps. The main objective of this study was to characterize the fish assemblage regarding their reproductive biology and to compare these reproductive traits between both river basins. Most individuals with gonads in stage C (mature and in stage D (empty gonads were captured in the spring and summer. Multiple spawn and parental care were common strategies, which guaranteed offspring survivorship in unstable conditions. Miyazono, S.; Aycock, J.N.; Miranda, L.E.; Tietjen, T.E. We evaluated the influences of habitat connectivity and local environmental factors on the distribution and abundance patterns of fish functional groups in 17 floodplain lakes in the Yazoo River Basin, USA. The results of univariate and multivariate analyses showed that species-environmental relationships varied with the functional groups. Species richness and assemblage structure of periodic strategists showed strong and positive correlations with habitat connectivity. Densities of most equilibrium and opportunistic strategists decreased with habitat connectivity. Densities of certain equilibrium and opportunistic strategists increased with turbidity. Forested wetlands around the lakes were positively related to the densities of periodic and equilibrium strategists. These results suggest that decreases in habitat connectivity, forested wetland buffers and water quality resulting from environmental manipulations may cause local extinction of certain fish taxa and accelerate the dominance of tolerant fishes in floodplain lakes. ?? 2010 John Wiley & Sons A/S. Akin, S.; Winemiller, K. O.; Gelwick, F. P. Fish and macrocrustacean assemblage structure was analyzed along an estuarine gradient at Mad Island Marsh (MIM), Matagorda Bay, TX, during March 1998-August 1999. Eight estuarine-dependent fish species accounted for 94% of the individual fishes collected, and three species accounted for 96% of macrocrustacean abundance. Consistent with evidence from other Gulf of Mexico estuarine studies, species richness and abundance were highest during late spring and summer, and lowest during winter and early spring. Sites near the bay supported the most individuals and species. Associations between fish abundance and environmental variables were examined with canonical correspondence analysis. The dominant gradient was associated with water depth and distance from the bay. The secondary gradient reflected seasonal variation and was associated with temperature, salinity, dissolved oxygen, and vegetation cover. At the scales examined, estuarine biota responded to seasonal variation more than spatial variation. Estuarine-dependent species dominated the fauna and were common throughout the open waters of the shallow lake during winter-early spring when water temperature and salinity were low and dissolved oxygen high. During summer-early fall, sub-optimal environmental conditions (high temperature, low DO) in upper reaches accounted for strong spatial variation in assemblage composition. Small estuarine-resident fishes and the blue crab ( Callinectes sapidus) were common in warm, shallow, vegetated inland sites during summer-fall. Estuarine-dependent species were common at deeper, more saline locations near the bay during this period. During summer, freshwater species, such as gizzard shad ( Dorosoma cepedianum) and gars ( Lepisosteus spp.), were positively associated with water depth and proximity to the bay. The distribution and abundance of fishes in MIM appear to result from the combined effects of endogenous, seasonal patterns of reproduction and migration operating on large Chea, R.; Lek, S.; Grenouillet, G. Although the Mekong River is one of the world's 35 biodiversity hotspots, the large-scale patterns of fish diversity and assemblage structure remain poorly addressed. The present study aimed to investigate the spatial variability of water quality in the Lower Mekong Basin and the fish distribution patterns in the Lower Mekong River (LMR) and to identify their environmental determinants. Daily fish catch data at 38 sites distributed along the LMR were related to 15 physicochemical and 19 climatic variables. As a result, four different clusters were defined according to the similarity in assemblage composition and 80 indicator species were identified. While fish species richness was highest in the Mekong delta and lowest in the upper part of the LMR, the diversity index was highest in the middle part of the LMR and lowest in the delta. We found that fish assemblages changed along the environmental gradients and that the main drivers affecting the fish assemblage structure were the seasonal variation of temperature, precipitation, dissolved oxygen, pH, and total phosphorus. Specifically, upstream assemblages were characterized by cyprinids and Pangasius catfish, well suited to low temperature, high dissolved oxygen and high pH. Fish assemblages in the delta were dominated by perch-like fish and clupeids, more tolerant to high temperatures, and high levels of nutrients (nitrates and total phosphorus) and salinity. Overall, the patterns were consistent between seasons. Our study contributes to establishing the first holistic fish community study in the LMR. Overall of the LMR water quality, we found that the water in the mainstream was less polluted than its tributaries; eutrophication and salinity could be key factors affecting water quality in LMR. Moreover, the seasonal variation of water quality seemed to be less marked than spatial variation occurring along the longitudinal gradient of Mekong River. Significant degradations were mainly associated with human Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.; Schainost, Steve Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish-assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non-native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations. Full Text Available Incompletely known fish assemblages and species diversity are substantial obstacles in fish conservation, particularly when their aquatic habitats are under threat due to rapid human-induced changes. Fish assemblages and diversity in three tributaries of the upper Irrawaddy River in China (the Dulong, Daying and Ruili rivers were examined based on field collections and literature resources. The newly compiled fish assemblage recorded 85 species (in 8 orders, 20 families and 51 genera distributed in the upper Irrawaddy. The fish compositions in the Daying (67 species, 44 genera, 19 families, 7 orders and Ruili rivers (65 species, 44 genera, 19 families, 8 orders were more similar to each other and more speciose than that in the Dulong River (14 species, 10 genera, 4 families, 3 orders. Two indices of taxonomic diversity (the average taxonomic distinctness (Δ+, and the variation in taxonomic distinctness (Λ+ were used to discriminate four collections spanning a ten-year period. A decrease in taxonomic diversity and an increase in unevenness of the fish assemblages were found in both the Daying River and Ruili rivers, which indicated that the impacts were accumulated gradually during this decade, when dams and the spread of non-native species were major threats. Comparatively speaking, the Dulong River is still in a near-natural state, and thus the fish community has experienced less disturbance. In situ conservation (nature reserves and tributary protection and ex situ conservation (artificial propagation and release should be combined and managed to promote fish conservation in the future. Agudo-Adriani, Esteban A; Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts. Esteban A. Agudo-Adriani Full Text Available In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height, structural complexity (i.e., volume, density of branches, etc. and biological features of the colonies (i.e., live coral tissue, algae. We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts. In order to properly assess human impacts and appropriate restoration goals, baselines of pristine conditions on coral reefs are required. In Saudi Arabian waters of the central Red Sea, widespread and heavy fishing pressure has been ongoing for decades. To evaluate this influence, we surveyed the assemblage of offshore reef fishes in both this region as well as those of remote and largely unfished southern Sudan. At comparable latitudes, of similar oceanographic influence, and hosting the same array of species, the offshore reefs of southern Sudan provided an ideal location for comparison. We found that top predators (jacks, large snappers, groupers, and others) dominated the reef fish community biomass in Sudan’s deep south region, resulting in an inverted (top-heavy) biomass pyramid. In contrast, the Red Sea reefs of central Saudi Arabia exhibited the typical bottom-heavy pyramid and show evidence for trophic cascades in the form of mesopredator release. Biomass values from Sudan’s deep south are quite similar to those previously reported in the remote and uninhabited Northwest Hawaiian Islands, northern Line Islands, Pitcairn Islands, and other remote Pacific islands and atolls. The findings of this study suggest that heavy fishing pressure has significantly altered the fish community structure of Saudi Arabian Red Sea reefs. The results point towards the urgent need for enhanced regulation and enforcement of fishing practices in Saudi Arabia while simultaneously making a strong case for protection in the form of marine protected areas in the southern Sudanese Red Sea. Meador, Michael R.; Carlisle, Daren M. Management and conservation of aquatic systems require the ability to assess biological conditions and identify changes in biodiversity. Predictive models for fish assemblages were constructed to assess biological condition and changes in biodiversity for streams sampled in the eastern United States as part of the U.S. Geological Survey's National Water Quality Assessment Program. Separate predictive models were developed for northern and southern regions. Reference sites were designated using land cover and local professional judgment. Taxonomic completeness was quantified based on the ratio of the number of observed native fish species expected to occur to the number of expected native fish species. Models for both regions accurately predicted fish species composition at reference sites with relatively high precision and low bias. In general, species that occurred less frequently than expected (decreasers) tended to prefer riffle areas and larger substrates, such as gravel and cobble, whereas increaser species (occurring more frequently than expected) tended to prefer pools, backwater areas, and vegetated and sand substrates. In the north, the percentage of species identified as increasers and the percentage identified as decreasers were equal, whereas in the south nearly two-thirds of the species examined were identified as decreasers. Predictive models of fish species can provide a standardized indicator for consistent assessments of biological condition at varying spatial scales and critical information for an improved understanding of fish species that are potentially at risk of loss with changing water quality conditions. Siriwan, Suksri; Boonsatien, Boonsoong This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. Fish larvae were collected from 33 sampling stations on 8 occasions between August 2010 and October 2013. The study collected and identified 149 296 individuals, representing 32 families and 165 taxa. The species composition of larval fish was dominated by the Cyprinidae (47.27%), Cobitidae (7.88%), Siluridae (6.67%), Bagridae (6.06%) and Mastacembelidae (3.33%) families. The most-abundant larval species were the Striped flying barb Esomus metallicus (16.90%), the Siamese mud carp Henicorhynchus siamensis (8.48%) and the Sumatran river sprat Clupeichthys goniognathus (8.31%). The greatest abundance and species diversity of larvae were found when the river flow runs onto the floodplain. PCA and nMDS analysis revealed that the samples plot is associated with temporal distribution among years. The discharge was a major factor determining fish larvae assemblage and environmental variables in the Sukhothai floodplain. Four fish larval species were positively correlated with the samples for 2013. The result of the CCA ordination plot showed that only the discharge variable was strongly correlated with fish larvae abundance, especially two cyprinid Rasbora species. Milton P. Ávila Full Text Available ABSTRACT The development of effective monitoring tools depends on finding sensitive metrics that are capable of detecting the most important environmental impacts at a given region. We assessed if metrics derived from stream fish assemblages reflect physical habitat degradation and changes in land cover. We sampled the ichthyofauna and environmental characteristics of 16 stream sites of first and second order in the Upper Tocantins River basin. The streams were classified according to their environmental characteristics into reference (n = 5, intermediate (n = 4, and impacted (n = 7. A total of 4,079 individuals in five orders, 12 families, and 30 species were collected. Of the 20 metrics tested, eight were non-collinear and were tested for their performance in discriminating among groups of streams. Three metrics were sensitive to the gradient of degradation: Berger-Parker dominance index, percentage of characiform fish, and percentage of rheophilic individuals. Some commonly used metrics did not reflect the disturbances and many others were redundant with those that did. These results indicate that the metrics derived from fish assemblages may be informative for identifying the conservation status of streams, with the potential to be used in biomonitoring. Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas. Chen, Tsen-Chien; Ho, Cheng-Tze; Jan, Rong-Quen Recreational scuba diving is a popular activity of the coral reef tourism industry. In practice, local diving centers recommend interesting sites to help visiting divers make their plans. Fish are among the major attractions, but they need to be listed with care because the temporal occurrence of a fish species is difficult to predict. To address this issue, we propose methods to categorize each fish species based on its long-term occurrence and likelihood of being seen. We assume that there are K categories of occurrence of a fish assemblage and propose two methods [an arithmetic-mean method (AM) and a geometric-mean method (GM)] to define the range of species in each category. Experiments based on long term datasets collected at three underwater stations (each having 51-53 surveys and totals of 262-284 fish species) on coral reefs in southern Taiwan showed that when K = 4 (rare, occasional, frequent and common categories), 11-14 species were concurrently assigned to the common category by AM for data sets based on surveys 10, 15, 20, 25, 30, 35, 40, 45, or 51-53 in contrast to the 18-26 species assigned as common by GM. If a similarity index of 0.7 (compared to the total pool of fish species) was the minimum threshold for diver satisfaction, then 20-25 surveys provide sufficient data for listing the common species at a given dive spot. Common fish species, are the most temporally stable, and thus are more appropriate for attracting divers. These can be effectively differentiated by either AM or GM with at least 25 surveys. We suggest regular updating of each fish's category through periodic surveys to assure the accuracy of information at a particular dive spot. F. G. ARAÚJO Full Text Available Spatial distribution of fish assemblages in Lajes Reservoir, a 30 km² impoundment in Rio de Janeiro State (Lat. 22º42'-22º50'S; Long. 43º53'-44º05'W was assessed to detect patterns of available habitat use by the fish. A standardized monthly sampling program was carried out from January to December 1994 at three zones of the reservoir (upper, near tributary mouths; middle; and lower, near the dam. Fishes were caught by gillnets, (50 m long, 3 m height, with mesh ranging having from 25 to 45 mm between knots, submerged during 12 hours. A total of 5,089 fishes were collected comprising 15 species, 14 genera and 9 families. Loricariichthys spixii, Astyanax bimaculatus, Parauchenipterus striatulus, Astyanax fasciatus parahybae, Oligosarchus hepsetus, Rhamdia parahybae, Hypostomus affinis, and Geophagus brasiliensis were the most abundant species, each contributing above 1% of the total number. Loricariichthys spixii was the dominant species, contributing over 80% of total number and biomass. Fish abundance, number of species, and biomass were higher in the upper zone, but differences from this overall pattern were shown by some species. Loricariichthys spixii and Rhamdia parahybae were more abundant in the upper zone, while all other species showed no differences in their abundance among the zones. Seasonal environmental variables of temperature, pH, transparency, and water level did not show a clear association with fish occurrence. Most fish used the different zones of the reservoir with no clear sign of spatial separation. High dominance of L. spixii, reduced abundance of reolific species Leporinus copelandii and Cyphocharax gilberti, and presence of introduced species such as Cichla monoculus and Tilapia rendalli are indications of antropic effects in the fish community. José Roberto Mariano Full Text Available This study assessed differences in fish assemblages existing upstream and downstream two types of culverts, one on each of two different Neotropical streams. We analyzed the composition and structure of the ichthyofauna and tested for spatial patterns. Fish sampling was carried out monthly between November 2009 and October 2010 using different fishing gears. We collected 2,220 fish of 33 species; 901 in stretches of the Lopeí stream - circular culvert and 1,310 in stretches of the Pindorama stream - box culvert. Fish abundance was similar in upstream and downstream stretches of the circular culvert, whereas it was slightly higher in the upstream than downstream stretch for the box culvert. Characiformes predominated in the upstream stretch of both culverts. On the other hand, Siluriformes was abundant in the downstream stretch of the circular culvert, with similar abundance in the stretches of the box culvert. Species richness and diversity (Shannon-Weiner Index were higher in the downstream stretch of the circular culvert, but they were similar in both stretches of the box culvert. The most abundant species were Astyanax altiparanae, A. paranae, A. fasciatus, Ancistrus sp., and Hypostomus sp. The last two species were more abundant in the downstream stretch of the circular culvert, and similar in stretches of the box culvert. Our study indicated variations in the species abundance, richness, and diversity between upstream and downstream stretches in particular of the circular culvert in the Lopeí stream, suggesting that fish movements are restrained more intensively in this culvert, especially for Siluriformes. The drop in the circular culvert outlet probably created passage barriers especially for those fish that has no ability to jump, where downstream erosion could lead to culvert perching. Studies on appropriate road crossing design or installation are fundamental whereas improvements in these structures can restore the connectivity of Pedro Sartori Manoel Full Text Available The study of the diet of fish is an important tool to assess different levels of environmental degradation, since the availability of food in the environment is a key factor for the fish occurrence. The removal of riparian vegetation usually degrades environmental quality, as this vegetation has an important role in providing energy to the ecosystem. This study investigates the effects of the removal of riparian vegetation on the fish assemblage trophic network. The study was carried out in two stretches of a southeastern Brazilian stream, one in a forest fragment and another in a pasture, during the wet and dry seasons of 2014. We analyzed the items consumed by each fish species using the frequency of occurrence and area of each item, which were combined to calculate the alimentary index, which was used to determine the food niche overlap of the fish and the specialization index of the trophic network. Aquatic Hexapoda, vegetal debris and organic matter dominated the trophic network of the two stretches. We detected higher values of food niche overlap in the forested stretch and more complex trophic networks in the pasture stretch. We found few seasonal variations in the items consumed and calculated indices in both stretches studied. The presence of grass on the banks in the pasture stretch and the importation of food resources from the upstream area may have provided a higher diversity of resources and consequently showed a more complex trophic network when compared to the forested stretch. Fabíola Carla da Rocha Full Text Available Macrophytes are a major component of lentic and lotic aquatic ecosystems. As consequences of environmental degradation, species of cattail (genus Typha may become dominant along streams. The purpose of this study was to investigate the structure and feeding of fish assemblages in stream stretches under influence of Typha sp., also addressing the influences of temporal variation on composition, abundance, biomass, diversity, species richness, and feeding of fish. Six streams (labelled S1-S6 in the upper rio Turvo basin, southeast Brazil, with dense stands of Typha sp. in the instream and riparian habitat, were studied in six campaigns during three central months in both of the dry and wet periods, by using a standardized collection effort. Thirty-seven fish species were registered, totaling 4,228 individuals and 3.9 kg of biomass. Abundance, biomass, diversity, and species richness was higher in the wet period, but only the temporal variation in the species richness revealed to be statistically significant. Cluster analyses with composition and abundance showed little temporal similarity, but indicated two groups of streams (S1-S2-S5 and S3-S4-S6, that were corroborated along the axis 1 of the ordination analysis. Resident species was represented by six species, most of them considered tolerant and generalists. Chironomidae aquatic larvae and detritus were the most important items in the fish diet. These results suggest that the fish populations are opportunistic in exploring stream stretches occupied by cattail. Ben Lamine, Emna; Di Franco, Antonio; Romdhane, Mohamed Salah; Francour, Patrice Resource monitoring is a key issue in ecosystem management especially for marine protected areas (MPAs), where information on the composition and structure of fish assemblages is crucial to design a sound management plan. Data on fish assemblage are usually collected using Underwater Visual Censuses (UVC). However, fish assemblages monitoring in MPAs usually calls for considerable resources in terms of costs, time and technical/scientific skills. Financial resources and trained scientific divers may, however, not be available in certain geographical areas, that are thus understudied. Therefore, involving citizen volunteer divers in fish assemblage monitoring and adopting easy-to-use underwater visual census methods could be an effective way to collect crucial data. Citizen science can be used only if it can provide information that is consistent with that collected using standard scientific monitoring. Here, we aim to: 1) compare the consistency of results from a Standard scientific UVC (S-UVC) and an Easy-to-use UVC (E-UVC) method in assessing fish assemblage spatial variability, and 2) test the consistency of data collected by Scientific Divers (SD) and Scientifically-Trained Volunteer divers (STV), using E-UVC. We used, in two consecutive years, three Tunisian future Marine Protected Areas (MPAs) and adjacent areas as case studies. E-UVC and S-UVC data were consistent in highlighting the same spatial patterns for the three MPAs (between MPAs and, inside and outside each one). No significant difference was recorded between data collected by SD or STV. Our results suggest that E-UVC can provide information representing simplified proxies for describing fish assemblages and can therefore be a valuable tool for fish monitoring by citizen divers in understudied areas. This evidence could foster citizen science as an effective tool to raise environmental awareness and involve stakeholders in resource management. Marshall, S.; Elliott, M. Salinity, temperature, turbidity and dissolved oxygen were measured in conjunction with a series of fish samples taken by a 2 m beam trawl from 14 sites throughout the Humber estuary, U.K., over the period April 1992 to November 1994. Sediment type was not measured as the literature indicates that the area is homogeneous. The influences of environmental factors and the characteristics of the fish assemblage were analysed using a range of multivariate techniques, including two-way indicator species analysis, canonical correspondence analysis, principal components analysis and Spearman rank correlation. The analyses indicate that salinity is the dominant factor influencing the distribution of the species, with temperature also having a major influence. Of the species examined, whiting (Merlangius merlangus), sole (Solea solea), flounder (Pleuronectes flesus), sprat (Sprattus sprattus) and herring (Clupea harengus) showed a correlation in distribution to temperature, sole, plaice (Pleuronectes platessa), pogge (Agonus cataphractus) and stickleback (Gasterosteus aculeatus) to salinity, and whiting, flounder, pogge and stickleback to dissolved oxygen. Only cod (Gadus morhua) showed a correlation with tidal state, while whiting, pogge and stickleback were correlated to depth. Unlike in some other estuaries, turbidity did not influence the composition of the fish assemblage. Temperature and salinity fluctuations appear to influence different aspects of the community, with temperature proving to be the best predictor of total abundance, while salinity influenced the species richness and total biomass. The analyses demonstrate the most important variables with regard to environmental-biotic interactions, although they also indicate that the variables measured do not account for all of the observed variation in fish biomass and abundance. Full Text Available Human activities and the consequent extinctions of native species and invasions of non-native species have been changing the composition of species assemblages worldwide. These anthropogenic impacts alter not only the richness of assemblages but also the biological dissimilarity among them. However, much of the research effort to date has focused on changes in taxonomic dissimilarity (i.e. accounting for species composition whether assessments of functional dissimilarity (i.e. accounting for the diversity of biological traits are much more scarce, despite revealing important complimentary information by accounting for changes in the diversity of biological traits. Here, we assess the temporal (1950s against 2000s changes in both taxonomic and functional dissimilarities of freshwater fish assemblages across lakes from the Yunnan Plateau in China. The Jaccard index to quantify the changes in both taxonomic and functional dissimilarity. We then partitioned dissimilarity to extract its turnover component and measured the changes in the contribution of turnover to dissimilarity. We found that functional and taxonomic homogenization occurred simultaneously. However, patterns between these two processes differed for some lakes. Taxonomic and functional homogenizations were stronger when the historical level of taxonomic dissimilarity among assemblages was high. The impact of extinctions of native species and invasions of non-native species on homogenization was otherwise complex to disentangle with no significant effect of any of the studied environmental factors. In agreement with other studies, our study proved that change in taxonomic dissimilarity cannot be used to predict changes in functional dissimilarity and, as an indicator of ecosystem functioning, functional dissimilarity should be used together with taxonomic dissimilarity to attain a more holistic understanding of human impacts on natural ecosystems. Castellanos-Galindo, G. A.; Krumme, U. Intertidal fish assemblages are thought to respond to tidal and diel rhythms although the assumption that these patterns are stable over long time scales (>1 year) is largely untested. Testing the validity of this assumption is necessary to assess whether short-term temporal patterns, once established, can be extrapolated over time and give a better understanding of the temporal dynamics of fish assemblages in coastal habitats. Here, we compare the fish assemblage structure from two intertidal mangrove creeks in North Brazil (Bragança Peninsula, Caeté estuary) sampled with the same sampling methodology (block nets), effort (two lunar cycles) and design (accounting for the combination of tidal and diel cycle) in the rainy seasons of 1999 and 2012 to evaluate the persistence, stability and recurrence of short-term patterns in the fish community organization. The interaction of tidal and diel cycles (inundations at spring tide-night, spring tide-day, neap tide-night, neap tide-day), found to be stable after 13 years, resulted in recurrent and stable intertidal mangrove fish assemblage compositions. The intertidal mangrove creek fish assemblage consisted of a persistent number of dominant species (seven). However, there were notable changes in fish catch mass, abundance and species dominance between 1999 and 2012. The most severe drought in North Brazil in 30 years, linked to lower precipitation and river runoff in the rainy season of 2012, may have resulted in (1) lower abundance of small juveniles of several dominant species in this assemblage (especially Ariidae - Cathorops agassizii and Sciades herzbergii) and (2) increased dominance of large-sized specimens of the tetraodontid Colomesus psittacus. Our findings highlight: (1) the overriding importance and stability of the interactive pulse of the tidal and diel cycles in determining short-term temporal patterns in intertidal mangrove fish assemblages in neotropical macrotidal estuaries despite the occurrence of Cruz, Bruna B.; Miranda, Leandro E.; Cetra, Mauricio We hypothesised and tested a hierarchical organisation model where riparian landcover would influence bank composition and light availability, which in turn would influence instream environments and control fish assemblages. The study was conducted during the dry season in 11 headwater tributaries of the Sorocaba River in the upper Paraná River Basin, south-eastern Brazil. We focused on seven environmental factors each represented by one or multiple environmental variables and seven fish functional traits each represented by two or more classes. Multivariate direct gradient analyses suggested that riparian zone landcover can be considered a higher level causal factor in a network of relations that control instream characteristics and fish assemblages. Our results provide a framework for a hierarchical conceptual model that identifies singular and collective influences of variables from different scales on each other and ultimately on different aspects related to stream fish functional composition. This conceptual model is focused on the relationships between riparian landcover and instream variables as causal factors on the organisation of stream fish assemblages. Our results can also be viewed as a model for headwater stream management in that landcover can be manipulated to influence factors such as bank composition, substrates and water quality, whereas fish assemblage composition can be used as indicators to monitor the success of such efforts. Teichert, Nils; Lepage, Mario; Sagouis, Alban; Borja, Angel; Chust, Guillem; Ferreira, Maria Teresa; Pasquaud, Stéphanie; Schinegger, Rafaela; Segurado, Pedro; Argillier, Christine The impact of species loss on ecosystems functioning depends on the amount of trait similarity between species, i.e. functional redundancy, but it is also influenced by the order in which species are lost. Here we investigated redundancy and sensitivity patterns across fish assemblages in lakes, rivers and estuaries. Several scenarios of species extinction were simulated to determine whether the loss of vulnerable species (with high propensity of extinction when facing threats) causes a greater functional alteration than random extinction. Our results indicate that the functional redundancy tended to increase with species richness in lakes and rivers, but not in estuaries. We demonstrated that i) in the three systems, some combinations of functional traits are supported by non-redundant species, ii) rare species in rivers and estuaries support singular functions not shared by dominant species, iii) the loss of vulnerable species can induce greater functional alteration in rivers than in lakes and estuaries. Overall, the functional structure of fish assemblages in rivers is weakly buffered against species extinction because vulnerable species support singular functions. More specifically, a hotspot of functional sensitivity was highlighted in the Iberian Peninsula, which emphasizes the usefulness of quantitative criteria to determine conservation priorities. Miranda, Leandro E.; Andrews, Caroline S.; Kroger, Robert We explored the strength of connectedness among hierarchical system components associated with oxbow lakes in the alluvial valley of the Lower Mississippi River. Specifically, we examined the degree of canonical correlation between land use (agriculture and forests), lake morphometry (depth and size), nutrients (total nitrogen and total phosphorus), primary production (chlorophyll-a), and various fish assemblage descriptors. Watershed (p < 0.01) and riparian (p = 0.02) land use, and lake depth (p = 0.05) but not size (p = 0.28), were associated with nutrient concentrations. In turn, nutrients were associated with primary production (p < 0.01), and primary production was associated with sunfish (Centrarchidae) assemblages (p < 0.01) and fish biodiversity (p = 0.08), but not with those of other taxa and functional guilds. Multiple chemical and biological components of oxbow lake ecosystems are connected to landscape characteristics such as land use and lake depth. Therefore, a top-down hierarchical approach can be useful in developing management and conservation plans for oxbow lakes in a region impacted by widespread landscape changes due to agriculture. Martinez-Garcia, Elena; Sanchez-Jerez, Pablo; Aguado-Giménez, Felipe; Ávila, Pablo; Guerrero, Alejandro; Sánchez-Lizaso, Jose Luis; Fernandez-Gonzalez, Victoria; González, Nieves; Gairin, Joan Ignasi; Carballeira, Carlos; García-García, Benjamín; Carreras, Jordi Highlights: ► This study was carried out in ten fish farms along the Spanish coast. ► Fish farm caused a decline in abundance and family richness in polychaete assemblages. ► There are two main groups of polychaeta, sensitive families and tolerant families. ► The main influence is associated to percentage of silt and clays. ► Total free sulfides, silt and clays and 15 N, have influence on polychaete populations. -- Abstract: Marine fish farms could cause environmental disturbances on the sediment due to uneaten food and fish faeces that impact the marine benthos. Polychaete assemblages are considered good indicators of environmental perturbations. The present study aimed to establish groups of polychaetes as potential indicators of fish farm pollution. This study was carried out in ten fish farms along the Spanish coast. Changes in polychaete assemblage were analyzed with meta-analysis and multivariate techniques. Abundance, richness and diversity showed significant decreases under fish farm conditions. Distribution patterns of polychaetes responded to combinations of physicochemical variables. The main ones are sulfide concentration, silt and clays percentage, and stable nitrogen isotope ratio. The results showed that some families are tolerant, Capitellidae, Dorvilleidae, Glyceridae, Nereididae, Oweniidae and Spionidae; while others are sensitive to fish farm pollution, Magelonidae, Maldanidae, Nephtyidae, Onuphidae, Paralacydoniidae, Paraonide, Sabellidae and also Cirratulidae in spite of being reported as a tolerant family Full Text Available lakes), elements of the marine fish assemblage have persisted, especially the presence of facultative catadromous species. Freshwater fish diversity in coastal lakes and lagoons is a function of historical and present biogeography and salinity. From a... Gao, Qin-Feng; Cheung, Kwok-Leung; Cheung, Siu-Gin; Shin, Paul K S To study the correlation between nutrient enrichment derived from fish farming activities and changes in macrobenthic assemblages, a one-year field study was conducted in Kau Sai Bay marine fish culture zone of Hong Kong. Bimonthly sediment samples were collected at six stations: two at the fish cages, two near the boundary of the fish culture area, and two reference sites further away from the culture area. Sediment physico-chemical characteristics in terms of silt/clay fraction, moisture content, total organic carbon (TOC), total Kjeldahl nitrogen (TKN) and total phosphorus (TP) were analyzed. The macrobenthos (>0.5 mm) present in the sediment were sorted, identified and enumerated. On average, TOC, TKN and TP levels at the fish cage stations were 82.8%, 128.5% and 1315.7% higher than those at the reference stations, respectively. As a result, the N:P molar ratio was greatly reduced from 8.75 at the reference stations to 1.83 at the fish cage stations. Univariate and multivariate analyses revealed that diversity of macrofauna was significantly reduced and community structure differed at the fish cage stations relative to the reference sites. The intermediary stations near the fish culture area showed a transitional state of disturbance. Faunal diversity was negatively correlated with nutrient level, reflecting the adverse impacts of nutrient enrichment derived from fish farming activities on the benthic assemblages. Whilst in subtropical Asia-Pacific trash fish is the major feed for fish culture resulting in a higher nutrient loading and nutrient ratio accumulated in the sediment beneath the fish rafts, the effects of nutrient enrichment on macrobenthic assemblages are comparable to that in temperate waters owing to relatively high sediment metabolism rate and smaller fish culture scale in Hong Kong. Cavin, Lionel; Boudad, Larbi; Tong, Haiyan; Läng, Emilie; Tabouelle, Jérôme; Vullo, Romain The mid-Cretaceous vertebrate assemblage from south-eastern Morocco is one of the most diversified continental vertebrate assemblages of this time worldwide. The bony fish component (coelacanths, lungfishes and ray-finned fishes) is represented by relatively complete specimens and, mostly, by fragmentary elements scattered along 250 kilometres of outcrops. Here we revisit the bony fish assemblage by studying both isolated remains collected during several fieldtrips and more complete material kept in public collections. The assemblage comprises several lungfish taxa, with the first mention of the occurrence of Arganodus tiguidiensis, and possibly two mawsoniid coelacanths. A large bichir cf. Bawitius, is recorded and corresponds to cranial elements initially referred to 'Stromerichthys' from coeval deposits in Egypt. The ginglymodians were diversified with a large 'Lepidotes' plus two obaichthyids and a gar. We confirm here that this gar belongs to a genus distinctive from Recent gars, contrary to what was suggested recently. Teleosteans comprise a poorly known ichthyodectiform, a notopterid, a probable osteoglossomorph and a large tselfatiiform, whose cranial anatomy is detailed. The body size and trophic level for each taxon are estimated on the basis of comparison with extant closely related taxa. We plotted the average body size versus average trophic level for the Kem Kem assemblage, together with extant marine and freshwater assemblages. The Kem Kem assemblage is characterized by taxa of proportionally large body size, and by a higher average trophic level than the trophic level of the extant compared freshwater ecosystems, but lower than for the extant marine ecosystems. These results should be regarded with caution because they rest on a reconstructed assemblage known mostly by fragmentary remains. They reinforce, however, the ecological oddities already noticed for this mid-Cretaceous vertebrate ecosystem in North Africa. Full Text Available We examined mercury concentrations in three fish assemblages to estimate biomagnification rates in the Iténez main river, affected by anthropogenic activities, and two unperturbed rivers from the Iténez basin, Bolivian Amazon. Rivers presented low to moderate water mercury concentrations (from 1.25 ng L(-1 to 2.96 ng L(-1 and natural differences in terms of sediment load. Mercury biomagnification rates were confronted to trophic structure depicted by carbon and nitrogen stable isotopes composition (δ(15N; δ(13C of primary trophic sources, invertebrates and fishes. Results showed a slight fish contamination in the Iténez River compared to the unperturbed rivers, with higher mercury concentrations in piscivore species (0.15 µg g(-1 vs. 0.11 µg g(-1 in the unperturbed rivers and a higher biomagnification rate. Trophic structure analysis showed that the higher biomagnification rate in the Iténez River could not be attributed to a longer food chain. Nevertheless, it revealed for the Iténez River a higher contribution of periphyton to the diet of the primary consumers fish species; and more negative δ(13C values for primary trophic sources, invertebrates and fishes that could indicate a higher contribution of methanotrophic bacteria. These two factors may enhance methylation and methyl mercury transfer in the food web and thus, alternatively or complementarily to the impact of the anthropogenic activities, may explain mercury differences observed in fishes from the Iténez River in comparison to the two other rivers. Pires, Mathias M.; Guimarães, Paulo Roberto; Hoey, Andrew S.; Hay, Mark E. The establishment of no-take marine protected areas (MPAs) on coral reefs is a common management strategy for conserving the diversity, abundance, and biomass of reef organisms. Generally, well-managed and enforced MPAs can increase or maintain the diversity and function of the enclosed coral reef, with some of the benefits extending to adjacent non-protected reefs. A fundamental question in coral reef conservation is whether these benefits arise within small MPAs (fish assemblages, composition of fish feeding groups, benthic cover, and key ecosystem processes (grazing, macroalgal browsing, and coral replenishment) in three small (0.5–0.8 km2) no-take MPAs and adjacent areas where fisheries are allowed (non-MPAs) on coral reefs in Fiji. The MPAs exhibited greater species richness, density, and biomass of fishes than non-MPAs. Furthermore, MPAs contained a greater abundance and biomass of grazing herbivores and piscivores as well as a greater abundance of cleaners than fished areas. We also found differences in fish associations when foraging, with feeding groups being generally more diverse and having greater biomass within MPAs than adjacent non-MPAs. Grazing by parrotfishes was 3–6 times greater, and macroalgal browsing was 3–5 times greater in MPAs than in non-MPAs. On average, MPAs had 260–280% as much coral cover and only 5–25% as much macroalgal cover as their paired non-MPA sites. Finally, two of the three MPAs had three-fold more coral recruits than adjacent non-MPAs. The results of this study indicate that small MPAs benefit not only populations of reef fishes, but also enhance ecosystem processes that are critical to reef resilience within the MPAs. PMID:28122006 González-Sansón, Gaspar; Aguilar, Consuelo; Hernández, Ivet; Cabrera, Yureidy; Suarez-Montes, Noelis; Bretos, Fernando; Guggenheim, David The main goal of the study was to obtain field data to build a baseline of fish assemblage composition that can be used comparatively for future analyses of the impact of human actions in the region. A basic network of 68 sampling stations was defined for the entire region (4,050 km2). Fish assemblage species and size composition was estimated using visual census methods at three different spatial scales: a) entire region, b) inside the main reef area and c) along a human impact coastal gradient. Multivariate numerical analyses revealed habitat type as the main factor inducing spatial variability of fish community composition, while the level of human impact appears to play the main role in fish assemblage composition changes along the coast. A trend of decreasing fish size toward the east supports the theory of more severe human impact due to overfishing and higher urban pollution in that direction. This is the first detailed study along the northwest coast of Cuba that focuses on fish community structure and the natural and human-induced variations at different spatial scales for the entire NW shelf. This research also provides input for a more comprehensive understanding of coastal marine fish communities' status in the Gulf of Mexico basin. Mustapha, Moshood K Agricultural and fisheries activities around the watershed of an African tropical reservoir (Oyun reservoir, Offa, Nigeria) were found to contribute significantly to water quality deterioration of the dam axis of the reservoir, leading to eutrophication of that part of the reservoir. This is evident from the high amount of nitrate (6.4 mg/l), phosphate (2.2 mg/l) and sulphate (16.9 mg/l) in the water body which was higher than most other reservoirs in Nigeria. These nutrients originate in fertilizer run-offs from nearby farmlands and were found in higher concentrations in the rainy season which is usually the peak of agricultural activities in the locality. The eutrophication was more pronounced on the dam axis because it is the point of greatest human contact where pressure and run-off of sediments were high. The eutrophication altered the food web cycle which consequently affected the fish species composition and abundance with the dominance of cichlids (planktivorous group) and decline of some species in the fish population. Best management practices (BMP) to control and reduce the eutrophication and improve water quality and fish assemblages should be adopted and adapted to suit the situation in the reservoir. Full Text Available Tidal creeks are strongly influenced by tides and are therefore exposed to large differences in salinity and depth daily. Here we compare fish assemblages in tidal creeks between day and night in two tidal creeks in southern Brazil. Monthly day and night, simultaneous collections were carried out in both creeks using fyke nets. Clupeiformes tended to be caught more during the day. Cathorops spixii, Genidens genidens and Rypticus randalli tended to be caught at night. Sciaenidae also tended to be caught more during the night. In general, pelagic species were diurnal, while deep water species were nocturnal. These trends are probably due to a variety of causes, such as phylogeny, predation and net avoidance. Moreno-Valcárcel, Raquel; Oliva-Paterna, Francisco J.; Arribas, Carmen; Fernández-Delgado, Carlos The Guadalquivir estuary is the largest estuarine area on the southern Atlantic coast of Europe; its anthropogenic tidally-restricted marshes are partly within the boundary of the Doñana National Park, southern Spain. Our two-year study describes the spatial and temporal patterns of the fish assemblages in the Doñana marshlands in terms of species richness, abundance and biomass. The main families were Mugilidae and Cyprinidae, which accounted for 40.9% of the total species richness. Unlike the fish assemblages found in other European estuaries, Doñana was dominated in both biomass and abundance by freshwater species, mainly invasive exotic species. The spatial analysis of the assemblage showed four significant fish groups corresponding to different habitats established a priori and related to the salinity gradient. Assemblages did not show a seasonal pattern and the temporal fish groups observed were mainly related to the hydrological cycle and the extreme drought that occurred during the study period. Kutsokon, Y.; Kvach, Yuriy Roč. 9, č. 1 (2015), s. 223-228 ISSN 1996-4536 Institutional support: RVO:68081766 Keywords : Tyligul River * fish * assemblage * Northern Black Sea * museum collections Subject RIV: EH - Ecology, Behaviour http://bioweb.lnu.edu.ua/studia/pdf/201591/2015_9_1_382.pdf Salvador J. Jorgensen Full Text Available Seamounts have generally been identified as locations that can promote elevated productivity, biomass and predator biodiversity. These properties attract seamount-associated fisheries where elevated harvests can be obtained relative to surrounding areas. There exists large variation in the geological and oceanographic environment among the thousands of locations that fall within the broad definition of seamount. Global seamount surveys have revealed that not all seamounts are hotspots of biodiversity, and there remains a strong need to understand the mechanisms that underlie variation in species richness observed. We examined the process of fish species assembly at El Bajo Espiritu Santo (EBES seamount in the Gulf of California over a five-year study period. To effectively quantify the relative abundance of fast-moving and schooling fishes in a ‘blue water’ habitat, we developed a simplified underwater visual census (UVC methodology and analysis framework suitable for this setting and applicable to future studies in similar environments. We found correlations between seasonally changing community structure and variability in oceanographic conditions. Individual species responses to thermal habitat at EBES revealed three distinct assemblages, a ‘fall assemblage’ tracking warmer overall temperature, a ‘spring assemblage’ correlated with cooler temperature, and a ‘year-round assemblage’ with no significant response to temperature. Species richness was greatest in spring, when cool and warm water masses stratified the water column and a greater number of species from all three assemblages co-occurred. We discuss our findings in the context of potential mechanisms that could account for predator biodiversity at shallow seamounts. Full Text Available Tulisan ini menyajikan hasil kajian potensi produksi dan upaya penangkapan optimal serta menjelaskan perkembangan perikanan demersal di Laut Arafura, termasuk pula estimasi dampak peningkatan upaya penangkapan terhadap produktivitas kapal dan hasil tangkapan ikan demersal. Kajian menggunakan data statistik produksi perikanan yang dikoreksi dengan menambahkan estimasi hasil tangkapan yang tidak tercatat dan data jumlah kapal penangkap dengan memperhitungkan pula estimasi jumlah kapal yang beroperasi secara ilegal. Berdasarkan hasil analisis, potensi produksi ikan demersal yang dapat dihasilkan secara lestari dari pemanfaatan stok ikan demersal di Laut Arafura adalah 539 ribu ton/tahun dengan upaya penangkapan sekitar 903 unit kapal pukat ikan 180 GT. Walaupun upaya penangkapan dari kapal yang memiliki surat izin penangkapan ikan di Laut Arafura tahun 2011 lebih rendah dibandingkan upaya penangkapan optimal untuk menghasilkan MSY, stok ikan demersal tersebut telah dimanfaatkan melebihi tingkat optimumnya akibat tingginya intensitas operasi kapal perikanan tanpa izin. Estimasi kerugian hasil tangkapan akibat kegiatan penangkapan ikan ilegal juga disajikan disini. This paper presents result of the assessment of potential production and optimal fishing effort, and briefly describes the past development of the demersal fishery in the Arafura Sea, including the estimated impact of increased fishing effort on the productivity of vessels and demersal fish catches. The assessment used corrected fisheries statistic data taking into account unreported catches and corrected fishing vessel data taking into account vessels operated illegally. Based on the analysis, the production potential of demersal fish that can be produced in a sustainable manner of demersal fish stocks in the Arafura Sea is 539 thousand tons/year to attempt the arrest of about 903 units of fishing trawlers 180 GT. Although fishing effort from vessels granted license in Olivar, M. Pilar; Gonzá lez-Gordillo, J. Ignacio; Salat, Jordi; Chust, Guillem; Có zar, André s; Herná ndez-Leó n, Santiago; Ferná ndez de Puelles, M. Luz; Irigoien, Xabier Surface waters are an attractive foraging ground for small fish in the open ocean. This study aims to determine the importance of vertically migrating species in the neuston of oceanic waters across the Atlantic, Indian and Pacific Oceans and to ascertain the influence of environmental variables on their distribution patterns. Neustonic fish assemblages were primarily controlled by light. They were dominated by late-larvae and juveniles of Exocoetidae, Hemiramphidae and Scomberesocidae during the day. At night, the vertical migration of mesopelagic species changed the dominance pattern in favour of Myctophidae and Scomberesocidae. The neustonic families' distribution was primarily related to sea surface temperatures, whereas environmental variables at deeper layers were related to mesopelagic migrating families. Canonical correspondence analysis showed a low but statistically significant contribution of several environmental variables to myctophid species composition (10%), with minimum oxygen concentrations ranking first in variance explanation followed by maximum fluorescence, sea surface temperature and 400-m temperature. Spatial autocorrelation also explained 17% of the variance, indicating the influence of other factors such as historical, demographic and dispersal constraints. The low number of myctophid species in the North Pacific Equatorial Countercurrent appears to be related to the low oxygen concentrations observed in this province. Olivar, M. Pilar Surface waters are an attractive foraging ground for small fish in the open ocean. This study aims to determine the importance of vertically migrating species in the neuston of oceanic waters across the Atlantic, Indian and Pacific Oceans and to ascertain the influence of environmental variables on their distribution patterns. Neustonic fish assemblages were primarily controlled by light. They were dominated by late-larvae and juveniles of Exocoetidae, Hemiramphidae and Scomberesocidae during the day. At night, the vertical migration of mesopelagic species changed the dominance pattern in favour of Myctophidae and Scomberesocidae. The neustonic families\\' distribution was primarily related to sea surface temperatures, whereas environmental variables at deeper layers were related to mesopelagic migrating families. Canonical correspondence analysis showed a low but statistically significant contribution of several environmental variables to myctophid species composition (10%), with minimum oxygen concentrations ranking first in variance explanation followed by maximum fluorescence, sea surface temperature and 400-m temperature. Spatial autocorrelation also explained 17% of the variance, indicating the influence of other factors such as historical, demographic and dispersal constraints. The low number of myctophid species in the North Pacific Equatorial Countercurrent appears to be related to the low oxygen concentrations observed in this province. O'Neill, F G; Summerbell, K The mobilisation of sediment by towed demersal fishing gears has been related to the release of nutrients, benthic infaunal mortality and the resuspension of phytoplankton cysts and copepod eggs. Hence, to understand the broader environmental and ecological implications of demersal fishing, it is important to be able to estimate accurately the amount of sediment put into the water column by towed gears. Experimental trials were carried out in the Moray Firth, Scotland, to measure the quantity of sediment remobilised by trawl gear components. It is demonstrated, for a given sediment type, that there is a relationship between the hydrodynamic drag of the gear element and the mass of sediment entrained behind it. A better understanding of this relationship and the hydrodynamic processes involved will lead to the development of accurate predictive models and aid the design of fishing gears of reduced impact. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved. Stewart, Jana S.; Lizhu Wang,; Infante, Dana M.; Lyons, John D.; Arthur Cooper, Regional assessment of cumulative impacts of dams on riverine fish assemblages provides resource managers essential information for dam operation, potential dam removal, river health assessment and overall ecosystem management. Such an assessment is challenging because characteristics of fish assemblages are not only affected by dams, but also influenced by natural variation and human-induced modification (in addition to dams) in thermal and flow regimes, physicochemical habitats and biological assemblages. This study evaluated the impacts of dams on river fish assemblages in the non-impoundment sections of rivers in the states of Michigan and Wisconsin using multiple fish assemblage indicators and multiple approaches to distinguish the influences of dams from those of other natural and human-induced factors. We found that environmental factors that influence fish assemblages in addition to dams should be incorporated when evaluating regional effects of dams on fish assemblages. Without considering such co-influential factors, the evaluation is inadequate and potentially misleading. The role of dams alone in determining fish assemblages at a regional spatial scale is relatively small (explained less than 20% of variance) compared with the other environmental factors, such as river size, flow and thermal regimes and land uses jointly. However, our results do demonstrate that downstream and upstream dams can substantially modify fish assemblages in the non-impoundment sections of rivers. After excluding river size and land-use influences, our results clearly demonstrate that dams have significant impacts on fish biotic-integrity and habitat-and-social-preference indicators. The influences of the upstream dams, downstream dams, distance to dams, and dam density differ among the fish indicators, which have different implications for maintaining river biotic integrity, protecting biodiversity and managing fisheries. Full Text Available Reservoirs can have both positive and negative effects on differing fish species depending on the species concerned and reservoir morphology, flow regime, and basin location. We assessed the influence of limnological zones on the ichthyofauna of three large Neotropical reservoirs in two different river basins. We sampled fish through use of gill nets set at 40 systematically selected sites on each reservoir. We used satellite images, algae, and suspended solids concentrations to classify those sites as lacustrine or riverine. We observed significant differences in assemblage composition between riverine and lacustrine zones of each reservoir. We either tested if the same region (lacustrine or riverine showed the same patterns in different reservoirs. In São Simão, the riverine zone produced greater abundances of native species, long-distance migratory species, diversity, and richness, whereas the lacustrine zone supported greater total and non-native species abundances. Conversely, in Três Marias, the riverine zone supported greater total and non-native species abundances, whereas the others traits evaluated did not differ significantly between zones. Only lacustrine sites occurred in Volta Grande Reservoir. The same zones in the three reservoirs usually had significantly different patterns in the traits evaluated. The differences in spatial patterns observed between reservoirs could be explained partly by the differing morphologies (complex versus linear, the differential influence of tributaries of each reservoir and basin positions (presence or absence of upstream dams of the reservoirs. Full Text Available Patterns in the mesoscale distribution of larval fish in the coastal waters of central Greece, an area of high topographic and bathymetric complexity, were analysed using samples collected during two ichthyoplankton surveys in July 1998 and June 1999. Salinities were lower in the eastern (Aegean part of the study area due to the influence of waters originating from the Black Sea. In this region, larvae of many epipelagic and benthopelagic (typically summer spawning species were less abundant in June 1999, when waters were significantly cooler, compared to July 1998. Multivariate analyses identified ‘neritic’ and ‘pelagic’ groups of stations dominated by larvae of epipelagic/bethopelagic (typically shelf dwelling and mesopelagic species. In the west (Ionian Sea, a prominent third group of stations located in the deep and highly enclosed Korinthiakos Gulf was also defined with very high abundances of mesopelagic fish larvae. However, the genera Cyclothone and Vinciguerria that dominated the neighbouring offshore assemblage of the Ionian Sea were absent from this gulf. In the study area, Korinthiakós Gulf ( > 900 m and North Evoikos ( > 400 m Gulf comprise unique ‘fjord-like’ ecosystems in the Mediterranean with increased productivity and significantly cooler deep waters compared to adjacent open sea basins. Heenan, Adel; Williams, Ivor D; Acoba, Tomoko; DesRochers, Annette; Kosaki, Randall K; Kanemura, Troy; Nadon, Marc O; Brainard, Russell E Throughout the tropics, coral reef ecosystems, which are critically important to people, have been greatly altered by humans. Differentiating human impacts from natural drivers of ecosystem state is essential to effective management. Here we present a dataset from a large-scale monitoring program that surveys coral reef fish assemblages and habitats encompassing the bulk of the US-affiliated tropical Pacific, and spanning wide gradients in both natural drivers and human impact. Currently, this includes >5,500 surveys from 39 islands and atolls in Hawaii (including the main and Northwestern Hawaiian Islands) and affiliated geo-political regions of American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and the Pacific Remote Islands Areas. The dataset spans 2010-2017, during which time, each region was visited at least every three years, and ~500-1,000 surveys performed annually. This standardised dataset is a powerful resource that can be used to understand how human, environmental and oceanographic conditions influence coral reef fish community structure and function, providing a basis for research to support effective management outcomes. Pessanha, André Luiz Machado; Araújo, Francisco Gerson Fish assemblages from two beaches, one in the inner and the other in the outer Sepetiba Bay (latitude: 22°54'-23°04'S; longitude: 43°34'-44°10'W), Southeast Brazil, were sampled by beach seine net, simultaneously, on both seasonal and diel scales, between August 1998 and June 1999. Sites were selected to encompass different environmental conditions which reflect the two bay zones, thus providing a comprehensive assessment of the factors influencing surf zone fish assemblages, and their spatial, seasonal and diel variations. A total of 55 fish species was recorded, mostly young-of-the-year. Anchoa tricolor, Micropogonias furnieri, Gerres aprion, Diapterus rhombeus, Harengula clupeola, Atherinella brasiliensis and Mugil liza were numerically dominant and contributed to 95.2% of the total fish catches. Strong differences in fish assemblages were observed between the two areas, with higher number of species in the outer bay. Increases in fish numbers occurred in winter, while the highest biomass occurred in winter and summer. Transparency, followed by salinity, was responsible for most of the spatial variability and played an important role in structuring fish assemblages. Overall, diel patterns did not reveal any significant trends; however, if we consider each season separately, an increase in fish numbers during the day with peak at sunset was observed in winter, and a higher biomass occurred at night in winter and summer. Species preferences for various combinations of environmental variables are responsible for shifts in the structure and overall abundance of assemblages and dictated some patterns. The sciaenid M. furnieri, the second most abundant species, occurred only in the inner zone, being more abundant in winter. The species of Engraulidae were more abundant in the outer zone in winter/spring during the day. The gerreids G. aprion and D. rhombeus occurred mainly in summer. Overall, temporal fluctuations act more at a specific level than at a structural Abesamis, Rene A.; Langlois, Tim; Birt, Matthew; Thillainath, Emma; Bucol, Abner A.; Arceo, Hazel O.; Russ, Garry R. Baseline ecological studies of mesophotic coral ecosystems are lacking in the equatorial Indo-West Pacific region where coral reefs are highly threatened by anthropogenic and climate-induced disturbances. Here, we used baited remote underwater video to describe benthic habitat and fish assemblage structure from 10 to 80 m depth at Apo Island, a well-managed marine protected area in the Philippines. We conducted surveys 2 yr after two storms (in 2011 and 2012) caused severe damage to shallow coral communities within the no-take marine reserve (NTMR) of Apo Island, which led to declines in fish populations that had built up over three decades. We found that hard coral cover was restricted to the storm-impacted NTMR and a nearby fished area not impacted by storms. Benthic cover at mesophotic depths (> 30 m) was dominated by sand/rubble and rock (dead coral) with low cover of soft corals, sponges and macroalgae. Storm damage appeared to have reached the deepest limit of the fringing reef (40 m) and reduced variability in benthic structure within the NTMR. Species richness and/or abundance of most trophic groups of fish declined with increasing depth regardless of storm damage. There were differences in taxonomic and trophic structure and degree of targeting by fisheries between shallow and mesophotic fish assemblages. Threatened shark species and a fish species previously unreported in the Philippines were recorded at mesophotic depths. Our findings provide a first glimpse of the benthic and fish assemblage structure of Philippine coral reef ecosystems across a wide depth gradient. This work also underscores how a combination of limited coral reef development at mesophotic depths close to shallow reefs and severe habitat loss caused by storms would result in minimal depth refuge for reef fish populations. Teichert, Nils; Lepage, Mario; Lobry, Jérémy Assessing ecological health of aquatic ecosystems is crucial in the current context of biodiversity loss to guide and prioritize management actions. Although several fish-based indices were developed to assess the ecological status of estuarine ecosystems, they do not provide guidance on the causal responses of communities to disturbances. The functional trait-based approach provides an understanding of how human disturbance affects the composition of biological and ecological traits in assemblages, as well as their consequences for ecosystem functioning. Here, we evaluate the responses of fish assemblages to human disturbance in 30 French estuaries using several taxonomic and functional indices (e.g. diversity, evenness or redundancy). We tested whether these indices can provide additional information on the human impacts and health of assemblages that are not reflected by the ecological indicator (fish-based index ELFI). Results indicated that high values of local human disturbances were associated to a decrease in fish abundance, decrease in species richness and reduced functional redundancy, whereas taxonomic and functional evenness increased. In contrast, the functional richness remained stable suggesting that the functional traits of species removed by stressors were maintained by more tolerant species. Indeed, we found that the local disturbances mainly resulted in a decrease in the proportions of small benthic species feeding on macro-invertebrates, which were dominant in the studied estuaries. Some functional alterations were detected by the fish-based index, but the decline of functional redundancy was not reflected, highlighting a serious concern for management. Indeed, the abrupt collapse of functional redundancy in response to local disturbances can decrease the ability of assemblages to maintain certain species traits in the face of future environmental disturbance, including climate change. From a management perspective, the application of such Fock, H.; Uiblein, F.; Köster, Fritz , respectively, to 583.98 ind. m(-1) h(-1) in 1998. Gear effects and an effect of gear over time accounted for 47.1% and 20% of species variability. Further significant factors were time of day and habitat, while season was not significant. A total of 43 species was collected. Including supplementary species...... information, a grand total of 46 species was found associated with the Great Meteor Seamount. Diversity was higher in 1967 and 1970 (Shannon's diversity: H'=2.5 and 1.6) than in 1998 (H'=0.9). Species-environment relationships are discussed in terms of a sound-scattering layer-interception hypothesis, i... Full Text Available Structural patterns of a sublittoral community were analyzed through a two-year series of samples in the Southwestern Gulf of Mexico. The groups involved in the study comprise fishes, molluscs, echinoderms and crustaceans. The time-space progressions of Second 0rder diversity values range between N2=5.3 and N2=9.8 at depths of 40 and 20 m respectively, through the first year of samples. In the second year the highest value (N2=22.2 was found at 30 m. The community ordination data through cluster and principal components analysis show five assemblages: benthic, benthic-demersal, demersal, mid water column, and temporary. There is a striking difference in trophic web structure between the dry season and rainy season. Fish community resource partitioning shows that the components are organized in three guilds: ichthyophagous, carcinophagous and omnivorous. However, a partial overlap of niches was commonly observed, and juvenile stages showed a narrower trophic spectrum than adults. Rev. Biol. Trop. 55 (2: 509-536. Epub 2007 June, 29.Se analizaron los patrones estructurales de la comunidad sublitoral a través de dos años de muestreo. Los grupos involucrados en el estudio fueron: peces, moluscos, equinodermos y crustáceos. Las progresiones espacio-temporales de la diversidad de segundo orden para el primer año se encuentran entre los intervalos de N2=5.3 y N2=9.8 en las profundidades de 40 y 20 m respectivamente. En el segundo periodo el valor más alto (N2=22.2 fue registrado a 30 m. La ordenación de la comunidad a través del análisis de agrupamientos y de Componentes Principales, muestran 5 ensamblajes: béntico, béntico-demersal, demersal, a media columna de agua y temporal. Hay una fuerte diferencia en la estructura de la red trófica entre las estaciones de secas y lluvias. La repartición de recursos en la comunidad de peces, muestran que sus componentes están organizados en tres gremios: Ictiófagos, Carcinófagos y Omnívoros. Sin Röpke, Cristhiana P; Amadio, Sidinéia; Zuanon, Jansen; Ferreira, Efrem J G; Deus, Cláudia Pereira de; Pires, Tiago H S; Winemiller, Kirk O Combined effects of climate change and deforestation have altered precipitation patterns in the Amazon. This has led to changes in the frequency of extreme events of flood and drought in recent decades and in the magnitude of the annual flood pulse, a phenomenon that influences virtually all aspects of river-floodplain ecosystem dynamics. Analysis of long-term data revealed abrupt and synchronous changes in hydrology and fish assemblage structure of a floodplain lake near the confluence of Amazon and Negro rivers. After an intense drought in 2005, the assemblage assumed a different and fairly persistent taxonomic composition and functional structure. Declines in abundance after 2005 were more pronounced for species of all sizes having equilibrium life history strategy, large species with periodic life history strategy, and for all trophic levels except primary consumers. Our results suggest that the extreme drought triggered changes in the fish assemblage and subsequent anomalous hydrological conditions have hampered assemblage recovery. These findings stress the need to account for climatic-driven hydrological changes in conservation efforts addressing aquatic biodiversity and fishery resources in the central Amazon. Esselman, P.C.; Freeman, Mary C.; Pringle, C.M. Linkages between geology and fish assemblages have been inferred in many regions throughout the world, but no studies have yet investigated whether fish assemblages differ across geologies in Mesoamerica. The goals of our study were to: 1) compare physicochemical conditions and fish-assemblage structure across 2 geologic types in headwaters of the Monkey River Basin, Belize, and 2) describe basin-scale patterns in fish community composition and structure for the benefit of conservation efforts. We censused headwater-pool fishes by direct observation, and assessed habitat size, structure, and water chemistry to compare habitat and fish richness, diversity, evenness, and density between streams in the variably metamorphosed sedimentary geologic type typical of 80% of Belize's Maya Mountains (the Santa Rosa Group), and an anomalous extrusive geologic formation in the same area (the Bladen Volcanic Member). We also collected species-presence data from 20 sites throughout the basin for analyses of compositional patterns from the headwaters to the top of the estuary. Thirty-nine fish species in 21 families were observed. Poeciliids were numerically dominant, making up 39% of individuals captured, followed by characins (25%), and cichlids (20%). Cichlidae was the most species-rich family (7 spp.), followed by Poeciliidae (6 spp.). Habitat size and water chemistry differed strongly between geologic types, but habitat diversity did not. Major fish-assemblage differences also were not obvious between geologies, despite a marked difference in the presence of the aquatic macrophyte, Marathrum oxycarpum (Podostemaceae), which covered 37% of the stream bottom in high-nutrient streams draining the Santa Rosa Group, and did not occur in the low-P streams draining the Bladen Volcanic Member. Correlation analyses suggested that distance from the sea and amount of cover within pools are important to fish-assemblage structure, but that differing abiotic factors may influence Albouy, Camille; Guilhaumon, François; Bastos Araujo, Miguel future climatic niches of 288 coastal Mediterranean fish species based on a global warming scenario. We then aggregated geographically the species-level projections to analyse the projected changes in species richness and composition. Our results show that projected changes in assemblage composition....... nestedness), separately. We also present a mapping strategy to simultaneously visualize changes in species richness and assemblage composition. To illustrate our approach, we used the Mediterranean coastal fish fauna as a case study. Using Bioclimatic Envelope Models (BEMs) we first projected the potential......, the joint exploration of changes in species richness and composition coupled with the distinction between species replacement and nestedness bears important information for understanding the nature of climate change impacts on biodiversity. These methodological advances should help decision... Benejam, Lluis; Angermeier, Paul L.; Munne, Antoni; García-Berthou, Emili 1. Water abstraction strongly affects streams in arid and semiarid ecosystems, particularly where there is a Mediterranean climate. Excessive abstraction reduces the availability of water for human uses downstream and impairs the capacity of streams to support native biota. 2. We investigated the flow regime and related variables in six river basins of the Iberian Peninsula and show that they have been strongly altered, with declining flows (autoregressive models) and groundwater levels during the 20th century. These streams had lower flows and more frequent droughts than predicted by the official hydrological model used in this region. Three of these rivers were sometimes dry, whereas there were predicted by the model to be permanently flowing. Meanwhile, there has been no decrease in annual precipitation. 3. We also investigated the fish assemblage of a stream in one of these river basins (Tordera) for 6 years and show that sites more affected by water abstraction display significant differences in four fish metrics (catch per unit effort, number of benthic species, number of intolerant species and proportional abundance of intolerant individuals) commonly used to assess the biotic condition of streams. 4. We discuss the utility of these metrics in assessing impacts of water abstraction and point out the need for detailed characterisation of the natural flow regime (and hence drought events) prior to the application of biotic indices in streams severely affected by water abstraction. In particular, in cases of artificially dry streams, it is more appropriate for regulatory agencies to assign index scores that reflect biotic degradation than to assign ‘missing’ scores, as is presently customary in assessments of Iberian streams. Demarques Ribeiro da Silva Junior; Sérgio Ricardo Santos; Marcelo Travassos; Marcelo Vianna Dredging and dredge-spoil disposal are among the major problems in coastal management. Many of the scientific contributions concerning the impacts of this practice are based on the study of sessile organisms and subtropical environments. We evaluated changes in the composition and abundance of a fish assemblage resulting from dredging and sediment disposal at the mouth and in the adjacent waters of the Caravelas River on the north-eastern coast of Brazil. Samples were collected in two directl... White, Seth M.; Ondračková, Markéta; Reichard, Martin Roč. 44, č. 4 (2012), s. 521-530 ISSN 0006-3606 R&D Projects: GA AV ČR IAA6093404 Institutional research plan: CEZ:AV0Z60930519 Institutional support: RVO:68081766 Keywords : fish assemblage * functional morphology * large tropical river s * lateral migration * multivariate analysis * pre-impoundment * reference condition * trophic position Subject RIV: EH - Ecology, Behaviour Impact factor: 2.351, year: 2012 Milbrandt, Eric C.; Bartleson, Richard D.; Coen, Loren D.; Rybak, Olexandr; Thompson, Mark A.; DeAngelo, Jacquelyn A.; Stevens, Philip W. Blind Pass is an inlet that separates Sanibel and Captiva Islands in southwest Florida but has historically closed and opened by both anthropogenic and natural processes. In July 2010, a dredging project to open the small inlet between the two barrier islands was completed. The objective of this study was to use and supplement ongoing estuary-monitoring programs to examine the responses of water quality, seagrass habitat metrics, and fish assemblages both in the immediate vicinity of the inlet and at broader scales (up to 40 km2). As far as we are aware, there are no previous studies with this intensity of sampling, both before and after an inlet opening. Significant increases in salinity and turbidity were observed inside Blind Pass, with significant decreases in CDOM and chlorophyll a, however, the effects were not far-reaching and limited to less than 1.7 km from the inlet within Pine Island Sound. Seagrass habitat metrics were expected to respond rapidly after the inlet was opened given the reduced light attenuation. However, there were no changes in shoot densities, species composition, and epiphytic algae within the approximately one-year duration of the study. The reopening of the pass did not substantially change fish assemblage structure, except for those from deeper habitats. Although immediate increases in the abundances of estuarine-dependent species were predicted in shallow habitats post opening, this did not occur. In conclusion, the effects of reopening a relatively small ocean inlet on water quality were apparent in the immediate vicinity of the inlet (within 1.7 km), but far-reaching effects on water quality, seagrass metrics, and fish assemblages were not immediately apparent in this well-flushed estuary. If subtle changes in tidal exchange and circulation affect productivity of seagrasses or its fish assemblages at broad scales, it may take several years to reach a steady state. Netburn, Amanda N.; Koslow, J. Anthony With strong horizontal gradients in physical properties, oceanic frontal regions can lead to disproportionately high biological productivity. We examined cross-frontal changes in mesopelagic fish assemblages at three separate frontal systems in the southern California Current Ecosystem (CCE) as part of the CCE Long Term Ecological Research program: the A-Front sampled in October 2008, the C-Front in June/July 2011, and the E-Front in July/August 2012. We analyzed the differential effects of front-associated regions on density and species composition of adult migratory and non-migratory fishes and larvae, and the larval to adult ratio (as a possible index of a population growth potential) for migratory and non-migratory species. The fronts did not have a strong effect on densities of any subset of the mesopelagic fish assemblage. The species composition of the vertical migratory fishes (and their larvae) was typically altered across fronts, with different assemblages present on either side of each front. The migratory assemblages at the fronts themselves were indistinguishable from those at the more productive side of the frontal system. In contrast, the assemblage composition of the non-migratory fishes was indistinguishable between regions across all three of the fronts. The differences between the Northern and Southern assemblages at the A-Front were primarily based on biogeographic provinces, while the assemblages at the E-Front were largely distinguishable by their oceanic or coastal-upwelling zone associations. These results generally confirm those of previous studies on frontal systems in the California Current Ecosystem and elsewhere. The ratio of larvae to adults, a potential index of population growth potential, was altered across two of the fronts for migratory species, elevated on the colder side of the A-Front and the warmer side of the E-Front. This finding suggests that fronts may be regions of enhanced reproduction. The larvae to adult ratio was Carlos Edwar de C. Freitas Full Text Available We conducted a study to test the hypothesis that interconnectedness among island floodplain lakes and the adjacent Solimões River during the flood stage of the hydrologic cycle is enough to maintain similarity in fish species assemblages. Gill net samples were collected during high and low water periods for three consecutive years (July 2004 to July 2006 in four lakes on Paciência Island. Two lakes, Piranha and Ressaca, are connected to the river all year, and the other two, Preto and Cacau, which are in the center of the island, are isolated during low water periods. The abundance, species richness and evenness of the fish assemblages in these lakes did not differ according to their relative positions or the season of the hydrological cycle, which confirmed our hypothesis. However, fish abundance during the dry season was greater than in the flood season. Apparently, the short period of full connection between the lakes is enough to allow the colonization of all fish species, but not to cause similar abundances. Our study indicates that persistence of the species composition of island floodplain lakes is primarily due to the annual replenishment of fish to the lakes during the flood season. Thorman, Staffan; Wiederholm, Anne-Marie A nearshore fish assemblage inhabiting a shallow bay in the southern Bothnian Sea, Sweden, with demanding environmental conditions (c. 5‰; >15°C during 4 months 1980 and 1 month 1981) was studied during a two-year period, in 1980 and 1981. Seasonal distribution patterns, dietary relationships, and growth rates were studied in Pungitius pungitius (L.), Pomatoschistus minutus (Pallas.), Gasterosteus aculeatus (L.), Phoxinus phoxinus (L.), Pomatoschistus microps (Krøyer) and Gobius niger L. The structure of the juvenile populations changed both over seasons and years but the adult populations remained constant. Lower water temperature, fewer individuals, lower and delayed fish growth, and lower interspecific food overlaps were found in 1981 compared to 1980. Few significant correlations were found in both years between the following community parameters: diversity, niche width, food overlap, and the proportion of each species in the fish assemblage. According to these results it is suggested that food competition and resource partitioning were of minor importance for the structuring of the fish community in the present area. Rather, the extreme salinity and the fluctuations in temperature regulated the fish populations. One may conclude that the populations of juveniles were more influenced by short-term changes in the environment than those of the adults. Schinegger, Rafaela; Pucher, Matthias; Aschauer, Christiane; Schmutz, Stefan This work addresses multiple human stressors and their impacts on fish assemblages of the Drava and Mura rivers in southern Austria. The impacts of single and multiple human stressors on riverine fish assemblages in these basins were disentangled, based on an extensive dataset. Stressor configuration, i.e. various metrics of multiple stressors belonging to stressor groups hydrology, morphology, connectivity and water quality were investigated for the first time at river basin scale in Austria. As biological response variables, the Fish Index Austria (FIA) and its related single as well as the WFD biological- and total state were investigated. Stressor-response analysis shows divergent results, but a general trend of decreasing ecological integrity with increasing number of stressors and maximum stressor is observed. Fish metrics based on age structure, fish region index and biological status responded best to single stressors and/or their combinations. The knowledge gained in this work provides a basis for advanced investigations in Alpine river basins and beyond, supports WFD implementation and helps prioritizing further actions towards multi-stressor restoration- and management. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved. Ceccarelli, Daniela M; Emslie, Michael J; Richards, Zoe T Quantifying changes to coral reef fish assemblages in the wake of cyclonic disturbances is challenging due to spatial variability of damage inherent in such events. Often, fish abundance appears stable at one spatial scale (e.g. reef-wide), but exhibits substantial change at finer scales (e.g. site-specific decline or increase). Taxonomic resolution also plays a role; overall stability at coarse taxonomic levels (e.g. family) may mask species-level turnover. Here we document changes to reef fish communities after severe Tropical Cyclone Ita crossed Lizard Island, Great Barrier Reef. Coral and reef fish surveys were conducted concurrently before and after the cyclone at four levels of exposure to the prevailing weather. Coral cover declined across all exposures except sheltered sites, with the largest decline at exposed sites. There was no significant overall reduction in the total density, biomass and species richness of reef fishes between 2011 and 2015, but individual fish taxa (families and species) changed in complex and unpredictable ways. For example, more families increased in density and biomass than decreased following Cyclone Ita, particularly at exposed sites whilst more fish families declined at lagoon sites even though coral cover did not decline. All sites lost biomass of several damselfish species, and at most sites there was an increase in macroinvertivores and grazers. Overall, these results suggest that the degree of change measured at coarse taxonomic levels masked high species-level turnover, although other potential explanations include that there was no impact of the storm, fish assemblages were impacted but underwent rapid recovery or that there is a time lag before the full impacts become apparent. This study confirms that in high-complexity, high diversity ecosystems such as coral reefs, species level analyses are essential to adequately capture the consequences of disturbance events. Juan José Neiff Full Text Available In this paper, we analyze the changes in composition and abundance of fish assemblages in seven vegetated floodplain wetlands with different connectivity across different hydrologic conditions: after a prolonged connection of the floodplain with the main channel, during receding water, and after a prolonged isolation. We also investigated the size and abundance of large-sized migratory species found in these wetlands and the food resources exploited by the dominant fish. Fishes were captured by diurnal seining (8.0 m x 1.50 m, 5 mm mesh along macrophyte banks. Despite the high total number of species registered (100, sample species richness varied between 7 and 31, depending on the sampling site and the sampling date. Cluster analysis indicated low similarity between sites during both the isolation and the prolonged connection. Species turnover decreased from high water (β = 40.33 to low water (β = 33.83, with the minimum value of beta diversity index obtained during the isolation of the floodplain wetlands (β = 26.83. Our results indicated that different dominant populations of fish occur in different hydrological conditions, even though high water and isolation phases occur in the same season of different years. The ordination (NMDS indicated the importance of hydrologic conditions in structuring fish assemblages in the studied floodplain. Small-sized characids, typically associated with macrophytes, dominated the fish assemblages, whereas the younger stages of large sized migratory species were found in low abundance. The maximum standard length of the fish captured was 28 cm and for large migratory fish, standard length varied between 1.6 and 25.0 cm. The dominant fish used several food resources, but littoral macrophytes-associated organisms had a high frequency of occurrence in the three hydrologic conditions. The high species richness of fish in the small, vegetated lakes was related to the high spatial heterogeneity during different Parker, Melanie L.; Fraser, William R.; Ashford, Julian; Patarnello, Tomaso; Zane, Lorenzo; Torres, Joseph J. Micronektonic fishes and invertebrates were sampled with 32 midwater trawls at nine sites along the Western Antarctic Peninsula (WAP) in the austral fall (March-April) of 2010. Study sites were located within four hypothesized hydrographic regions: near Joinville Island in Region I, at Croker Passage, near Anvers Island, and near Renaud Island in Region II, within Marguerite Bay and the Marguerite Trough in Region III, and near Charcot Island in Region IV. A total of 62 taxa representing 12 taxonomic groups of pelagic invertebrates and 9 families of fish were captured, but assemblages were dominated by only a few species. The most numerically abundant taxa were the euphausiids, Thysanoessa macrura, Euphausia superba, and E. crystallorophias, combining to contribute nearly 79% of the total catch. Biomass dominants included E. superba, which contributed more than 44% of the total catch, the notothenioid Pleuragramma antarctica, and the salp, Salpa thompsoni. A comparison of total catches among sites revealed that the largest volumetric abundances and biomasses were captured at the Marguerite Bay site. Cluster analysis of abundance data identified distinct multispecies assemblages at Joinville Island in Region I, Croker Passage in Region II, Marguerite Bay in Region III, and Charcot Island in Region IV. A fifth distinct assemblage included samples from sites near Anvers and Renaud Island in Region II, and from the Marguerite Trough in Region III. Assemblages at Joinville Island and Croker Passage were both dominated by E. superba and S. thompsoni, but hydrographic conditions at Joinville Island favored a neritic assemblage, underscored by substantial numbers of P. antarctica. The assemblage at Croker Passage was more oceanic in nature with major inputs from the myctophid, Electrona antarctica and the hyperiid amphipod, Themisto gaudichaudii. Marguerite Bay and Charcot Island were well-mixed assemblages with strong representation by both neritic and oceanic fauna. The André Araújo Lima Full Text Available Seasonality was a stronger influence in the ichthyoplankton assemblages around the Saint Peter and Saint Paul Archipelago (SPSPA than distance from the islands. Plastic debris were ubiquitous and although it presented diel trends, no other spatiotemporal patterns was showed. Larval Oxyporhamphus micropterus was the most important taxa (29.37% of the total catch, followed by Ceratoscopelus warmingii and Entomacrodus vomerianus. Exocoetidae eggs represented 41.01%. Mesopelagic fish larvae dominated the community. Myctophidae had the highest species richness (15. Four larval fish assemblages occured: (1 nighttime demersal/bathydemersal (Anguillidae, Congridae; (2 daytime mesopelagic/bathypelagic/epipelagic (Myctophidae, Cyclothone acclinidens; (3 daytime epipelagic (Exocoetidae, Coryphaena hippurus, Thunnus albacares and (4 nighttime reef and demersal (Blennidae, Pomacentridae, Lutjanidae. The dry season (lower temperature, higher chlorophyll a and higher SW wind velocity influenced the first two assemblages. The rainy season (higher temperatures and lower NW wind velocity influenced the last two. Nighttime abundance of dominant species in the rainy season suggests diel vertical migration nearshore. Plastics were 2.12 times more abundant than the most abundant fish larvae. Comparable amounts of larvae and plastics in the water column increase the chances of interaction between these two compartments and might disturb the local marine food web and promote the transfer of microplastic from one habitat to another, especially when smaller taxa contaminated by ingested fragments are preyed by migratory animals such as marine birds and tuna. A study around the area concluded that at least a part of the plastic debris can have local source due to fishing activities. Small-scale oceanographic mechanisms such as the interaction between the topography and currents (SEC and EUC seem to be responsible for the retention of fish eggs, fish larvae and plastics Schinegger, Rafaela; Palt, Martin; Segurado, Pedro; Schmutz, Stefan This work addresses human stressors and their impacts on fish assemblages at pan-European scale by analysing single and multiple stressors and their interactions. Based on an extensive dataset with 3105 fish sampling sites, patterns of stressors, their combination and nature of interactions, i.e. synergistic, antagonistic and additive were investigated. Geographical distribution and patterns of seven human stressor variables, belonging to four stressor groups (hydrological-, morphological-, water quality- and connectivity stressors), were examined, considering both single and multiple stressor combinations. To quantify the stressors' ecological impact, a set of 22 fish metrics for various fish assemblage types (headwaters, medium gradient rivers, lowland rivers and Mediterranean streams) was analysed by comparing their observed and expected response to different stressors, both acting individually and in combination. Overall, investigated fish sampling sites are affected by 15 different stressor combinations, including 4 stressors acting individually and 11 combinations of two or more stressors; up to 4 stressor groups per fish sampling site occur. Stressor-response analysis shows divergent results among different stressor categories, even though a general trend of decreasing ecological integrity with increasing stressor quantity can be observed. Fish metrics based on density of species 'intolerant to water quality degradation' and 'intolerant to oxygen depletion" responded best to single and multiple stressors and their interactions. Interactions of stressors were additive (40%), synergistic (30%) or antagonistic (30%), emphasizing the importance to consider interactions in multi-stressor analyses. While antagonistic effects are only observed in headwaters and medium-gradient rivers, synergistic effects increase from headwaters over medium gradient rivers and Mediterranean streams to large lowland rivers. The knowledge gained in this work provides a basis for Kennen, Jonathan G.; Riskin, Melissa L. Changes in water demand associated with population growth and changes in land-use practices in the Pinelands region of southern New Jersey will have a direct effect on stream hydrology. The most pronounced and measurable hydrologic effect is likely to be flow reductions associated with increasing water extraction. Because water-supply needs will continue to grow along with population in the Pinelands area, the goal of maintaining a sustainable balance between the availability of water to protect existing aquatic assemblages while conserving the surficial aquifer for long-term support of human water use needs to be addressed. Although many aquatic fauna have shown resilience and resistance to short-term changes in flows associated with water withdrawals, sustained effects associated with ongoing water-development processes are not well understood. In this study, the U.S. Geological Survey sampled forty-three 100-meter-long stream reaches during high- and low-flow periods across a designed hydrologic gradient ranging from small- (4.1 square kilometers (1.6 square miles)) to medium- (66.3 square kilometers (25.6 square miles)) sized Pinelands stream basins. This design, which uses basin size as a surrogate for water availability, provided an opportunity to evaluate the possible effects of potential variation in stream hydrology on fish and aquatic-invertebrate assemblage response in New Jersey Pinelands streams where future water extraction is expected based on known build-out scenarios. Multiple-regression models derived from extracted non-metric multidimensional scaling axis scores of fish and aquatic invertebrates indicate that some variability in aquatic-assemblage composition across the hydrologic gradient is associated with anthropogenic disturbance, such as urbanization, changes in stream chemistry, and concomitant changes in high-flow runoff patterns. To account for such underlying effects in the study models, any flow parameter or assemblage attribute that Rodrigo Assis Carvalho Full Text Available We investigated functional patterns of fish assemblages of two adjacent basins (Araguaia and Tocantins to test whether their headwater stream fish assemblages are more functionally (dissimilar than expected by chance and whether these (dissimilarities are related to differences of environmental conditions between basins. We used an analysis of similarities (ANOSIM on a functional dissimilarity matrix to test for (dissimilarities between fish assemblages of both basins. We performed RLQ and fourth-corner analyses to determine fish species trait-environment relationship. Our results revealed functional dissimilarities between fish assemblages of both basins and significant species trait-environment relationships, suggesting that environmental conditions are driving such dissimilarities. Inter-basin dissimilarities are mainly driven by altitudinal and water temperature gradients, whereas dissimilarities among streams within the basins are influenced by channel depth, turbidity and conductivity. These five environmental variables mostly affected six fish species traits (body mass, water column position, substrate preference, parental care, foraging locality and migration in different manners. This study is an attempt to understand functional trends of fish assemblages in a tropical region that remains poorly known but severely threatened. Contente, Riguel Feltrin; Del Bianco Rossi-Wongtschowski, Carmen Lucia The use of multiple sampling gears is indispensible to obtain robust characterizations of fish assemblage structure in species-rich subtropical ecosystems. In this study, such a dependence was demonstrated by characterizing the structure of the high-tide fish assemblage in a subtropical tidal flat ecosystem (the Araçá Bay, southeastern Brazil) using eight different gears along five seasonal surveys and estimating the bay's fish species richness, combining these data with those from local tide pool fish surveys. The high-tide fish assemblage was spatially structured, contained five threatened species, and was dominated by persistent and large populations of Eucinostomus argenteus and of the fisheries species Mugil curema and Diapterus rhombeus that intensively use the bay throughout their life cycles. Large, small-bodied fish populations supported a regular use of the bay by piscivores. The autumn-winter peak in abundance of juvenile fishes caused a subsequent increase in piscivore abundance, and both events explained the bulk of the seasonal variability of the fish assemblage. The estimated richness revealed that the combination of sampling methods was enough for sampling the bulk of the local richness, and the bay may hold a surprisingly high richness compared to other costal ecosystem of the region. This faunal characterization, only viable using multiple gears, will be critical to support the implementation of a future study to monitor the impacts on local fish biodiversity of an imminent port expansion over the tidal flat. Saïkou Oumar Kidé Full Text Available Environmental changes and human activities can have strong impacts on biodiversity and ecosystem functioning. This study investigates how, from a quantitative point of view, simultaneously both environmental and anthropogenic factors affect species composition and abundance of exploited groundfish assemblages (i.e. target and non-target species at large spatio-temporal scales. We aim to investigate (1 the spatial and annual stability of groundfish assemblages, (2 relationships between these assemblages and structuring factors in order to better explain the dynamic of the assemblages' structure. The Mauritanian Exclusive Economic Zone (MEEZ is of particular interest as it embeds a productive ecosystem due to upwelling, producing abundant and diverse resources which constitute an attractive socio-economic development. We applied the multi-variate and multi-table STATICO method on a data set consisting of 854 hauls collected during 14-years (1997-2010 from scientific trawl surveys (species abundance, logbooks of industrial fishery (fishing effort, sea surface temperature and chlorophyll a concentration as environmental variables. Our results showed that abiotic factors drove four main persistent fish assemblages. Overall, chlorophyll a concentration and sea surface temperature mainly influenced the structure of assemblages of coastal soft bottoms and those of the offshore near rocky bottoms where upwellings held. While highest levels of fishing effort were located in the northern permanent upwelling zone, effects of this variable on species composition and abundances of assemblages were relatively low, even if not negligible in some years and areas. The temporal trajectories between environmental and fishing conditions and assemblages did not match for all the entire time series analyzed in the MEEZ, but interestingly for some specific years and areas. The quantitative approach used in this work may provide to stakeholders, scientists and fishers a Taylor, D.S.; Reyier, E.A.; Davis, W.P.; McIvor, C.C. We investigated the effects of mangrove cutting on fish assemblages in Twin Cays, Belize, in two habitat types. We conducted visual censuses at two sites in adjoining undisturbed/disturbed (30%–70% of shoreline fringe removed) sub-tidal fringing Rhizophora mangle Linnaeus, 1753. Observers recorded significantly more species and individuals in undisturbed sites, especially among smaller, schooling species (e.g., atherinids, clupeids), where densities were up to 200 times greater in undisturbed habitat. Multivariate analyses showed distinct species assemblages between habitats at both sites. In addition, extensive trapping with wire minnow traps within the intertidal zone in both undisturbed and disturbed fringing and transition (landward) mangrove forests was conducted. Catch rates were low: 638 individuals from 24 species over 563 trap-nights. Trap data, however, indicated that mangrove disturbance had minimal effect on species composition in either forest type (fringe/transition). Different results from the two methods (and habitat types) may be explained by two factors: (1) a larger and more detectable species pool in the subtidal habitat, with visual "access" to all species, and (2) the selective nature of trapping. Our data indicate that even partial clearing of shoreline and more landward mangroves can have a significant impact on local fish assemblages. Mosepele, K.; Mosepele, B.; Bokhutlo, T.; Amutenya, K. The species assemblage and community structure of four lagoons was assessed through time series data collected between 2001 and 2005 in the Okavango Delta. The main aim of this study was to evaluate the importance of lagoons as fish habitats in the Delta. Therefore, this study assessed the importance of these habitats through determining fish species diversity, composition, relative abundance, and community structure between the lagoons. Forty six species belonging to 11 families and five orders were collected over the study period. Main results showed that Cichlidae was the most important family and had the highest species richness in the lagoons. Significant differences ( p lodges are constructed, which makes subsequently makes them vulnerable to pollution. Therefore, the integrity of lagoon habitats needs to be maintained so that their ecosystem functioning (i.e. fish repositories) is maintained. Mont'Alverne, R; Pereyra, P E R; Garcia, A M Stable isotopes were used to evaluate the hypothesis that fish assemblages occurring in shallow and deep areas of a large coastal lagoon are structured in partially segregated trophic modules with consumers showing contrasting reliance on benthic or pelagic food sources. The results revealed that fishes in deep areas were mainly dependent on particulate organic matter in the sediment (SOM), whereas emergent macrophytes were as important as SOM to fish consumers in shallow areas. Conceptual trophic diagrams depicting relationships among basal food sources and consumers in different regions of the lagoon highlighted the greater use of multiple basal food sources by more feeding mode functional guilds in shallow water compared with the use of predominantly benthic resources (SOM) in deep areas. The findings appear to corroborate the initial hypothesis and offer complementary perspectives in understanding the role of spatial ecology in structuring coastal ecosystem function and productivity. © 2016 The Fisheries Society of the British Isles. George, Scott D.; Baldigo, Barry P.; Wells, Scott M The Mohawk River and New York State Barge Canal run together as a series of permanent and temporary impoundments for most of the distance between Rome and Albany, New York. The downstream or lower section is composed of two permanent impoundments, the middle section of a series of temporary (seasonal) impoundments, and the upper section of a series of permanent impoundments. In the middle section, movable dams are lifted from the water during winter and the wetted surface area decreases by 36–56%. We used boat electrofishing during spring 2014 and 2015 to compare the relative abundance of fish populations and the composition of fish assemblages between the permanently and seasonally impounded sections of the Barge Canal and to infer the effects of the two flow management practices. A total of 3,264 individuals from 38 species were captured, and total catch per unit effort (CPUE) ranged from 46.0 to 134.7 fish/h at sites in the seasonally impounded section, compared with 140.0–342.0 fish/h in the permanent lower section and 89.0–282.0 fish/h in the permanent upper section. The amount of drawdown explained 55% of the variation in total CPUE and was a highly significant predictor variable. Mean total CPUE in the seasonally impounded section was significantly lower (by about 50%) than that in either permanently impounded section, and the assemblage composition differed significantly between sections. The relative abundance of many lentic species was markedly lower in the seasonally impounded section, while the relative abundance of several native cyprinids and the percentage of individuals belonging to species that are native to the watershed was greater in this section. Overall, these findings suggest that winter dam removal in impounded rivers may reduce the abundance of fish but may also create more natural riverine conditions that favor some native species. Full Text Available Fish assemblage structure and variability were analyzed in two floodplain lagoons (Las Arhuacas and Los Cardonales along the lower Orinoco over a hydrological cycle. Every three months during continuous three-day sampling, experimental gill nets (5 to 12.5 cm of mesh opening and 1 mm-mesh seine nets were utilized according to the types of habitats presents. A total of 133 fish species were found in Las Arhuacas and 95 species in Cardonales. Fifty five and 17 species were exclusive to Las Arhuacas and Los Cardonales respectively, and 77 were common to both lagoons. In Las Arhuacas, the most speciesrich orders were Characiformes, Siluriformes, Perciformes and Gymnotiformes and in Los Cardonales, the most species-rich orders were Characiformes, Siluriformes, Clupeiformes and Perciformes. The richness, abundance and biomass were significantly higher (p < 0.001 in Arhuacas than in Cardonales. In general, the fishes assemblage was highly variable during the high water phase and moderately stable during low water phase in both lagoons, with more stability or less variability in Cardonales than Arhuacas. Also, there were significant differences in the fish assemblages between the two lagoons, mainly during low waters (ANOSIM; p < 0.001. The species that contributed most to the mean dissimilarity between the lagoons were Hypostomus argus, Aphanotorulus ammophilus, Potamorhina altamazonica, Prochilodus mariae, Loricaria gr. cataphracta, Oxydoras sifontesi, Hydrolycus armatus, Hyphopthalmus edentatus and Pterodoras rivasi. The last four species were more commonly collected in Los Cardonales. Also, the species of small size (mainly SL < 5 cm such as Rhinosardinia amazonica, Moenkhausia sp. 1 "lepidura", Moenkhausia sp. 2, Aphyocharax alburnus, Characidium sp. 1, Moenkhausia sp. 3, Exodon paradoxus and Roeboides dientonito contributed to the mean dissimilarity among the beach and aquatic vegetation habitats. The patterns of the species assemblage Siziba, Nqobizitha; Chimbari, Moses J.; Masundire, Hillary; Mosepele, Ketlhatlogile; Ramberg, Lars Water extraction from floodplain river systems may alter patterns of inundation of adjacent wetlands and lead to loss of aquatic biodiversity. Water reaching the Okavango Delta (Delta), Botswana, may decrease due to excessive water extraction and climate change. However, due to poor understanding of the link between inundation of wetlands and biological responses, it is difficult to assess the impacts of these future water developments on aquatic biota. Large floods from 2009 to 2011 inundated both rarely and frequently flooded wetlands in the Delta, creating an opportunity to examine the ecological significance of flooding of wetlands with widely differing hydrological characteristics. We studied the assemblages of small fishes and microcrustaceans, together with their trophic relationships, in temporary wetlands of the lower Delta. Densities of microcrustaceans in temporary wetlands were generally lower than previously recorded in these habitats. Microcrustacean density varied with wetland types and hydrological phase of inundation. High densities of microcrustaceans were recorded in the 2009 to 2010 flooding season after inundation of rarely flooded sites. Large numbers of small fishes were observed during this study. Community structure of small fishes differed significantly across the studied wetlands, with poeciliids predominant in frequently flooded wetlands and juvenile cichlids most abundant in rarely flooded wetlands (analysis of similarity, P < 0.05). Small fishes of <20 mm fed largely on microcrustaceans and may have led to low microcrustacean densities within the wetlands. This result matched our prediction that rarely flooded wetlands would be more productive; hence, they supported greater populations of microcrustaceans and cichlids, which are aggressive feeders. However, the predominance of microcrustaceans in the guts of small fishes (<20 mm) suggests that predation by fishes may also be an important regulatory mechanism of microcrustacean Miguel Angel Peralta-Meixueiro Full Text Available The spatial and temporal fish species assemblages were analyzed throughout two annual cycles (2004-2005 and 2007-2008 in the Ría Lagartos Lagoon system, Mexico, via non-parametric multivariate analyses. We compared density and biomass of fish species among five habitat types defined by combinations of structure and environmental characteristics (hyperhaline, rocky, seagrass, channel, and marine, and three climatic seasons (dry, rainy, and northerlies. A total of 11,187 individuals distributed in 32 families and 63 species were collected. The most numerically abundant species were Floridichthys polyommus and Cyprinodon artifrons, while Sphoeroides testudineus contributed to the greatest biomass. Species composition consisted mainly of estuarine and euryhaline marine species. Spatially, a saline gradient was observed with marine conditions in the mouth, and increasing to over 100 in the inner zone of the system. Species richness, diversity and biomass declined from the mouth to the inner zone, while density showed an inverse tendency, with the highest values in the inner zone. Thus the salinity was the variable that best explained the spatial fish assemblages" structure. The ichthyofauna composition did not change over time, but the dominant species varied with the years. The abundance of juvenile specimens, suggest that the different habitats are used as feeding and breeding zones; hence it is proposed that protection strategies be pursued not only for the lagoon system but also for the northern zone of the Yucatan Peninsula. Thomas, J.T.; Culler, M.E.; Dermisis, D.C.; Pierce, Clay; Papanicolaou, A.N.; Stewart, T.W.; Larson, C.J. Land use changes and channelization of streams in the deep loess region of western Iowa have led to stream channel incision, altered flow regimes, increased sediment inputs, decreased habitat diversity and reduced lateral connectivity of streams and floodplains. Grade control structures (GCSs) are built in streams to prevent further erosion, protect infrastructure and reduce sediment loads. However, GCS can have a detrimental impact on fisheries and biological communities. We review three complementary biological and hydraulic studies on the effects of GCS in these streams. GCS with steep (≥1:4 rise : run) downstream slopes severely limited fish passage, but GCS with gentle slopes (≤1:15) allowed greater passage. Fish assemblages were dominated by species tolerant of degradation, and Index of Biotic Integrity (IBI) scores were indicative of fair or poor biotic integrity. More than 50% of fish species had truncated distributions. After modification of GCS to reduce slopes and permit increased passage, IBI scores increased and several species were detected further upstream than before modification. Total macroinvertebrate density, biomass and taxonomic diversity and abundance of ecologically sensitive taxa were greater at GCS than in reaches immediately upstream, downstream or ≥1 km from GCS. A hydraulic study confirmed results from fish passage studies; minimum depths and maximum current velocities at GCS with gentle slopes (≤1:15) were more likely to meet minimum criteria for catfish passage than GCS with steeper slopes. Multidisciplinary approaches such as ours will increase understanding of GCS-associated factors influencing fish passage, biological assemblage structure and other ecological relationships in streams. Kalogianni, Eleni; Vourka, Aikaterini; Karaouzas, Ioannis; Vardakas, Leonidas; Laschou, Sofia; Skoulikidis, Nikolaos Th Water stress is a key stressor in Mediterranean intermittent rivers exacerbating the negative effects of other stressors, such as pollutants, with multiple effects on different river biota. The current study aimed to determine the response of macroinvertebrate and fish assemblages to instream habitat and water chemistry, at the microhabitat scale and at different levels of water stress and pollution, in an intermittent Mediterranean river. Sampling was conducted at high and low summer discharge, at two consecutive years, and included four reaches that were targeted for their different levels of water stress and pollution. Overall, the macroinvertebrate fauna of Evrotas River indicated high resilience to intermittency, however, variation in community structure and composition occurred under acute water stress, due to habitat alteration and change in water physico-chemistry, i.e. water temperature increase. The combined effects of pollution and high water stress had, however, pronounced effects on species richness, abundance and community structure in the pollution impacted reach, where pollution sensitive taxa were almost extirpated. Fish response to drought, in reaches free of pollution, consisted of an increase in the abundance of the two small limnophilic species, coupled with their shift to faster flowing riffle habitats, and a reduction in the abundance of the larger, rheophilic species. In the pollution impacted reach, however, the combination of pollution and high water stress led to hypoxic conditions assumed to be the leading cause of the almost complete elimination of the fish assemblage. In contrast, the perennial Evrotas reaches with relatively stable physicochemical conditions, though affected hydrologically by drought, appear to function as refugia for fish during high water stress. When comparing the response of the two biotic groups to combined acute water stress and pollution, it is evident that macroinvertebrates were negatively impacted, but fish Snickars, Martin; Sandström, Alfred; Lappalainen, Antti; Mattila, Johanna; Rosqvist, Kajsa; Urho, Lauri The assemblages of young-of-the-year fish were studied in coastal lagoons in an archipelago with post-glacial land-uplift, which affects environmental gradients at local and regional scale, i.e. lagoon habitat isolation and archipelago position, respectively. The categorisation of 40 undisturbed lagoons into nine habitat types based on habitat isolation and archipelago position was supported by clear relationships with spring temperature and total fish abundance. Rutilus rutilus, breams ( Abramis/Blicca sp.) and Perca fluviatilis were the most abundant and frequently occurring species. The fish assemblage differed among the nine habitat types. Rutilus rutilus, P. fluviatilis and breams were discriminating species in the majority of habitat types with low physical harshness, whereas Alburnus alburnus and Gasterosteus aculeatus increased their contributions in habitat types with high physical harshness. Rutilus rutilus and breams were thus common in lagoons with high habitat isolation situated in the inner archipelago. These lagoons were characterised by warm water and high vegetation coverage. Gasterosteus aculeatus was restricted to lagoons with low habitat isolation and exposure and low vegetation coverage, situated in the outer archipelago. Perca fluviatilis had the widest distribution of all species. The coverage of two macrophytes, Potamogeton perfoliatus and Zannichellia palustris, and salinity matched best the distance among habitat types. These habitat characteristics, as well as the fish abundances and assemblages differed most across the habitat types in the outer and mid archipelago zones and in the lowest habitat isolation. These patterns suggest that the structuring effect of habitat isolation increases along the archipelago gradient as differences between local and regional conditions increase. In the inner archipelago, overall low physical harshness induces homogeneous conditions and the habitat isolation is less important here than in the other zones Waite, Ian R.; Casper, Andrew F.; Ward, David L.; Sauer, Jennifer S.; Irwin, Elise R.; Chapman, Colin G.; Ickes, Brian S.; Paukert, Craig P.; Kosovich, John J.; Bayer, Jennifer M. Understanding trends in the diverse resources provided by large rivers will help balance tradeoffs among stakeholders and inform strategies to mitigate the effects of landscape scale stressors such as climate change and invasive species. Absent a cohesive coordinated effort to assess trends in important large river resources, a logical starting point is to assess our ability to draw inferences from existing efforts. In this paper, we use a common analytical framework to analyze data from five disparate fish monitoring programs to better understand the nature of spatial and temporal trends in large river fish assemblages. We evaluated data from programs that monitor fishes in the Colorado, Columbia, Illinois, Mississippi, and Tallapoosa rivers using non-metric dimensional scaling ordinations and associated tests to evaluate trends in fish assemblage structure and native fish biodiversity. Our results indicate that fish assemblages exhibited significant spatial and temporal trends in all five of the rivers. We also document native species diversity trends that were variable within and between rivers and generally more evident in rivers with higher species richness and programs of longer duration. We discuss shared and basin-specific landscape level stressors. Having a basic understanding of the nature and extent of trends in fish assemblages is a necessary first step towards understanding factors affecting biodiversity and fisheries in large rivers. PMID:29364953 Counihan, Timothy D.; Waite, Ian R.; Casper, Andrew F.; Ward, David L.; Sauer, Jennifer S.; Irwin, Elise R.; Chapman, Colin G.; Ickes, Brian; Paukert, Craig P.; Kosovich, John J.; Bayer, Jennifer M. Understanding trends in the diverse resources provided by large rivers will help balance tradeoffs among stakeholders and inform strategies to mitigate the effects of landscape scale stressors such as climate change and invasive species. Absent a cohesive coordinated effort to assess trends in important large river resources, a logical starting point is to assess our ability to draw inferences from existing efforts. In this paper, we use a common analytical framework to analyze data from five disparate fish monitoring programs to better understand the nature of spatial and temporal trends in large river fish assemblages. We evaluated data from programs that monitor fishes in the Colorado, Columbia, Illinois, Mississippi, and Tallapoosa rivers using non-metric dimensional scaling ordinations and associated tests to evaluate trends in fish assemblage structure and native fish biodiversity. Our results indicate that fish assemblages exhibited significant spatial and temporal trends in all five of the rivers. We also document native species diversity trends that were variable within and between rivers and generally more evident in rivers with higher species richness and programs of longer duration. We discuss shared and basin-specific landscape level stressors. Having a basic understanding of the nature and extent of trends in fish assemblages is a necessary first step towards understanding factors affecting biodiversity and fisheries in large rivers. Stephen J Jacquemin Full Text Available We combine evolutionary biology and community ecology to test whether two species traits, body size and geographic range, explain long term variation in local scale freshwater stream fish assemblages. Body size and geographic range are expected to influence several aspects of fish ecology, via relationships with niche breadth, dispersal, and abundance. These traits are expected to scale inversely with niche breadth or current abundance, and to scale directly with dispersal potential. However, their utility to explain long term temporal patterns in local scale abundance is not known. Comparative methods employing an existing molecular phylogeny were used to incorporate evolutionary relatedness in a test for covariation of body size and geographic range with long term (1983 - 2010 local scale population variation of fishes in West Fork White River (Indiana, USA. The Bayesian model incorporating phylogenetic uncertainty and correlated predictors indicated that neither body size nor geographic range explained significant variation in population fluctuations over a 28 year period. Phylogenetic signal data indicated that body size and geographic range were less similar among taxa than expected if trait evolution followed a purely random walk. We interpret this as evidence that local scale population variation may be influenced less by species-level traits such as body size or geographic range, and instead may be influenced more strongly by a taxon's local scale habitat and biotic assemblages. Lallement, Mailén; Macchi, Patricio J; Vigliano, Pablo; Juarez, Santiago; Rechencq, Magalí; Baker, Matthew; Bouwes, Nicolaas; Crowl, Todd Events such as volcanic eruptions may act as disturbance agents modifying the landscape spatial diversity and increasing environmental instability. On June 4, 2011 the Puyehue-Cordon Caulle volcanic complex located on Chile (2236 m.a.s.l., 40° 02' 24" S- 70° 14' 26" W) experience a rift zone eruption ejecting during the first day 950 million metric tons into the atmosphere. Due to the westerly winds predominance, ash fell differentially upon 24 million ha of Patagonia Argentinean, been thicker deposits accumulated towards the West. In order to analyze changes on stream fish assemblages we studied seven streams 8, 19 and 30 months after the eruption along the ash deposition gradient, and compare those data to pre eruption ones. Habitat features and structure of the benthic macroinvertebrate food base of fish was studied. After the eruption, substantial environmental changes were observed in association with the large amount of ash fallout. In western sites, habitat loss due to ash accumulation, changes in the riparian zone and morphology of the main channels were observed. Turbidity was the water quality variable which reflected the most changes throughout time, with NTU values decreasing sharply from West to East sites. In west sites, increased Chironomid densities were recorded 8 months after the initial eruption as well as low EPT index values. These relationships were reversed in the less affected streams farther away from the volcano. Fish assemblages were greatly influenced both by habitat and macroinvertebrate changes. The eruption brought about an initial sharp decline in fish densities and the almost total loss of young of the year in the most western streams affecting recruitment. This effect diminished rapidly with distance from the emission center. Thirty months after the eruption, environmental changes are still occurring as a consequence of basin wide ash remobilization and transport. Full Text Available Tulisan ini menyajikan data dan informasi tentang present status perikanan demersal di Laut Jawa, dan tingkat pemanfaatan sumber daya ikan di sub area Laut Jawa yang tidak merata. Data yang dianalisis merupakan sebagian hasil survei Balai Riset Perikanan Laut di Pelabuhan Perikanan Pantai Tegal pada tahun 2010 dan pada periode tahun sebelumnya. Eksploitasi sumber daya ikan demersal di perairan Laut Jawa sudah berlangsung sejak lama dan mencapai puncaknya pada sekitar tahun 1970-an di mana trawl dioperasikan secara intensif terutama di sepanjang pantai utara Jawa. Tingginya tekanan penangkapan di perairan pantai sampai kedalaman 40-an m telah menyebabkan menurunnya kelimpahan sumber daya, sebagaimana tampak pada hasil tangkapan cantrang kecil dan jaring arad yang dioperasikan secara harian. Kelimpahan dan ukuran individu ikan demersal di kawasan yang lebih dalam tampak cukup besar sebagaimana tercermin dari hasil tangkapan cantrang besar yang dioperasikan lebih lama. Dari fenomena tersebut dapat diduga bahwa sumber daya ikan demersal di perairan pantai sudah mengalami tangkap lebih (overfishing yang mengarah kepada penurunan stok atau bahkan depleted. Kegiatan penangkapan ikan di perairan yang lebih dalam di mana tekanan penangkapan relatif lebih rendah tampak memberikan keuntungan. Based on data analysis and information collected, this paper describes the present status of demersal fisheries in the Java Sea and the uneven level of exploitation of the fish resources in the Java Sea sub areas. Data analyzed provide part of research results carried out by the Research Institute for Marine Fisheries. Data were obtained from a number of surveis carried out in Tegal landing place in 2010 and from the previous years. Demersal resources in the Java Sea have been exploited for years, where high fishing intensity occurred in the north coast of Java. High fishing pressure in the coastal waters lead to the decreasing fish resources abundance, as Madin, John; Chong, V. C.; Basri, Badrulnizam A study was conducted at a fish culture farm in the Jaha River estuary, Malaysia, to examine the structure and development of macrofouling assemblages on floating net-cages. The study was conducted during the dry (August-October 2001) and wet (December-February 2002) seasons. Biofouling on 1.6 cm mesh net panels (size 0.2 m × 2 m) suspended inside (P, T) and outside (O) experimental net-cages was monitored every week until net openings were completely occluded by macrofouling organisms (8 wk and 12 wk for dry and wet seasons respectively). Seven species (6 phyla) of sessile organisms and 23 species (3 phyla) of non-sessile associates were recorded. Macro-colonization of net panels began with the hydroid Plumularia sp. irrespective of season and treatment (P, T, and O), while other species only appeared after 1 or 2 weeks of immersion. Inside net-cages where water flow was slow (mean macroalgae ( Polysiphonia sp.), anthozoans (unidentified anemone), barnacles ( Balanus amphitrite), amphipods ( Gammaropsis sp. & Photis sp.), and tanaids ( Leptognathia sp.) were dominant on the net panels during the dry season. In the wet season, hydroid ( Plumularia sp.), mussel ( Xenostrobus mangle), and nematode abundance were however significant. With stronger water flow (mean ≈ 20 cm s -1) as occurring outside the net-cages, macrofouling assemblages for both seasons comprised mainly Plumularia sp. and Gammaropsis sp. The macrofouling assemblage showed a clear succession of species that occupied different layers of the net panels. The study shows that while organic enrichment and retarded water flow together enhance the development of macrofouling assemblages, salinity, depth, substrate (net) area and species competition specifically influence community structure, colonization, and depth distribution of the macrofouling organisms. Baldigo, Barry P.; Ernst, Anne G.; Warren, Dana R.; Miller, Sarah J. Natural-channel-design (NCD) restorations were recently implemented within large segments of five first- and second-order streams in the Catskill Mountains of New York in an attempt to increase channel stability, reduce bed and bank erosion, and sustain water quality. In conjunction with these efforts, 54 fish and habitat surveys were done from 1999 to 2007 at six restored reaches and five stable control reaches to evaluate the effects of NCD restoration on fish assemblages, habitat, and bank stability. A before–after–control–impact study design and two-factor analysis of variance were used to quantify the net changes in habitat and fish population and community indices at treatment reaches relative to those at unaltered control reaches. The density and biomass of fish communities were often dominated by one or two small prey species and no or few predator species before restoration and by one or more trout (Salmonidae) species after restoration. Significant increases in community richness (30%), diversity (40%), species or biomass equitability (32%), and total biomass (up to 52%) in at least four of the six restored reaches demonstrate that NCD restorations can improve the health and sustainability of fish communities in geomorphically unstable Catskill Mountain streams over the short to marginally long term. Bank stability, stream habitat, and trout habitat suitability indices (HSIs) generally improved significantly at the restored reaches, but key habitat features and trout HSIs did not change or decreased at two of them. Fish communities and trout populations at these two reaches were not positively affected by NCD restorations. Though NCD restorations often had a positive effect on habitat and fish communities, our results show that the initial habitat conditions limit the relative improvements than can be achieved, habitat quality and stability do not necessarily respond in unison, and biotic and abiotic responses cannot always be generalized. Full Text Available The hydrological connectivity between the salt marsh and the sea was partially restored in a Mediterranean wetland containing isolated ponds resulting from former salt extraction and aquaculture activities. A preliminary assessment provided evidence that ponds farther from the sea hosted very large numbers of the endangered Spanish toothcarp, Aphanius iberus, suggesting that individuals had been trapped and consequently reach unnaturally high densities. In order to achieve both habitat rehabilitation and toothcarp conservation, efforts were made to create a gradient of hydrologically connected areas, including isolated fish reservoirs, semi-isolated, and connected salt marsh-sea areas that could allow migratory movements of fish and provide some protection for A. iberus. The fish community was monitored prior to, and for three years after rehabilitation. Results showed an increase in the number of fish species within semi-isolated areas (Zone A, whereas areas adjacent to the sea (Zone B increased the number of marine species and decreased that of estuarine species (ES. Yet overall differences in fish assemblages were much higher between zones than among study years. Generalized linear models (GLMs evidenced that distance to the sea was the most important variable explaining the local diversity of the fish community after restoration, with occasional influence of other factors such as temperature, and depth. The abundance of A. iberus was consistently higher in semi-isolated areas at greater distances from the sea, but a decline occurred in both zones and in isolated reservoir ponds after restoration efforts, which may be attributable to interannual differences in recruitment success and, to a lesser extent, to dispersal into adjacent habitats. A negative effect of restoration works on fish population cannot be excluded, but the final outcome of the intervention likely needs a longer period. Martina Di Iulio Ilarri Full Text Available The effects of tourist visitation and food provisioning on fish assemblages were assessed by visual censuses (stationary technique carried out in a tropical reef in Northeastern Brazil. Comparisons of species abundance, richness, equitability, and trophic structure in the presence (PT and absence (AT of tourists suggest that tourist visitation and supplementary food influenced the structure of the fish assemblage, as follows: (a diversity, equitability and species richness were significantly higher on the AT period, while the abundance of a particular species was significantly higher during PT; (b trophic structure differed between the AT and PT periods, omnivores being more abundant during the latter period, while mobile invertivores, piscivores, roving herbivores and territorial herbivores were significantly more abundant on AT. Reef tourism is increasingly being regarded as an alternative to generate income for human coastal communities in the tropics. Therefore, closer examination of the consequences of the various components of this activity to reef system is a necessary step to assist conservation and management initiatives. Edson Fontes Oliveira Full Text Available Ecomorphological patterns of the fish assemblage from the upper Paraná River floodplain, Brazil, were described and evaluated according to trophic (guilds, spatial (habitats and phylogenetic (taxonomic distances structures. The samples were obtained through the Long Term Research Project (LTER-CNPq/UEM/NUPELIA in August and October 2001. Thirty-five species were analyzed from thirty-one morphological variables. Strong significant correlations (Mantel test between morphology and trophic guilds and between morphology and taxonomy were found, while morphology and habitat revealed a weak correlation. However, the partial Mantel test showed that the correlations between morphology and trophic guilds persist even when the effect of taxonomy is discounted. The ecomorphological pattern shown by the Principal Component Analysis separated species according to locomotion structures used in feeding. At one extreme there are the piscivores and insectivores that exploit lentic habitats and have compressed bodies and well developed anal fins, while at the other there are detritivores and invertivores that exploit lotic and semi-lotic habitats and have depressed bodies and well developed pectoral, pelvic and caudal fins. Canonical Discriminant Analysis using ecomorphological variables successfully predicted 94.5% of the trophic guild ecomorphotypes, but only 57.1% of the habitat ecomorphotypes. These data indicate that the fish assemblage of the upper Paraná River floodplain is structured ecomorphologically mainly according to trophic structure rather than habitat. Stagličić, Nika; Šegvić-Bubić, Tanja; Ugarković, Pero; Talijančić, Igor; Žužul, Iva; Tičina, Vjekoslav; Grubišić, Leon The ecological effects of tuna fish farms are largely undocumented. This study confirmed their high capacity to attract surrounding wild fish. The aggregation effect persisted year round, without detectable seasonal differences. Farm impact was restricted to close proximity of the sea cages, and was more prominent over the bottom than in the water column strata. Tuna fish farms proved to be high energy trophic resources, as indicated by the enhanced fitness status of two focal species, bogue and seabream. Under abundant food supply, seabream appear to allocate the majority of energy reserves to gonad development. Farm associated bogue had greater parasite loads, with no detrimental effect on fitness status. Overall, tuna fish farms can be regarded as population sources for aggregated wild fish, and under the no fishing conditions within the leasehold areas, can serve as functional marine protected areas. Copyright © 2017 Elsevier Ltd. All rights reserved. Full Text Available Artificial reefs were deployed within the Golfe-Juan marine protected area (Alpes-Maritimes coast, France, Northwestern Mediterranean created in 1981. This no-take area is fully protected since its establishment, except in 2004 when some anthropic activities were, exceptionally, authorized. Moreover, no park rangers to prevent poaching since 2002 occur. In order to carry out a long term monitoring of the artificial reef fish assemblages, underwater visual censuses (UVC were carried out in 1988, 1998 and 2008, according to a traditional standardized visual census method that taken into account all fish species. The complexification of some large reefs built with wide voide spaces called Bonna reefs appear to be a good solution to increase species richness and density. Species richness and density of the fish assemblages showed significant increase between 1988 and 1998. However the fast increasing was stopped from 1998 and 2008 probably due to a lack of law enforcement and poaching. Despite artificial reefs were deployed in MPA since at least 20 years, they did not show a real positive impact on fish assemblages. These results could be explained (i by a lack of law enforcement patrol within the protected areas during the last decade, and (ii by the one-year opening to fishing activities within MPA. The real effectiveness of the artificial reefs in sustaining fish assemblages is discussed and the necessity of a regular and efficient control by park rangers is highlighted.Recifes artificiais foram implantados na área protegida Golfe-Juan (costa dos Alpes-Maritimes, Noroeste do Mediterraneo criada em 1981. Esta área NTZ (Area de Restrição da Pesca é inteiramente protegida, desde seu estabelecimento, exceto em 2004, quando algumas atividades antropicas foram excepcionalmente autorizadas. Além disso, desde 2002, não houve nenhuma patrulha florestal para impedir a caça e pesca ilegais. . A fim realizar um monitoramento a longo prazo das assembl Nielsen, J. Rasmus; Ulrich, Clara; Hegland, Troels J. The present report is an EU-FP7-SOCIOEC Report giving an overview and critical evaluation of the current management measures implemented for the North Sea mixed demersal fisheries and the fish stocks involved in this. Also, this involves review and critical evaluation of the scientific advice... Full Text Available This work aims to undertake a preliminary characterization of winter fish assemblages in the salt marsh areas of Guadiana lower estuary (South-East Portugal and discusses the potential risks of habitat dominance by a non-indigenous species (NIS. To this effect, six field campaigns were carried out in four sampling sites during winter season targeting the collection of fish species. A total of 48 samples were collected. Individuals from seven different taxa (marine and estuarine were collected, although the assemblage was dominated by two estuarine species—the native Pomatoschistus sp. (goby and the NIS Fundulus heteroclitus (mummichog. Goby was the most abundant taxa in the majority of salt marsh habitats, except for one specific, marsh pool, where extreme environmental conditions were registered, namely high temperature and salinity. Such conditions may have boosted the intrusion of mummichog in this area. This species is well adapted to a wide range of abiotic factors enabling them to colonize habitats where no predators inhabit. Impacts of mummichog introduction in the Guadiana salt marsh area are still unpredictable since this is the first time they have been recorded in such high density. Nevertheless, in scenarios of increased anthropogenic pressure and, consequently, habitat degradation, there is a potential risk of mummichog spreading to other habitats and therefore competing for space and food resources with native species. Díaz-Pérez, Leopoldo; Rodríguez-Zaragoza, Fabián Alejandro; Ortiz, Marco; Cupul-Magaña, Amílcar Leví; Carriquiry, Jose D; Ríos-Jara, Eduardo; Rodríguez-Troncoso, Alma Paola; García-Rivas, María Del Carmen This study evaluated the relationship between the indices known as the Reef Health Index (RHI) and two-dimensional Coral Health Index (2D-CHI) and different representative metrics of biological, ecological and functional diversity of fish and corals in 101 reef sites located across seven zones in the western Caribbean Sea. Species richness and average taxonomic distinctness were used to asses biological estimation; while ecological diversity was evaluated with the indices of Shannon diversity and Pielou´s evenness, as well as by taxonomic diversity and distinctness. Functional diversity considered the number of functional groups, the Shannon diversity and the functional Pielou´s evenness. According to the RHI, 57.15% of the zones were classified as presenting a "poor" health grade, while 42.85% were in "critical" grade. Based on the 2D-CHI, 28.5% of the zones were in "degraded" condition and 71.5% were "very degraded". Differences in fish and coral diversity among sites and zones were demonstrated using permutational ANOVAs. Differences between the two health indices (RHI and 2D-CHI) and some indices of biological, ecological and functional diversity of fish and corals were observed; however, only the RHI showed a correlation between the health grades and the species and functional group richness of fish at the scale of sites, and with the species and functional group richness and Shannon diversity of the fish assemblages at the scale of zones. None of the health indices were related to the metrics analyzed for the coral diversity. In general, our study suggests that the estimation of health indices should be complemented with classic community indices, or should at least include diversity indices of fish and corals, in order to improve the accuracy of the estimated health status of coral reefs in the western Caribbean Sea. Winemiller, K.O.; Lopez-Fernandez, H.; Taphorn, D.C.; Nico, L.G.; Duque, A.B. Aim: The aim of this study was to determine whether the Casiquiare River functions as a free dispersal corridor or as a partial barrier (i.e. filter) for the interchange of fish species of the Orinoco and Negro/Amazon basins using species assemblage patterns according to geographical location and environmental features. Location: The Casiquiare, Upper Orinoco and Upper Negro rivers in southern Venezuela, South America. Methods: Our study was based on an analysis of species presence/absence data and environmental information (11 habitat characteristics) collected by the authors and colleagues between the years 1984 and 1999. The data set consisted of 269 sampled sites and 452 fish species (> 50,000 specimens). A wide range of habitat types was included in the samples, and the collection sites were located at various points along the entire length of the Casiquiare main channel, at multiple sites on its tributary streams, as well as at various nearby sites outside the Casiquiare drainage, within the Upper Orinoco and Upper Rio Negro river systems. Most specimens and field data used in this analysis are archived in the Museo de Ciencias Naturales in Guanare, Venezuela. We performed canonical correspondence analysis (CCA) based on species presence/absence using two versions of the data set: one that eliminated sites having < 5 species and species occurring at < 5 sites; and another that eliminated sites having < 10 species and species occurring at < 10 sites. Cluster analysis was performed on sites based on species assemblage similarity, and a separate analysis was performed on species based on CCA loadings. Results: The CCA results for the two versions of the data set were qualitatively the same. The dominant environmental axis contrasted assemblages and sites associated with blackwater vs. clearwater conditions. Longitudinal position on the Casiquiare River was correlated (r2 = 0.33) with CCA axis-1 scores, reflecting clearwater conditions nearer to its origin Akin, S.; Buhan, E.; Winemiller, K. O.; Yilmaz, H. Spatial and temporal variation in fish assemblage structure of Koycegiz Lagoon-Estuarine System (KLES), located on the northwestern Turkish coast of Mediterranean, was investigated along an estuarine gradient where salinity ranged from 5 in upper reaches to 40 in lower reaches during October 1993-September 1994. Throughout the study, 42 species, consisting of marine (25), marine-estuarine-dependent (12), freshwater (3), catadromous (1), and estuarine resident (1) forms, were collected in trammel nets. Although species richness of marine species was greater than that of other groups, numerical contribution by marine species to the total catch was only 16%. Tilapia spp., the most abundant species mostly during summer and early spring at upper reaches, contributed 17% of the total samples. Among the seven species of Mugilidae, which contributed 42% of the total catch, Mugil cephalus, Liza aurata, and Liza salines contributed 10, 13, and 10% of the total catch, respectively. Consistent with findings from other studies, species richness and abundance were highest during late spring and summer and the lowest during winter and early spring. Samples from sites at or near the sea had more marine species. Samples from upper reaches had more freshwater and marine-estuarine-dependent species. Canonical correspondence analysis (CCA) indicated that salinity and turbidity were the most important environmental parameters affecting fishes. Sites near the sea were associated with high salinity and low turbidity, and sites in upper reaches had low salinity and high turbidity. Thus, the pattern observed in fish assemblage structure appears to be strongly influenced by species' responses to dominant salinity and turbidity gradients. Kennen, J.G.; Chang, M.; Tracy, B.H. We evaluated a comprehensive set of natural and land-use attributes that represent the major facets of urban development at fish monitoring sites in the rapidly growing Raleigh-Durham, North Carolina metropolitan area. We used principal component and correlation analysis to obtain a nonredundant subset of variables that extracted most variation in the complete set. With this subset of variables, we assessed the effect of urban growth on fish assemblage structure. We evaluated variation in fish assemblage structure with nonmetric multidimensional scaling (NMDS). We used correlation analysis to identify the most important environmental and landscape variables associated with significant NMDS axes. The second NMDS axis is related to many indices of land-use/land-cover change and habitat. Significant correlations with proportion of largest forest patch to total patch size (r = -0.460, P < 0.01), diversity of patch types (r = 0.554, P < 0.001), and population density (r = 0.385, P < 0.05) helped identify NMDS axis 2 as a disturbance gradient. Positive and negative correlations between the abundance of redbreast sunfish Lepomis auritus and bluehead chub Nocomis leptocephalus, respectively, and NMDS axis 2 also were evident. The North Carolina index of biotic integrity and many of its component metrics were highly correlated with urbanization. These results indicate that aquatic ecosystem integrity would be optimized by a comprehensive integrated management strategy that includes the preservation of landscape function by maximizing the conservation of contiguous tracts of forested lands and vegetative cover in watersheds. ?? 2005 by the American Fisheries Society. Full Text Available This study examined diversity and habitat characteristics for bycatch assemblages in two different types of fishing (drifting fish aggregating devices sets and sets made on school of tunas in the eastern Pacific Ocean (20°S–30°N and 70°–150°W between 2005 and 2011 using biodiversity metrics and Generalized Additive Models. Bycatch information was based on data collected by onboard observers covering more than 80% of the purse seine fishing trips. Our results suggest that diversity and habitat characteristics of the bycatch assemblages differ depending of the fishing mode. Thus, diversity was mostly explained by area and set type; being higher in fish aggregating devices (FAD sets than School sets. Concretely, diversity seems to be directly related with the equatorial upwelling and the front system in FAD sets and with the Costa Rica Dome and the coastal upwelling of Panama induced by wind jets in School sets. Among environmental variables, temperature and chlorophyll were the most important predictors to describe the diversity of the bycatch assemblages. This work has investigated multiple indicators related to the bycatch assemblages and their habitat, which could be helpful for the development of an Ecosystem Approach to Fishery Management (EAFM. Chen, Tsen-Chien; Ho, Cheng-Tze; Jan, Rong-Quen Background Recreational scuba diving is a popular activity of the coral reef tourism industry. In practice, local diving centers recommend interesting sites to help visiting divers make their plans. Fish are among the major attractions, but they need to be listed with care because the temporal occurrence of a fish species is difficult to predict. To address this issue, we propose methods to categorize each fish species based on its long-term occurrence and likelihood of being seen. Methods We... Biomass and fishing potential yield of demersal resources from the outer shelf and upper slope of southern Brazil Biomasa y rendimiento potencial pesquero de recursos demersales de la plataforma externa y talud superior del sur de Brasil Full Text Available The relative abundance and fishing potential of the commercially valuable fishes and cephalopods with marketable size was assessed using two seasonal bottom trawl surveys performed in 2001 and 2002 on the outer shelf and upper slope (100-600 m depth off the coast of southern Brazil. These surveys were part of REVIZEE, a national program designed to assess the fishery potential within the Economic Exclusive Zone. Of the 228 fish and cephalopod species caught during the surveys, only 27 species and genera were considered to be of commercial interest. Commercial-sized individuals of these species made up 52.3% of the total catch. The total biomass was estimated to be 167,193 ton (± 22% and 165,460 ton (± 25% in the winter-spring and summer-autumn surveys, respectively. The most abundant species were the Argentine short-fin squid Illex argentinas, a species with highly variable recruitment, followed by the Argentine hake Merluccius hubbsi, the gulf-hake Urophycis mystacea, and the monkfish Lophius gastrophysus. The latter three were intensively fished prior to the surveys, as well as the beardfish Polymixia lowei and silvery John dory Zenopsis conchifera, both relatively abundant but with a very low market value. The potential yield of the demersal fish species, not considering Illex argentinus, estimated with the Gulland equation for a mean natural mortality of M = 0.31, was 20,460 ton. When considering only Merluccius hubbsi, Urophycis mystacea, and Lophius gastrophysus, the potential yield decreased to 6,625 ton. The surveys showed that the fishery potential of the outer shelf and upper slope was substantially lower than that of the inner shelf. Therefore, this environment should be carefully monitored to avoid overfishing and fast depletion.Se evaluó la abundancia relativa y el potencial pesquero de peces y cefalópodos de especies y tamaños de valor comercial en dos muéstreos estacionales con redes de arrastre de fondo realizados en los a Full Text Available The main goal of the study was to obtain field data to build a baseline of fish assemblage composition that can be used comparatively for future analyses of the impact of human actions in the region. A basic network of 68 sampling stations was defined for the entire region (4 050 km2. Fish assemblage species and size composition was estimated using visual census methods at three different spatial scales: a entire region, b inside the main reef area and c along a human impact coastal gradient. Multivariate numerical analyses revealed habitat type as the main factor inducing spatial variability of fish community composition, while the level of human impact appears to play the main role in fish assemblage composition changes along the coast. A trend of decreasing fish size toward the east supports the theory of more severe human impact due to overfishing and higher urban pollution in that direction. This is the first detailed study along the northwest coast of Cuba that focuses on fish community structure and the natural and human-induced variations at different spatial scales for the entire NW shelf. This research also provides input for a more comprehensive understanding of coastal marine fish communities’ status in the Gulf of Mexico basin. Rev. Biol. Trop. 57 (3: 721-740. Epub 2009 September 30.Se obtuvieron datos de campo para una línea base de la composición de la ictiofauna que pueda ser usada comparativamente para el análisis de impactos humanos futuros en la región. Se estableció una red básica de 68 estaciones de muestreo para la región completa (4 050 km2. La composición por especies y por tallas de la ictiofauna fue estimada utilizando métodos de censo visual en tres escalas espaciales diferentes: a La región completa, b dentro del área principal de arrecifes y c a lo largo de un gradiente costero de impacto humano. El tipo de hábitat es el factor principal que induce la variación espacial en la composición de la Full Text Available In the Ebro Delta coastal lagoons, one of the main anthropogenic pressures is the artificial freshwater input. Each coastal lagoon has different water management schemes causing profound changes in its physicochemical characteristics. The main objective of this water management is to favour some bird species with interest either for conservation or hunting activities. The present study assesses the influence of hydrological alteration on the fish assemblages of three coastal lagoons in the Ebro Delta. The small-bodied fish fauna was mainly composed of five families: Gobiidae, Poecilidae, Cyprinodontidae, Atherinidae and Mugilidae. Salinity was found to be the main factor structuring fish community in the lagoons. The dominant species was the common goby (Pomatochistus microps when the lagoons reached higher salinity values, whereas the invasive eastern mosquitofish (Gambusia holbrooki dominated during the period of higher freshwater inputs. The juveniles of the family Mugilidae showed low catch per unit effort, especially during the period of lower salinity. This same pattern was found for the endangered Spanish toothcarp (Aphanius iberus. Overall, introduced species were favoured by low salinity, which highlights the importance of changing the present water management by reducing the freshwater inputs in order to maintain suitable levels of salinity to favour native species that are important for both commercial and conservation purposes. Aguado-Giménez, Felipe; Eguía-Martínez, Sergio; Cerezo-Valverde, Jesús; García-García, Benjamín Ichthyophagous birds aggregate at cage fish farms attracted by caged and associated wild fish. Spatio-temporal variability of such birds was studied for a year through seasonal visual counts at eight farms in the western Mediterranean. Correlation with farm and location descriptors was assessed. Considerable spatio-temporal variability in fish-eating bird density and assemblage structure was observed among farms and seasons. Bird density increased from autumn to winter, with the great cormorant being the most abundant species, also accounting largely for differences among farms. Grey heron and little egret were also numerous at certain farms during the coldest seasons. Cattle egret was only observed at one farm. No shags were observed during winter. During spring and summer, bird density decreased markedly and only shags and little egrets were observed at only a few farms. Season and distance from farms to bird breeding/wintering grounds helped to explain some of the spatio-temporal variability. Copyright © 2018 Elsevier Ltd. All rights reserved. Full Text Available This is the first study to explore fish community structure and its relations to habitat and topographic complexity in the shallow coastal waters of the Cyclades Archipelago, North-eastern Mediterranean Sea. In situ visual surveys were carried out at 233 sampling sites in 26 islands of the Cyclades Archipelago. Fish community parameters and biomass were estimated across seven substrate types: sand, seagrass, vertical walls, boulders, horizontal/subhorizontal continuous rock, rocky substrate with patches of sand, and rocky substrate with patches of sand and Posidonia oceanica. Topographic complexity and percentage of algal cover were estimated on hard substrate. Substrate type was found to be a determining factor affecting the structure and composition of fish assemblages. Species number, abundance and biomass were significantly lower in sandy areas and always higher on hard substrates, with seagrass habitats presenting intermediate values. Topographic complexity in rocky bottoms did not seem to affect species richness, density or biomass. This study provides a baseline for future evaluation of changes produced by potential management actions such as the creation of marine protected areas in the study region. Cheek, Brandon D.; Grabowski, Timothy B.; Bean, Preston T.; Groeschel, Jillian R.; Magnelia, Stephan J. Habitat heterogeneity at multiple scales is a major factor affecting fish assemblage structure. However, assessments that examine these relationships at multiple scales concurrently are lacking. The lack of assessments at these scales is a critical gap in understanding as conservation and restoration efforts typically work at these levels.A combination of low-cost side-scan sonar surveys, aerial imagery using an unmanned aerial vehicle, and fish collections were used to evaluate the relationship between physicochemical and landscape variables at various spatial scales (e.g. micro-mesohabitat, mesohabitat, channel unit, stream reach) and stream–fish assemblage structure and habitat associations in the South Llano River, a spring-fed second-order stream on the Edwards Plateau in central Texas during 2012–2013.Low-cost side-scan sonar surveys have not typically been used to generate data for riverscape assessments of assemblage structure, thus the secondary objective was to assess the efficacy of this approach.The finest spatial scale (micro-mesohabitat) and the intermediate scale (channel unit) had the greatest explanatory power for variation in fish assemblage structure.Many of the fish endemic to the Edwards Plateau showed similar associations with physicochemical and landscape variables suggesting that conservation and restoration actions targeting a single endemic species may provide benefits to a large proportion of the endemic species in this system.Low-cost side-scan sonar proved to be a cost-effective means of acquiring information on the habitat availability of the entire river length and allowed the assessment of how a full suite of riverscape-level variables influenced local fish assemblage structure. Full Text Available The aim of this work was to determine the composition of the fish assemblage of Passa Cinco stream and verify changes in their structure on the altitudinal gradient. Six samples were performed at five different sites in Passa Cinco stream (from the headwater, at order two, to its mouth, at order six, using an electric fishery equipment and gill nets in May, July, September and November of 2005 and January and March of 2006. The indices of Shannon's diversity, Pielou's evenness and Margalef's richness were quantified separately considering the different fishery equipment (nets versus electric fishery equipment. An ANOVA was used to compare samples collected in relation to values of abundance, diversity, evenness and richness. The representativeness of the species was summarised by their average values of abundance and weight. We captured 5082 individuals distributed into 61 species. We observed a trend of increasing diversity, richness and evenness of species from site 1 to 3, with further decrease in sites 4 and 5. The values found for habitat diversity also followed this pattern. Significant differences were found for all three indices considering the electric fishery samples. For individuals caught with nets, only the richness index showed a significant difference. Characidium aff. zebra was an important species in the headwater and transition sites and Hypostomus strigaticeps in middle-lower course sites. Despite the small extension of the Passa Cinco stream, environments structurally well defined were evidenced by the species distribution and assemblage composition along the gradient. W. M. Domingues Full Text Available In this study, patterns of spatial synchrony in population fluctuations (cross-correlation of an endemic fish assemblage of a Neotropical reservoir (Segredo Reservoir, Iguaçu River, Paraná State, Brazil were reported. First, the level of population synchrony for 20 species was estimated. Second, population synchrony was correlated, using the Mantel test, with geographical distances among sites (n = 11 and also environmental synchrony (temperature. Nine species presented significant correlations between spatial synchrony and geographic distances (Astyanax sp. b, Astyanax sp. c, Pimelodus sp., Hoplias malabaricus, Crenicichla iguassuensis, Hypostomus derbyi, Hypostomus myersi, Rhamdia branneri, and R. voulezi. Considering the ecology of the species and the significant relationship between population and environmental synchronies, it seems that environmental stochasticity is the most plausible hypothesis in explaining the observed synchrony patterns. Vokoun, Jason C.; Rabeni, Charles F. Fish assemblages were systematically sampled along the transition from channelized to unchannelized reaches in seven streams in northern Missouri, USA. Streams ranged in size from 4th to 8th order and were located in the Central Dissected Till Plains including the Grand, Chariton, Salt, and Fabius watersheds. Maximum species richness was reached 3-5 km downstream from the end of channelization. A limited core group of 10 species was present at most of the sites (channelized and unchannelized locations), and a diverse group of 45 species was present at relatively few sites (rarely channelized locations). The core group consisted largely of tolerant, omnivorous species and contained no top carnivores. The 45-species diverse group included a greater proportion of intolerant, benthic invertivorous, lithophilous, and carnivorous species. The effect of channelization extended well into unchannelized reaches and should be considered by conservation planners. Full Text Available We examined the recovery of a fish assemblage following the catastrophic spill of highly alkaline (pH~13 red sludge into a lowland river (i to characterize taxonomic and trait based colonization of fishes in the river in the first three years of the recovery, and (ii to determine which structural and trait based variables best predicted colonization. Species richness showed comparable values to pre-disturbance state less than one year after the spill. We found only moderate changes in the dominance of the most abundant species between pre- and post-disturbance periods, and consistent changes in the relative abundance of some rare species during the post-disturbance period. Frequency of occurrence (% of the fishes in the watershed, and their relative abundance (% proved to be the most important predictor variables in colonization, whereas trait based variables had a less important role. Our study about one of the largest scale and most serious documented fish kill shows that both taxonomic and trait based structure of fish assemblages can regenerate remarkable fast in a modified river and also shows that unfortunate chemical spills provide insights into the assembly of stream fish assemblages. Whitfield, Alan K; Weerts, Steven P; Weyl, Olaf L F The Holocene evolution of eight South African coastal lakes and lagoons is examined and related to changes in fish composition over that period. Historical and current connectivity with riverine and marine environments are the primary determinants of present-day fish assemblages in these systems. A small and remarkably consistent group of relict estuarine species have persisted in these coastal lakes and lagoons. The loss or reduction of connectivity with the sea has impacted on the diversity of marine fishes in all eight study systems, with no marine fishes occurring in those water bodies where connectivity has been completely broken (e.g. Sibaya, Groenvlei). In systems that have retained tenuous linkages with the sea (e.g., Verlorenvlei, Wilderness lakes), elements of the marine fish assemblage have persisted, especially the presence of facultative catadromous species. Freshwater fish diversity in coastal lakes and lagoons is a function of historical and present biogeography and salinity. From a freshwater biogeography perspective, the inflowing rivers of the four temperate systems reviewed here contain three or fewer native freshwater fishes, while the subtropical lakes that are fed by river systems contain up to 40 freshwater fish species. Thus, the significantly higher fish species diversity in subtropical versus temperate coastal lakes and lagoons comes as no surprise. Fish species diversity has been increased further in some systems (e.g., Groenvlei) by alien fish introductions. However, the impacts of fish introductions and translocations have not been studied in the coastal lakes and lagoons of South Africa. In these closed systems, it is probable that predation impacts on small estuarine fishes are significant. The recent alien fish introductions is an example of the growing threats to these systems during the Anthropocene, a period when human activities have had significant negative impacts and show potential to match the changes recorded during the Richard M. Starr Full Text Available The deepwater faunas of oceanic islands and seamounts of the Eastern Tropical Pacific are poorly known. From 11-22 September 2009 we conducted an exploration of the deepwater areas of the Isla del Coco Marine Conservation Area, Costa Rica and a nearby seamount using a manned submersible. The goal of the exploration was to characterize the habitats and biota, and conduct quantitative surveys of the deepwater portions of Isla del Coco National Park and Las Gemelas Seamount, located about 50km southwest of Isla del Coco. We completed a total of 22 submersible dives, spanning more than 80hr underwater, and collected a total of 36hr of video. We surveyed habitats from 50-402m and observed more than 45 species of fishes, some of which have not yet been described and are likely new to science. The diversity of fish species in deep water at Isla del Coco National Park was lower than the diversity of fishes in shallow water, and eight species groups accounted for more than 95% of the total fish biomass. The combined density of all fish species was higher at Las Gemelas Seamount (253 fishes/100m² than at Isla del Coco National Park (138 fishes/100m². The combined density of fishes in habitats comprised primarily of bedrock or large boulders outcrops was more than three times as high at Las Gemelas Seamount as it was at Isla del Coco National Park. This discrepancy was caused by the extremely high concentration of Anthiinae fishes in rocky habitats at Las Gemelas Seamount. Densities of fishes in the other habitats were similar between the two sites. Similarly, when estimates of fish density were plotted by slope categories the density was much greater on steep slopes, which were usually comprised of rock habitats. Also, the density of fishes was greatest on high rugosity habitats. Results of these submersible surveys indicate that seamounts in the tropical eastern Pacific Ocean may be an important source of biodiversity and that more quantitative surveys Baldigo, Barry P.; Kulp, Matt A.; Schwartz, John S. The acidity of many streams in the Great Smoky Mountains National Park (GRSM) has increased significantly since pre-industrial (∼1850) times due to the effects of highly acidic atmospheric deposition in poorly buffered watersheds. Extensive stream-monitoring programs since 1993 have shown that fish and macroinvertebrate assemblages have been adversely affected in many streams across the GRSM. Matching chemistry and fishery information collected from 389 surveys performed at 52 stream sites over a 22-year period were assessed using logistic regression analysis to help inform the U.S. Environmental Protection Agency’s assessment of the environmental impacts of emissions of oxides of nitrogen (NOx) and sulfur (SOx). Numerous logistic equations and associated curves were derived that defined the relations between acid neutralizing capacity (ANC) or pH and different levels of community richness, density, and biomass; and density and biomass of brook trout, rainbow trout, and small prey (minnow) populations in streams of the GRSM. The equations and curves describe the status of fish assemblages in the GRSM under contemporary emission levels and deposition loads of nitrogen (N) and sulfur (S) and provide a means to estimate how newly proposed (and various alternative) target deposition loads, which strongly influence stream ANC, might affect key ecological indicators. Several examples using ANC, community richness, and brook trout density are presented to illustrate the steps needed to predict how future changes in stream chemistry (resulting from different target deposition loads of N and S) will affect the probabilities of observing specific levels of selected biological indicators in GRSM streams. The implications of this study to the regulation of NOx and SOx emissions, water quality, and fisheries management in streams of the GRSM are discussed, but also qualified by the fact that specific examples provided need to be further explored before recommendations Jeremiah G. Plass-Johnson Full Text Available The Spermonde Archipelago is a complex of ~70 mostly populated islands off Southwest Sulawesi, Indonesia, in the center of the Coral Triangle. The reefs in this area are exposed to a high level of anthropogenic disturbances. Previous studies have shown that variation in the benthos is strongly linked to water quality and distance from the mainland. However, little is known about the fish assemblages of the region and if their community structure also follows a relationship with benthic structure and distance from shore. In this study, we used eight islands of the archipelago, varying in distance from 1 to 55 km relative to the mainland, and 3 years of surveys, to describe benthic and fish assemblages and to examine the spatial and temporal influence of benthic composition on the structure of the fish assemblages. Cluster analysis indicated that distinct groups of fish were associated with distance, while few species were present across the entire range of sites. Relating fish communities to benthic composition using a multivariate generalized linear model confirmed that fish groups relate to structural complexity (rugosity or differing benthic groups; either algae, reef builders (coral and crustose coralline algae or invertebrates and rubble. From these relationships we can identify sets of fish species that may be lost given continued degradation of the Spermonde reefs. Lastly, the incorporation of water quality, benthic and fish indices indicates that local coral reefs responded positively after an acute disturbance in 2013 with increases in reef builders and fish diversity over relatively short (1 year time frames. This study contributes an important, missing component (fish community structure to the growing literature on the Spermonde Archipelago, a system that features environmental pressures common in the greater Southeast Asian region. Dec 22, 2008 ... Within a catchment, fish conservation may consider the full suite of species ... mental conditions, a river ecosystem may be transformed to the extent that a new ...... ent characteristics that should be considered functional units. Pratchett, M.S.; Hoey, A.S.; Wilson, S.K.; Messmer, V.; Graham, N.A.J. Coral reef ecosystems are increasingly subject to severe, large-scale disturbances caused by climate change (e.g., coral bleaching) and other more direct anthropogenic impacts. Many of these disturbances cause coral loss and corresponding changes in habitat structure, which has further important effects on abundance and diversity of coral reef fishes. Declines in the abundance and diversity of coral reef fishes are of considerable concern, given the potential loss of ecosystem function. This study explored the effects of coral loss, recorded in studies conducted throughout the world, on the diversity of fishes and also on individual responses of fishes within different functional groups. Extensive (>60%) coral loss almost invariably led to declines in fish diversity. Moreover, most fishes declined in abundance following acute disturbances that caused >10% declines in local coral cover. Response diversity, which is considered critical in maintaining ecosystem function and promoting resilience, was very low for corallivores, but was much higher for herbivores, omnivores and carnivores. Sustained and ongoing climate change thus poses a significant threat to coral reef ecosystems and diversity hotspots are no less susceptible to projected changes in diversity and function. Coral reef ecosystems are increasingly subject to severe, large-scale disturbances caused by climate change (e.g., coral bleaching) and other more direct anthropogenic impacts. Many of these disturbances cause coral loss and corresponding changes in habitat structure, which has further important effects on abundance and diversity of coral reef fishes. Declines in the abundance and diversity of coral reef fishes are of considerable concern, given the potential loss of ecosystem function. This study explored the effects of coral loss, recorded in studies conducted throughout the world, on the diversity of fishes and also on individual responses of fishes within different functional groups. Extensive (>60%) coral loss almost invariably led to declines in fish diversity. Moreover, most fishes declined in abundance following acute disturbances that caused >10% declines in local coral cover. Response diversity, which is considered critical in maintaining ecosystem function and promoting resilience, was very low for corallivores, but was much higher for herbivores, omnivores and carnivores. Sustained and ongoing climate change thus poses a significant threat to coral reef ecosystems and diversity hotspots are no less susceptible to projected changes in diversity and function. Li, Yalei; Liu, Qigen; Chen, Liping; Zhao, Liangjie; Wu, Hao; Chen, Liqiao; Hu, Zhongjun Two fishing methods including gillnetting and trawling to estimate attributes of fish assemblage were compared in Dianshan Lake from August 2009 to July 2010. Species composition differed significantly between the gears, with four significant contributors in gillnet catches and one in trawl catches. Trawling collected more proportions of benthic species by number and biomass than gillnetting. Size distribution was significantly influenced by fishing technique; gillnetting captured relatively less small-sized fishes and trawling captured less large-sized individuals. Trawling produced species richness closer to the one expected than gillnetting. On the whole, trawl catch was a quadratic polynomial function of gillnet catch and a significantly negative correlation was found between them, both of which varied as different polynomial functions of temperature. However, trawl and gillnet catches were significantly correlated only in one of five month groups. It is concluded that single-gear-based surveys can be misleading in assessments of attributes of fish assemblages, bottom trawling is a more effective gear for assessing fish diversity than benthic gillnetting, and using gillnet catches as an indicator of fish density depends on fishing season in the lake. Craig A Boys Full Text Available Fish screens can help prevent the entrainment or injury of fish at irrigation diversions, but only when designed appropriately. Design criteria cannot simply be transferred between sites or pump systems and need to be developed using an evidence-based approach with the needs of local species in mind. Laboratory testing is typically used to quantify fish responses at intake screens, but often limits the number of species that can studied and creates artificial conditions not directly applicable to screens in the wild. In this study a field-based approach was used to assess the appropriateness of different screen design attributes for the protection of a lowland river fish assemblage at an experimental irrigation pump. Direct netting of entrained fish was used along with sonar technology to quantify the probability of screen contact for a Murray-Darling Basin (Australia fish species. Two approach velocities (0.1 and 0.5 m.sec(-1 and different sizes of woven mesh (5, 10 and 20 mm were evaluated. Smaller fish (<150 mm in the assemblage were significantly more susceptible to entrainment and screen contact, especially at higher approach velocities. Mesh size appeared to have little impact on screen contact and entrainment, suggesting that approach velocity rather than mesh size is likely to be the primary consideration when developing screens. Until the effects of screen contacts on injury and survival of these species are better understood, it is recommended that approach velocities not exceed 0.1 m.sec(-1 when the desire is to protect the largest range of species and size classes for lowland river fish assemblages in the Murray-Darling Basin. The field method tested proved to be a useful approach that could compliment laboratory studies to refine fish screen design and facilitate field validation. Hu, Zhongjun; Wang, Siqing; Wu, Hao; Chen, Qingjiang; Ruan, Renliang; Chen, Liqiao; Liu, Qigen Using multi-mesh gillnets and trawls, the fish communities in Dianshan Lake at 6 stations from Oct. 2009 to Jul. 2010 were investigated seasonally to reveal the biodiversity and its spatial and temporal distribution patterns. The long-term changes in their structural characteristics were then analyzed to identify the main influencing factors and several measures for lake restoration were put forward. Thirty six species, belonging to 9 family and 30 genera, were collected, amongst which, the order Cypriniformes accounted for 61.1% of the total species number. In terms of importance value, Cypriniformes was the predominant group, Coilia nasus the dominant species, while Cyprinus carpio and Rhinogobius giurinus were the subdominant taxa. The community types did not differ among stations, but between seasons. There were no significant differences between seasons and among stations in species diversity, but richness differed both spatially and seasonally. Along with the process of eutrophication and the drastic reduction of the area colonized by macrophytes from 1959 to 2009-2010, the fish diversity declined markedly, and species numbers of herbivores and piscivores declined proportionately more than those of invertivores, omnivores, and planktivores. The decline of potamophilus and river-lake migratory fish was more marked than those of sedentary, river-sea migratory, and estuarine fishes. Eutrophication concomitant with sharp reduction of macrophyte area and overfishing may be the main reasons for the decline in fish diversity in Dianshan Lake. Pearson, Daniel K.; Braun, Christopher L.; Moring, J. Bruce This report documents differences in the mapped spatial extents and physical characteristics of in-channel fish habitat evaluated at the mesohabitat scale during winter 2011–12 (moderate streamflow) and summer 2012 (low streamflow) at 15 sites on the Middle Rio Grande in New Mexico starting about 3 kilometers downstream from Cochiti Dam and ending about 40 kilometers upstream from Elephant Butte Reservoir. The results of mesohabitat mapping, physical characterization, and fish assemblage surveys are summarized from the data that were collected. The report also presents general comparisons of physical mesohabitat data, such as wetted area and substrate type, and biological mesohabitat data, which included fish assemblage composition, species richness, Rio Grande silvery minnow relative abundance, and Rio Grande silvery minnow catch per unit effort. Richard M. Starr Full Text Available The deepwater faunas of oceanic islands and seamounts of the Eastern Tropical Pacific are poorly known. From 11-22 September 2009 we conducted an exploration of the deepwater areas of the Isla del Coco Marine Conservation Area, Costa Rica and a nearby seamount using a manned submersible. The goal of the exploration was to characterize the habitats and biota, and conduct quantitative surveys of the deepwater portions of Isla del Coco National Park and Las Gemelas Seamount, located about 50km southwest of Isla del Coco. We completed a total of 22 submersible dives, spanning more than 80hr underwater, and collected a total of 36hr of video. We surveyed habitats from 50-402m and observed more than 45 species of fishes, some of which have not yet been described and are likely new to science. The diversity of fish species in deep water at Isla del Coco National Park was lower than the diversity of fishes in shallow water, and eight species groups accounted for more than 95% of the total fish biomass. The combined density of all fish species was higher at Las Gemelas Seamount (253 fishes/100m² than at Isla del Coco National Park (138 fishes/100m². The combined density of fishes in habitats comprised primarily of bedrock or large boulders outcrops was more than three times as high at Las Gemelas Seamount as it was at Isla del Coco National Park. This discrepancy was caused by the extremely high concentration of Anthiinae fishes in rocky habitats at Las Gemelas Seamount. Densities of fishes in the other habitats were similar between the two sites. Similarly, when estimates of fish density were plotted by slope categories the density was much greater on steep slopes, which were usually comprised of rock habitats. Also, the density of fishes was greatest on high rugosity habitats. Results of these submersible surveys indicate that seamounts in the tropical eastern Pacific Ocean may be an important source of biodiversity and that more quantitative surveys Rice, J.; Gislason, Henrik data. The shape showed no overall trend, but diversity of smaller size classes showed a different temporal pattern from the diversity of intermediate and large size classes. The patterns in modelled output are consistent with, but do not prove, the hypothesis that trophic interactions are an important...... were very similar. Annual abundance spectra were linear and slopes increased significantly and fairly smoothly over the 20 years? indicating significant effects of fishing on the size composition of the exploited fish assemblage. The annual diversity spectra were more dome-shaped than in the survey...... factor in the fish community structure in the North Sea. (C) 1996 International Council for the Exploration of the Sea.... Mafalda Júnior Paulo Full Text Available Two ichthyoplankton surveys were conducted during July 1994 and July 1995 in the Gulf of Cádiz with the aim of describing composition, abundance, distribution patterns and interannual variations of larval fish assemblages. Interannual differences were found in this study. In 1994, higher salinities were observed at external sites, though in 1995, higher values were observed at intermediate sites. The upper water column was warmer in 1994 and had less fish larvae density. During 1994, Sardinella aurita and Engraulis encrasicolus were abundant but spatial location was opposite. In 1995, abundance of both species was very different, but with similar spatial pattern. Cluster analysis revealed well-defined groups of stations and assemblages of larvae, primarily related to bathymetry. The "inshore assemblage" occupied the shallow coast area; its characteristics species being closely related to the estuarine system, mainly comprising Engraulis encrasicolus and Gobiidae. The "shelf assemblage" occupied the continental shelf and its characteristics species consisted of larvae whose adults inhabited the shelf province and spawn in the same zone, like Sardinella aurita and Trachurus spp. Interannual variations in composition and extension of the subgroups could be attributed to the main circulation patterns, continental water discharge and spawning strategies of fishes. Rao, S. T.; Krishnaswamy, J.; Bhalla, R. S. Alteration of natural flow regimes is considered as a major threat to freshwater fish assemblages as it disturbs the water quality and micro-habitat features of rivers. Small hydro-power (SHP), which is being promoted as a clean and green substitute for large hydro-power generation, alters the natural flow regime of head-water streams by flow diversion and regulation. The effects of altered flow regime on tropical stream fish assemblages, driven by seasonality induced perturbations to water quality and microhabitat parameters are largely understudied. My study examined the potential consequences of flow alteration by SHPs on fish assemblages in two tributaries of the west-flowing Yettinahole River which flows through the reserved forests of Sakleshpur in the Western Ghats of Karnataka. The flow in one of the tributaries followed natural flow regime while the other comprised three regimes: a near-natural flow regime above the dam, rapidly varying discharge below the dam and a dewatered regime caused by flow diversion. The study found that the altered flow regime differed from natural flow regime in terms of water quality, microhabitat heterogeneity and fish assemblage response, each indicative of the type of flow alteration. Fish assemblage in the natural flow regime was characterized by a higher catch per site, a strong association of endemic and trophic specialist species. The flow regime above the dam was found to mimic some components of the natural flow regime, both ecological and environmental. Non endemic, generalist and pool tolerant species were associated with the dewatered regime. There was a lack of strong species-regime association and an overall low catch per site for the flow regulated regime below the dam. This study highlights the consequences of altered flows on the composition of freshwater fish assemblages and portrays the potential of freshwater fish as indicators of the degree and extent of flow alteration. The study recommends the need for A six-year survey (1993 - 1998) is summarized for fish collected from chemically-contaminated, urbanized bayous in northwest Florida. Fifty-two monthly collections (January - November) were conducted by trawls and seines at 22 sites located in three adjacent bayous associated wi... Darling, Ruth A. Presents a biology laboratory experiment designed to examine the ability of fish to improve their foraging rate with experience. This project is appropriate for ecology and animal behavior courses as well as introductory biology courses with a component that provides students with experience in designing and conducting scientific experiments.… Andrews, Caroline S.; Miranda, Leandro E.; Goetz, Daniel B.; Kroger, Robert In the alluvial valley of the lower Mississippi River, floodplain lakes form isolated aquatic fragments that retain differing degrees of connectivity to neighbouring rivers. Within these floodplain lakes it was hypothesized that fish species composition, relative abundance, and biodiversity metrics would be shaped largely by aquatic connectivity within a catchment. Ara, Roushon; Arshad, Aziz; Amin, S M Nurul; Idris, M H; Gaffar, Mazlan Abd; Romano, Nicholas Our previous study demonstrated that among different habitat sites (mangrove, estuary, river, seagrass and Open Sea) in Johor Strait, Malaysia, seagrass showed highest family diversity and abundance of larval fish. However, it is unclear whether this was due to difference in habitat complexity or water quality parameters.? To test this, larval fish were collected by using a bongo net equipped with a flow meter by subsurface horizontal towing from different habitats in Johor Strait between October 2007 and September 2008.? Various physico-chemical parameters were measured and then examined for any relationship to fish larvae diversity and abundance. Among the 24 families identified from the sites, seven families (Blenniidae, Clupeidae, Mullidae, Nemipteridae, Syngnathidae, Terapontidae and Uranoscopeidae) were significantly correlated with the tested waters quality parameters.? Salinity showed a positive and negative significant correlation with Clupeidae (p Johor Strait, Malaysia. This likely indicates that habitat structure was more important in determining larval abundance (highest in the seagrass habitat) as compared to water quality at the tested sites. This study emphasizes the need to conserve seagrass beds as important nursery grounds for various fish larvae to ensure adequate recruitment and ultimately sustainable fisheries management. ? Muška, Milan; Vašek, Mojmír; Modrý, David; Jirků, Miloslav; Ojwang, W. O.; Malala, J. O.; Kubečka, Jan Roč. 38, č. 1 (2012), s. 98-106 ISSN 0380-1330 R&D Projects: GA AV ČR(CZ) KJB600960813 Institutional support: RVO:60077344 Keywords : African lakes * acoustics * fish distribution * endorheic basin * lates Subject RIV: EH - Ecology, Behaviour Impact factor: 2.309, year: 2012 Schmutz, S.; Jurajda, Pavel; Kaufmann, S.; Lorenz, A. W.; Muhar, S.; Paillex, A.; Poppe, M.; Wolter, C. Roč. 769, č. 1 (2016), s. 67-78 ISSN 0018-8158 Institutional support: RVO:68081766 Keywords : Restoration success * Effect size * Rheophilic fish * Restoration monitoring * Hydromorphological quality * Restored section length Subject RIV: EH - Ecology, Behaviour Impact factor: 2.056, year: 2016 Bret C. Harvey; Jason L. White; Rodney J. Nakamoto While two cyprinid fishes introduced from nearby drainages have become widespread and abundant in the Eel River of northwestern California, a third nonindigenous cyprinid has remained largely confined to <25 km of one major tributary (the Van Duzen River) for at least 15 years. The downstream limit of this species, speckled dace, does not appear to correspond... Li, Junyi; Zhang, Hui; Lin, Danqing; Wu, Jinming; Wang, Chengyou; Xie, Xuan Now more and more ecologists concern about the impacts of dam construction on fish. However, studies of fishes downstream Gezhouba Dam were rarely reported except Chinese sturgeon (Acipenser sinensis Gray). In this study, catch investigations and five hydroacoustic detections were completed from 2015 to 2016 to understand the distribution, size, and categories of fishes and their relationship with the environmental factors below Gezhouba Dam in protected reach in the Yangtze River main stream. Results showed significant differences in fish distribution and TS (target strength) between wet and flood seasons. Mean TS in five hydroacoustic detections were −59.98 dB, −54.70 dB, −56.16 dB, −57.90 dB, and −59.17 dB, respectively, and dominant fish species are Coreius guichenoti (Bleeker), Siniperca chuatsi (Basilewsky), and Pelteobagrus vachelli (Richardson). In the longitudinal direction, fish preferred to stay in some specific sections like reaches 2, 4, 7, 8, 11, and 16. Since hydrology factors change greatly in different seasons, environmental characteristics vary along the reaches, and human activities play an important role in the fish behavior, it is concluded that great cross-season changes in hydrology lead to the differences in TS and fish assemblages and that geography characteristics, especially channel geography, together with human activities influence fish longitudinal distribution. This finding provides basic knowledge of spatiotemporal distribution and assemblages of fishes in the extended reaches downstream Gezhouba Dam. In addition, it offers implications for river management. It could also serve as reference of future research on fish habitat. PMID:27843943 Cachera, M.; Ernande, B.; Villanueva, M. C.; Lefebvre, S. Individual diet variation (i.e. diet variation among individuals) impacts intra- and inter-specific interactions. Investigating its sources and relationship with species trophic niche organization is important for understanding community structure and dynamics. Individual diet variation may increase with intra-specific phenotypic (or "individual state") variation and habitat variability, according to Optimal Foraging Theory (OFT), and with species trophic niche width, according to the Niche Variation Hypothesis (NVH). OFT proposes "proximate sources" of individual diet variation such as variations in habitat or size whereas NVH relies on "ultimate sources" related to the competitive balance between intra- and inter-specific competitions. The latter implies as a corollary that species trophic niche overlap, taken as inter-specific competition measure, decreases as species niche width and individual niche variation increase. We tested the complementary predictions of OFT and NVH in a marine fish assemblage using stomach content data and associated trophic niche metrics. The NVH predictions were tested between species of the assemblage and decomposed into a between- and a within-functional group component to assess the potential influence of species' ecological function. For most species, individual diet variation and niche overlap were consistently larger than expected. Individual diet variation increased with intra-specific variability in individual state and habitat, as expected from OFT. It also increased with species niche width but in compliance with the null expectation, thus not supporting the NVH. In contrast, species niche overlap increased significantly less than null expectation with both species niche width and individual diet variation, supporting NVH corollary. The between- and within-functional group components of the NVH relationships were consistent with those between species at the assemblage level. Changing the number of prey categories used to Mariela Domiciano Ribeiro Full Text Available Abstract Functional traits are important for understanding the links between species occurrence and environmental conditions. Identifying these links makes it possible to predict changes in species composition within communities under specific environmental conditions. We used functional traits related to habitat use and trophic ecology in order to assess the changes in fish community composition between streams with varying habitat structure. The relationship between the species traits and habitat characteristics was analyzed using an RLQ ordination analysis. Although species were widely distributed in habitats with different structures, physical conditions did favor some species based on their functional characteristics. Eight functional traits were found to be associated with stream habitat structure, allowing us to identify traits that may predict the susceptibility of fish species to physical habitat degradation. Dias, Murilo S; Magnusson, William E; Zuanon, Jansen In Amazonia reduced-impact logging, which is meant to reduce environmental disturbance by controlling stem-fall directions and minimizing construction of access roads, has been applied to large areas containing thousands of streams. We investigated the effects of reduced-impact logging on environmental variables and the composition of fish in forest streams in a commercial logging concession in central Amazonia, Amazonas State, Brazil. To evaluate short-term effects, we sampled 11 streams before and after logging in one harvest area. We evaluated medium-term effects by comparing streams in 11 harvest areas logged 1-8 years before the study with control streams in adjacent areas. Each sampling unit was a 50-m stream section. The tetras Pyrrhulina brevis and Hemigrammus cf. pretoensis had higher abundances in plots logged > or =3 years before compared with plots logged fish composition did not differ two months before and immediately after reduced-impact logging. Temperature and pH varied before and after logging, but those differences were compatible with normal seasonal variation. In the medium term, temperature and cover of logs were lower in logged plots. Differences in ordination scores on the basis of relative fish abundance between streams in control and logged areas changed with time since logging, mainly because some common species increased in abundance after logging. There was no evidence of species loss from the logging concession, but differences in log cover and ordination scores derived from relative abundance of fish species persisted even after 8 years. For Amazonian streams, reduced-impact logging appears to be a viable alternative to clear-cut practices, which severely affect aquatic communities. Nevertheless, detailed studies are necessary to evaluated subtle long-term effects. Izaias M Fernandes Full Text Available The influence of habitat, biomass of herbaceous vegetation, depth and distance from permanent water bodies on the structure of fish assemblages of a seasonal floodplain was evaluated using data collected along 22 transects in an area of 25 km² in the floodplain of Cuiabá River, Pantanal, Brazil. Each transect was sampled for fish using throw traps and gillnets during the flood period of 2006. Multivariate multiple regression analysis and multivariate analysis of covariance indicated that depth was the only variable that affected the structure of the fish assemblage, both for quantitative data (abundance and qualitative data (presence-absence. Species such as Neofundulus parvipinnis and Laetacara dorsigera were more abundant in shallower sites (below 25 cm, while Serrasalmus maculatus and Metynnis mola were found mostly in the deepest areas (over 55 cm. However, species such as Hoplias malabaricus and Hoplerythrinus unitaeniatus occurred at all sampled depths. Although the distribution of most species was restricted to a few sites, there was a positive relationship between species richness and depth of the water body. Surprisingly, the replacement of native vegetation by exotic pasture did not affect the fish assemblage in the area, at the probability level considered. Torgersen, Christian E.; Hockman-Wert, David P.; Bateman, Douglas S.; Leer, David W.; Gresswell, Robert E. The Lower Crooked River is a remarkable groundwater-fed stream flowing through vertical basalt canyons in the Deschutes River Valley ecoregion in central Oregon (Pater and others, 1998). The 9-mile section of the river between the Crooked River National Grasslands boundary near Ogden Wayside and river mile (RM) 8 is protected under the National Wild and Scenic Rivers Act (16 U.S.C. 1271-1287) for its outstandingly remarkable scenic, recreational, geologic, hydrologic, wildlife, and botanical values (ORVs), and significant fishery and cultural values. Groundwater springs flow directly out of the canyon walls into the Lower Crooked River and create a unique hydrologic setting for native coldwater fish, such as inland Columbia Basin redband trout (Oncorhynchus mykiss gairdneri). To protect and enhance the ORVs that are the basis for the wild and scenic designation, the Bureau of Land Management (BLM) has identified the need to evaluate, among other conditions, fish presence and habitat use of the Lower Crooked River. The results of this and other studies will provide a scientific basis for communication and cooperation between the BLM, Oregon Water Resources Department, Oregon Department of Fish and Wildlife (ODFW) and all water users within the basin. These biological studies initiated by the BLM in the region reflect a growing national awareness of the impacts of agricultural and municipal water use on the integrity of freshwater ecosystems. Brendan P Kelaher Full Text Available Networks of no-take marine reserves and partially-protected areas (with limited fishing are being increasingly promoted as a means of conserving biodiversity. We examined changes in fish assemblages across a network of marine reserves and two different types of partially-protected areas within a marine park over the first 5 years of its establishment. We used Baited Remote Underwater Video (BRUV to quantify fish communities on rocky reefs at 20-40 m depth between 2008-2011. Each year, we sampled 12 sites in 6 no-take marine reserves and 12 sites in two types of partially-protected areas with contrasting levels of protection (n = 4 BRUV stations per site. Fish abundances were 38% greater across the network of marine reserves compared to the partially-protected areas, although not all individual reserves performed equally. Compliance actions were positively associated with marine reserve responses, while reserve size had no apparent relationship with reserve performance after 5 years. The richness and abundance of fishes did not consistently differ between the two types of partially-protected areas. There was, therefore, no evidence that the more regulated partially-protected areas had additional conservation benefits for reef fish assemblages. Overall, our results demonstrate conservation benefits to fish assemblages from a newly established network of temperate marine reserves. They also show that ecological monitoring can contribute to adaptive management of newly established marine reserve networks, but the extent of this contribution is limited by the rate of change in marine communities in response to protection. Vanessa Salete Daga Full Text Available The objective of this study was to assess the abundance, attributes of assemblages, and spatial and temporal distributions of fish larvae and their relationships with some abiotic variables in two floodplain lakes with different degrees of connection to the Paraná River in Ilha Grande National Park, PR, Brazil. Four sampling sites were chosen, two in each floodplain lake. Night samples were taken with plankton nets during three spawning seasons (monthly, from October to March from 2001 to 2005. The highest diversity and abundance were recorded at Saraiva Lake, with 25 taxa being identified. In Xambrê Lake, only sedentary species were captured, and the most abundant species were Plagioscion squamosissimus and Hypophthalmus edentatus. The greatest abundance of larvae was found in the second spawning season. In the Saraiva Lake, the most abundant species were Moenkhausia aff. intermedia, Hyphessobrycon sp., and Bryconamericus stramineus, but larvae of known migratory species were also documented. In this lake, the greatest abundance of larvae was found in the third spawning. Larvae abundance was influenced by water temperature and conductivity. The high diversity and abundance recorded in Saraiva Lake may be a result of its connectivity with the Paraná River, and the low diversity and abundance observed at Xambrê Lake are likely due to its isolation from the river. This work shows the importance of these lagoons for fish development, for both sedentary and migratory species. Both lagoons may be considered to have extreme ecological importance and they are also extremely susceptible to impacts, so any careless disturbance may cause irreversible damage. Winters, Lisa K.; Budy, Phaedra In highly managed reservoir systems, species interactions within novel fish assemblages can be difficult to predict. In high-elevation Scofield Reservoir in Utah the unintentional introduction of Utah Chub Gila atraria and subsequent population expansion prompted a shift from stocking exclusively Rainbow Trout Oncorhynchus mykiss to include tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) and Bonneville Cutthroat Trout O. clarkii utah, which composed a novel suite of top predators and potential competitors. We examined the interspecific interactions among Scofield Reservoir piscivores using a multifaceted approach including gut analyses, stable isotopes, and gape limitation. Large Cutthroat Trout consumed 50–100% Utah Chub and tiger trout consumed 45–80%. In contrast, small and large Rainbow Trout consumed primarily invertebrate prey and exhibited significant overlap with small tiger trout, Cutthroat Trout, and Utah Chub. Large Cutthroat Trout and tiger trout occupy a top piscivore trophic niche and are more littoral, while Rainbow Trout occupy an omnivore niche space and are more pelagic. Both Cutthroat and tiger trout varied in niche space with respect to size-class, demonstrating an ontogenetic shift to piscivory at approximately 350 mm TL. Cutthroat Trout and tiger trout are capable of consuming prey up to 50% of their own size, which is larger than predicted based on their theoretical gape limit. Because it appears food resources (Utah Chub) are not limited, and performance metrics are high, competition is unlikely between Cutthroat Trout and tiger trout. In contrast, apparent survival of Rainbow Trout has recently declined significantly, potentially due to shared food resources with Utah Chub or negative behavioral interactions with other members of the community. Collectively, this research aids in understanding biotic interactions within a top-heavy and novel fish community and assists towards developing Full Text Available Change in oceanographic conditions causes structural alterations in marine fish communities, but this effect may go undetected as most monitoring programs until recently mainly have focused on oceanography and commercial species rather than on whole ecosystems. In this paper, the objective is to describe the spatial and temporal changes in the Barents Sea fish community in the period 1992-2004 while taking into consideration the observed abundance and biodiversity patterns for all 82 observed fish species. We found that the spatial structure of the Barents Sea fish community was determined by abiotic factors such as temperature and depth. The observed species clustered into a deep assemblage, a warm water southern assemblage, both associated with Atlantic water, and a cold water north-eastern assemblage associated with mixed water. The latitude of the cold water NE and warm water S assemblages varied from year to year, but no obvious northward migration was observed over time. In the period 1996-1999 we observed a significant reduction in total fish biomass, abundance, mean fish weight, and a change in community structure including an increase in the pelagic/demersal ratio. This change in community structure is probably due to extremely cold conditions in 1996 impacting on a fish community exposed to historically high fishing rates. After 1999 the fish community variables such as biomass, abundance, mean weight, P/D ratio as well as community composition did not return to levels of the early 90s, although fishing pressure and climatic conditions returned to earlier levels. Olivar, M. Pilar; Sabatés, Ana; Pastor, Maria V.; Pelegrí, Josep L. We explore the associations between larval fish assemblages and oceanographic conditions in the upper ocean (top 200 m) along the African slope, from tropical (15°N) to subtropical (35°N) latitudes, during a period of intense upwelling. In this extensive region, the northward Mauritanian Current and Poleward Undercurrent carry South Atlantic Central Waters (SACW) while the southward Canary Upwelling Current transports North Atlantic Central Waters (NACW). South of Cape Blanc we only find SACW, and north of Cape Blanc there is NACW far offshore and a combination of NACW and SACW nearshore, separated by the Canary Upwelling Front (CUF). The larvae of different myctophid species serve as indicators of the water masses, e.g. S. veranyi and M. punctatum were found in some coastal stations that were dominated by NACW, while the tropical mesopelagic B. argyrogaster, H. macrochir, M. affine and S. kreffti were associated to the SACW. The along-slope offshore convergence of NACW and SACW takes place at the Cape Verde Frontal Zone (CVFZ), representing a region of extensive offshore export for larvae of coastal species, S. pilchardus and E. encrasicolus, far from their nearshore spawning area. The large-scale frontal systems (CVFZ and CUF) and mesoscale eddies contribute to retain larvae within productive waters, influencing both coastal and oceanic species. Quiroz-Martínez, Benjamín; Salgado-Maldonado, Guillermo In this paper, we analyse the distributional patterns of adult helminth parasites of freshwater fishes with respect to the main hydrological basins of Mexico. We use the taxonomic distinctness and the variation in taxonomic distinctness to explore patterns of parasite diversity and how these patterns change between zoogeographical regions. We address questions about the factors that determine the variation of observed diversity of helminths between basins. We also investigate patterns of richness, taxonomic distinctness and distance decay of similarity amongst basins. Our analyses suggest that the evolution of the fauna of helminth parasites in Mexico is mostly dominated by independent host colonization events and that intra--host speciation could be a minor factor explaining the origin of this diversity. This paper points out a clear separation between the helminth faunas of northern--nearctic and southern--neotropical components in Mexican continental waters, suggesting the availability of two distinct taxonomic pools of parasites in Mexican drainage basins. Data identifies Mexican drainage basins as unities inhabited by freshwater fishes, hosting a mixture of neotropical and nearctic species, in addition, data confirms neotropical and neartic basins/helminth faunas. The neotropical basins of Mexico are host to a richest and more diversified helminth fauna, including more families, genera and species, compared to the less rich and less diverse helminth fauna in the nearctic basins. The present analysis confirms distance--decay as one of the important factors contributing to the patterns of diversity observed. The hypothesis that helminth diversity could be explained by the ichthyological diversity of the basin received no support from present analysis. Full Text Available In this paper, we analyse the distributional patterns of adult helminth parasites of freshwater fishes with respect to the main hydrological basins of Mexico. We use the taxonomic distinctness and the variation in taxonomic distinctness to explore patterns of parasite diversity and how these patterns change between zoogeographical regions. We address questions about the factors that determine the variation of observed diversity of helminths between basins. We also investigate patterns of richness, taxonomic distinctness and distance decay of similarity amongst basins. Our analyses suggest that the evolution of the fauna of helminth parasites in Mexico is mostly dominated by independent host colonization events and that intra--host speciation could be a minor factor explaining the origin of this diversity. This paper points out a clear separation between the helminth faunas of northern--nearctic and southern--neotropical components in Mexican continental waters, suggesting the availability of two distinct taxonomic pools of parasites in Mexican drainage basins. Data identifies Mexican drainage basins as unities inhabited by freshwater fishes, hosting a mixture of neotropical and nearctic species, in addition, data confirms neotropical and neartic basins/helminth faunas. The neotropical basins of Mexico are host to a richest and more diversified helminth fauna, including more families, genera and species, compared to the less rich and less diverse helminth fauna in the nearctic basins. The present analysis confirms distance--decay as one of the important factors contributing to the patterns of diversity observed. The hypothesis that helminth diversity could be explained by the ichthyological diversity of the basin received no support from present analysis. Pérez-Ruzafa, A; García-Charton, J A; Barcala, E; Marcos, C The benthic fish assemblage of the Mar Menor consisted of 37 species. Dominant species are: Gobius cobitis, Lipophrys pavo and Tripterygion tripteronotus on infralittoral rocks; Pomatoschistus marmoratus, Callionymus pussillus, Callionymus risso and Solea vulgaris on sandy bottoms and Gobius niger, Syngnathus abaster, Hippocampus ramulosus and Symphodus cinereus on Cymodocea nodosa-Caulerpa prolifera mixed beds. From 1985 to 1989 tourist development has led to the creation of new beaches and the installation of artificial rocky structures for retaining sediments. Dredging for the extraction of sand and subsequent pumping altered sediment characteristics causing a real stress leading to the substitution of typical sandy bottoms communities with Cymodocea nodosa by Caulerpa prolifera communities on mud. Soft bottom fish assemblages responded to changes in vegetation cover and substratum characteristics mainly changing the species composition, while artificial hard substrata contain a similar fish community than natural ones, harbouring even richer and more diverse assemblages. This positive effect of breakwaters should not obscure their likely negative effects on hydrodynamics and the subsequent changes of sediment quality and vegetation cover on the breakwaters' area of influence. Full Text Available Coastal lagoons are important systems for freshwater, estuarine and marine organisms; they are considered important zones of reproduction, nursery and feeding for many fish species. The present study investigates the fish assemblages of the natural reserve of Dzilam and their relationship with the hydrologic variables. A total of 6 474 individuals (81 species were collected, contributing with more than 50% considering the Importance Value Index (IVI, Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon. Differences in species composition were found between seasons the highest during the cold fronts. Spatially, differences were related with the presence of freshwater seeps, the highest in the ecological characterized eastern part and the lowest with higher difference in specific composition located in the western part of the internal zone, due to a higher abundance and dominance of L. rhomboides. Salinity and temperature were the variables that presented a higher influence in the distribution of some pelagic species such as A. mitchilli and A. hepsetus. Because of the abundant freshwater seeps characteristic of the coastal lagoons of Yucatan Peninsula their community structure and fish assemblage display spatial and temporal differences in specific composition. Rev. Biol. Trop. 57 (1-2: 89-103. Epub 2009 June 30.Las lagunas costeras son sistemas importantes para muchas especies de organismos dulceacuícolas, estuarinos y marinos, ya que son consideradas zonas de reproducción, refugio y alimentación de muchas especies de peces. El presente estudio analizó los ensamblajes de la comunidad íctica de la reserva de Dzilam y su relación con las variables hidrológicas. Se capturaron un total de 6 474 individuos (81 especies, en donde Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon contribuyeron con m Miguel Angel Peralta-Meixueiro Full Text Available The spatial and temporal fish species assemblages were analyzed throughout two annual cycles (2004-2005 and 2007-2008 in the Ría Lagartos Lagoon system, Mexico, via non-parametric multivariate analyses. We compared density and biomass of fish species among five habitat types defined by combinations of structure and environmental characteristics (hyperhaline, rocky, seagrass, channel, and marine, and three climatic seasons (dry, rainy, and northerlies. A total of 11,187 individuals distributed in 32 families and 63 species were collected. The most numerically abundant species were Floridichthys polyommus and Cyprinodon artifrons, while Sphoeroides testudineus contributed to the greatest biomass. Species composition consisted mainly of estuarine and euryhaline marine species. Spatially, a saline gradient was observed with marine conditions in the mouth, and increasing to over 100 in the inner zone of the system. Species richness, diversity and biomass declined from the mouth to the inner zone, while density showed an inverse tendency, with the highest values in the inner zone. Thus the salinity was the variable that best explained the spatial fish assemblages" structure. The ichthyofauna composition did not change over time, but the dominant species varied with the years. The abundance of juvenile specimens, suggest that the different habitats are used as feeding and breeding zones; hence it is proposed that protection strategies be pursued not only for the lagoon system but also for the northern zone of the Yucatan Peninsula.Los ensamblajes espacio temporales de peces fueron analizados a través de dos ciclos anuales (2004-2005 y 2007-2008 en el sistema lagunar Ría Lagartos, México, vía análisis multivariados no paramétricos. Se comparó la densidad y biomasa de peces entre los cinco tipos de hábitats definidos por la combinación de características estructurales y ambientales (hiperhalino, rocoso, pastos, canal y marino y tres temporadas Breeggemann, Jason J.; Kaemingk, Mark A.; DeBates, T.J.; Paukert, Craig P.; Krause, J.; Letvin, Alexander P.; Stevens, Tanner M.; Willis, David W.; Chipps, Steven R. Much uncertainty exists around how fish communities in shallow lakes will respond to climate change. In this study, we modelled the effects of increased water temperatures on consumption and growth rates of two piscivores (northern pike [Esox lucius] and largemouth bass [Micropterus salmoides]) and examined relative effects of consumption by these predators on two prey species (bluegill [Lepomis macrochirus] and yellow perch [Perca flavescens]). Bioenergetics models were used to simulate the effects of climate change on growth and food consumption using predicted 2040 and 2060 temperatures in a shallow Nebraska Sandhill lake, USA. The patterns and magnitude of daily and cumulative consumption during the growing season (April–October) were generally similar between the two predators. However, growth of northern pike was always reduced (−3 to −45% change) compared to largemouth bass that experienced subtle changes (4 to −6% change) in weight by the end of the growing season. Assuming similar population size structure and numbers of predators in 2040–2060, future consumption of bluegill and yellow perch by northern pike and largemouth bass will likely increase (range: 3–24%), necessitating greater prey biomass to meet future energy demands. The timing of increased predator consumption will likely shift towards spring and fall (compared to summer), when prey species may not be available in the quantities required. Our findings suggest that increased water temperatures may affect species at the edge of their native range (i.e. northern pike) and a potential mismatch between predator and prey could exist. Full Text Available The aim of this study was to establish phytoplankton composition at the sea bream (Sparus aurata and sea bass (Dicentrarchus labrax fish farm in the middle Adriatic Sea. The investigation was performed from September 2005 to September 2006 at a station located in Maslinova Bay at the island of Brač. Considering the whole research period, diatoms generally prevailed in terms of abundance while dinoflagellates were particularly abundant in June. Number of species of diatoms in comparison to dinoflagellates through the investigated period was similar. From 111 species of phytoplankton found, there were 55 species of Bacillariophyceae (diatoms, 47 species of Dinophyta (dinoflagellates, 5 species of Prymnesiophyceae, 3 Chrysophyceae and 1 Euglenophyta. Among the diatoms, the majority of species belonged to genus Chaetoceros. The most represented dinoflagellate genera were Oxytoxum and Gymnodinium. There were no considerable differences in phytoplankton composition with respect to different depths, but seasonal influence was significant. Biodiversity and abundance ranges of phytoplankton species indicated good water conditions and there were no evident alterations induced by the increased release of nutrients. Falke, Jeffrey A; Bailey, Larissa L; Fausch, Kurt D; Bestgen, Kevin R Despite the importance of habitat in determining species distribution and persistence, habitat dynamics are rarely modeled in studies of metapopulations. We used an integrated habitat-occupancy model to simultaneously quantify habitat change, site fidelity, and local colonization and extinction rates for larvae of a suite of Great Plains stream fishes in the Arikaree River, eastern Colorado, USA, across three years. Sites were located along a gradient of flow intermittency and groundwater connectivity. Hydrology varied across years: the first and third being relatively wet and the second dry. Despite hydrologic variation, our results indicated that site suitability was random from one year to the next. Occupancy probabilities were also independent of previous habitat and occupancy state for most species, indicating little site fidelity. Climate and groundwater connectivity were important drivers of local extinction and colonization, but the importance of groundwater differed between periods. Across species, site extinction probabilities were highest during the transition from wet to dry conditions (range: 0.52-0.98), and the effect of groundwater was apparent with higher extinction probabilities for sites not fed by groundwater. Colonization probabilities during this period were relatively low for both previously dry sites (range: 0.02-0.38) and previously wet sites (range: 0.02-0.43). In contrast, no sites dried or remained dry during the transition from dry to wet conditions, yielding lower but still substantial extinction probabilities (range: 0.16-0.63) and higher colonization probabilities (range: 0.06-0.86), with little difference among sites with and without groundwater. This approach of jointly modeling both habitat change and species occupancy will likely be useful to incorporate effects of dynamic habitat on metapopulation processes and to better inform appropriate conservation actions. UIEDA V. S. Full Text Available The species composition and spatial distribution of a fish assemblage were studied in three reaches of a river in the east coast of Brazil: a section of rapids (upper, another of water flowing on plain terrain (lowland and the other of a mangrove environment. Two methods were employed with the purpose of estimating their effectiveness in naturalistic studies of tropical fish assemblages. One method consisted of underwater observations and the other was characterized by catches using gears such as fish traps, sieves and fishing rods. Both methods showed that their effectiveness is dependent upon the characteristics of the environment and the biology of the species. In areas of high water transparency and flow speed, rocky substrate and no submerged marginal vegetation (upper reach, the employment of the traditional gears was quite inefficient, despite the excellent conditions for underwater observations. In areas of clear water and high flow speed with abundant submerged marginal vegetation (lowland and mangrove, the gears were rather efficient yielding excellent results when coupled with direct observation methods. Since the abiotic characteristics of a stream change longitudinally, it is appropriate to employ different methods in the study of the ichthyofauna composition and distribution in order to reduce the constraints imposed by sampling methods in running waters. V. S. UIEDA Full Text Available The species composition and spatial distribution of a fish assemblage were studied in three reaches of a river in the east coast of Brazil: a section of rapids (upper, another of water flowing on plain terrain (lowland and the other of a mangrove environment. Two methods were employed with the purpose of estimating their effectiveness in naturalistic studies of tropical fish assemblages. One method consisted of underwater observations and the other was characterized by catches using gears such as fish traps, sieves and fishing rods. Both methods showed that their effectiveness is dependent upon the characteristics of the environment and the biology of the species. In areas of high water transparency and flow speed, rocky substrate and no submerged marginal vegetation (upper reach, the employment of the traditional gears was quite inefficient, despite the excellent conditions for underwater observations. In areas of clear water and high flow speed with abundant submerged marginal vegetation (lowland and mangrove, the gears were rather efficient yielding excellent results when coupled with direct observation methods. Since the abiotic characteristics of a stream change longitudinally, it is appropriate to employ different methods in the study of the ichthyofauna composition and distribution in order to reduce the constraints imposed by sampling methods in running waters. Josias Henrique de Amorim Xavier Full Text Available Reefs, mangroves and seagrass biotopes often occur in close association, forming a complex and highly productive ecosystem that provide significant ecologic and economic goods and services. Different anthropogenic disturbances are increasingly affecting these tropical coastal habitats leading to growing conservation concern. In this field-based study, we used a visual census technique (belt transects 50 m x 2 m to investigate the interactions between fishes and microhabitats at the Mamanguape Mangrove-Reef system, NE Brazil. Overall, 144 belt transects were performed from October 2007 to September 2008 to assess the structure of the fish assemblage. Fish trophic groups and life stage (juveniles and adults were recorded according to literature, the percent cover of the substrate was estimated using the point contact method. Our results revealed that fish composition gradually changed from the Estuarine to the Reef zone, and that fish assemblage was strongly related to the microhabitat availability, as suggested by the predominance of carnivores at the Estuarine zone and presence of herbivores at the Reef zone. Fish abundance and diversity were higher in the Reef zone and estuary margins, highlighting the importance of structural complexity. A pattern of nursery area utilization, with larger specimens at the Transition and Reef Zone and smaller individuals at the Estuarine zone, was recorded for Abudefduf saxatilis, Anisotremus surinamensis, Lutjanus alexandrei, and Lutjanus jocu. Our findings clearly suggests ecosystem connectivity between mangrove, seagrass and reef biotopes, and highlighted the importance of Mamanguape Mangrove-Reef System as a priority area for conservation and research, whose habitat mosaics should be further studied and protected. Full Text Available The by-catch of sharks in artisanal demersal pink cusk-eel (Genypterus blacodes and yellownose skate (Dipturus chilensis fisheries is frequent within their fishing effort. Nevertheless, there is no registry of landings, which could help to control this problem. This is particularly evident for endemic species, which includes most coastal and deep water Chilean sharks. The main systematic characteristic of these Chondrichthyan species is the external morphology of the neurocraneum. The form and arrangement of the teeth and dermal denticles allow specific differences to be identified. The objective of this paper is to contribute to the biology and systematic knowledge of demersal shark species, teeth and dermal denticle morphology and neurocraneum morphometrics of two species of Scyliorhinids, the redspotted catshark (Schroederichthys chilensis and the dusky catshark (Halaelurus canescens, as well as three Squaliforms, the granular dogfish (Centroscyllium granulatum, the birdbeak dogfish (Deania calcea and the spiny dogfish (Squalus acanthias. Novaes, J L C; Moreira, S I L; Freire, C E C; Sousa, M M O; Costa, R S The aim of this study was to analyse the composition, structure and spatial and temporal patterns of diversity and abundance of the ichthyofauna of the Santa Cruz Reservoir in semi-arid Brazil. Data were collected quarterly at eight sampling locations on the reservoir between February 2010 and November 2011 using gillnets from 12- to 70-mm mesh that were left in the water for 12h00min during the night. We evaluated the composition, structure and assemblage descriptors (Shannon-Wiener diversity index and equitability, respectively) and catch per unit effort by the number (CPUEn) and biomass (CPUEb) of the ichthyofauna. The 6,047 individuals (399,211.6 g) captured represented three orders, ten families and 20 species, of which four belonged to introduced species. The family Characidae was the most abundant with a total of 2,772 (45.8%) individuals captured. The species-abundance curve fit the log-normal model. In the spatial analysis of diversity, there were significant differences between sampling sites in the lacustrine and fluvial regions, and the highest values were found in the lacustrine region. In the temporal analysis of diversity, significant differences were also observed between the rainy and dry seasons, and the higher values were found during the dry season. Equitability followed the same spatiotemporal pattern as diversity. The Spearman correlation was significantly negative between diversity and rainfall. A cluster analysis spatially separated the ichthyofauna into two groups: one group formed by sampling sites in the fluvial region and another group formed by the remainder of the points in the lacustrine region. Both the CPUEn and CPUEb values were higher at point 8 (fluvial region) and during the rainy season. A two-way ANOVA showed that the CPUEn and CPUEb values were spatially and temporally significant. We conclude that the spatial and temporal trends of diversity in the Santa Cruz reservoir differ from those of other Brazilian reservoirs but that Demarques Ribeiro da Silva Junior Full Text Available Dredging and dredge-spoil disposal are among the major problems in coastal management. Many of the scientific contributions concerning the impacts of this practice are based on the study of sessile organisms and subtropical environments. We evaluated changes in the composition and abundance of a fish assemblage resulting from dredging and sediment disposal at the mouth and in the adjacent waters of the Caravelas River on the north-eastern coast of Brazil. Samples were collected in two directly impacted and three adjacent areas. Differences among stations were not significant, but the dredged site had the least diverse station, as expected. The stations farthest from the directly impacted areas apparently were not influenced by the coastal work, thus suggesting localised effects. The contribution of the present study is particularly important because of the study area's proximity to others that have high conservation value such as mangrove forests and coral reefs, and the relevance of the subject given the continuing dredging activity.A dragagem e descarte de sedimento se destacam como atividades que geram grandes distúrbios aos ecossistemas marinhos e, consequentemente tornam-se um desafio ao manejo e ordenamento costeiro. Grande parte dos estudos que abordam seus impactos é baseada em pesquisas com organismos sésseis e em ambientes temperados, criando uma lacuna no entendimento de seus efeitos sobre a ictiofauna, principalmente nas regiões tropicais. No presente estudo foram avaliadas as alterações na composição e abundância da comunidade de peixes sob influência da dragagem e descarte de sedimento na foz do Rio Caravelas, costa da região Nordeste do Brasil. As amostras foram obtidas em duas estações diretamente afetadas e em três outras áreas adjacentes. Não houve diferença significativa na diversidade média obtida para cada estação, porém a estação correspondente à área dragada apresentou o menor valor dentre as Azevedo, Márcia Cristina Costa; Gomes-Gonçalves, Rafaela de Sousa; Mattos, Tailan Moretti; Uehara, Wagner; Guedes, Gustavo Henrique Soares; Araújo, Francisco Gerson Several species of marine fish use different coastal systems especially during their early development. However, these habitats are jeopardized by anthropogenic influences threatening the success of fish populations, and urgent measures are needed to priorize areas to protect their sustainability. We applied taxonomic (Δ+) and functional (X+) distinctiveness indices that represent taxonomic composition and functional roles to assess biodiversity of three different costal systems: bays, coastal lagoons and oceanic beaches. We hypothesized that difference in habitat characteristics, especially in the more dynamism and habitat homogeneity of oceanic beaches compared with more habitat diversity and sheltered conditions of bays and coastal lagoons results in differences in fish richness and taxonomic and functional diversity. The main premise is that communities phylogenetically and functionally more distinct have more interest in conservation policies. Significant differences (P PERMANOVA. Fish richness was higher in bays compared with the coastal lagoons and oceanic beaches. Higher Δ+ was found for the coastal lagoons compared with the bays and oceanic beaches, with the bays having some values below the confidence limit. Similar patterns were found for X+, although all values were within the confidence limits for the bays, suggesting that the absence of some taxa does not interfere in functional diversity. The hypothesis that taxonomic and functional structure of fish assemblages differ among the three systems was accepted and we suggest that coastal lagoons should be priorized in conservation programs because they support more taxonomic and functional distinctiveness. Copyright © 2017 Elsevier Ltd. All rights reserved. Henrique Corrêa Giacomini Full Text Available The lakes in the middle rio Doce Valley (MG are suffering impacts due to the introduction of invasive fish species, mainly piscivorous species like red piranha Pygocentrus nattereri and peacock bass Cichla kelberi. Fishes were collected in bimonthly samples conducted at ten lakes along a year. The present study showed that the composition of native fish assemblages is significantly related to the presence and type of non-native species. Fish species distribution among lakes can be explained by differences in species body size: smaller native species are less concentrated in lakes with invasive piscivores, which is in accordance with the hypothesis that they have greater susceptibility to predation by invaders. Another probable cause for this correlation is the proximity of lakes to the drainage system, which could explain both the non-native incidence and the turnover of native species composition. Furthermore, temporal variability in species composition was significantly higher in invaded lakes. This last factor may be linked to seasonal flood pulses, which carry immigrant fishes from streams in the vicinity. The metacommunity framework can bring insights for future studies in such spatially structured systems, and the approach should improve our understanding of processes underlying species composition as well as help direct conservation-focused management plans. Plavan, A Acuña; Gurdek, R; Muñoz, N; Gutierrez, J M; Spósito, M; Correa, P; Caride, A The large estuaries can present long narrow branches called subestuaries or tidal creeks. These types of subsystems are distributed along the Uruguayan coast of the Río de la Plata estuary and are very important as nursery and refuge areas for fish. For the first time, the seasonal composition and abundance of the fish community of the Solís Chico subestuary was studied by using beach and gill nets. Fourteen species, mainly euryhaline (86%) presented a significant representation of juvenile stages. The fish community was dominated by Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri and Paralichthys orbignyanus, similar to adjacent subestuaries. While Micropogonias furnieri and B. aurea were the most abundant species, some other species were rarely caught. A seasonal variation of the fish assemblage abundance was detected, with higher values in autumn showing a positive correlation with temperature. Species that complete their life cycle in the Río de la Plata estuary, some of which are relevant to fisheries (64% of the analyzed species) were captured in the Solís Chico subestuary. The importance of this environment as a transitional system for some estuarine fish species is advised. Eurizângela P. Dary Full Text Available ABSTRACT This study was carried out in a section of the middle course of the Teles Pires River, a clear water river that drains ancient and highly eroded geological formations, and where five hydropower plants are planned or in construction. In this study we tested the hypothesis that local fish fauna is mainly sustained by autochthonous food resources, with modest changes in the trophic structure of fish assemblages along the hydrometric cycle. Sampling was performed every three months between July 2008 and May 2009 at seven sites distributed along a 50-km section of the river. Piscivores was the most representative group in terms of biomass, abundance and species richness, followed by herbivores, insectivores and omnivores. The trophic structure did not change significantly during the hydrometric cycle, only omnivores showed significant temporal variation in abundance. The main food resources consumed by the ichthyofauna were of autochthonous origin, mainly immature aquatic insects and fish. Eight of 34 species showed temporal variations of the food resources consumed. Our results corroborate the hypothesis that the fish fauna of large, clear water rivers can be sustained by autochthonous resources. This contributes to understanding some determinants of fish production in large Neotropical rivers. Hasegawa, K; Mori, T; Yamazaki, C The spatial scale and density-dependent effects of non-native brown trout Salmo trutta on species richness of fish assemblages were examined at 48 study sites in Mamachi Stream, a tributary of Chitose River, Hokkaido, Japan. The density of age ≥1 year S. trutta was high in the upstream side of the main stem of Mamachi Stream. Fish species richness increased with increasing area of study sites (habitat size), but the increasing magnitude of the species richness with area decreased with increasing age of ≥1 year S. trutta density. The relationships between age ≥1 year S. trutta, however, and presence-absence of each species seemed to be different among species. Species richness was also determined by location and physical environmental variables, i.e. it was high on the downstream side and in structurally complex environments. © 2016 The Fisheries Society of the British Isles. Sheppard, Jill N.; James, Nicola C.; Whitfield, Alan K.; Cowley, Paul D. Habitat variability is one of the factors influencing species richness within estuarine systems, and a loss of habitat can result in a restructuring of the estuarine ichthyofaunal assemblage, particularly if these conditions persist over long time periods. The potential effects of the loss of extensive submerged macrophyte beds ( Ruppia cirrhosa and Potamogeton pectinatus) on an estuarine fish assemblage were investigated through an analysis of a long-term seine net catch dataset from the temporarily open/closed East Kleinemonde Estuary, South Africa. Catch data for a 12-year period, encompassing six years of macrophyte presence and six years of macrophyte senescence, indicated that the loss of this habitat did not influence species richness but changes in the relative abundance of certain species were evident. A shift in dominance from vegetation-associated species to those associated with sandy environments ( e.g. members of the family Mugilidae) was observed. However, species wholly dependent on macrophytes such as the critically endangered estuarine pipefish Syngnathus watermeyeri were only recorded during years when macrophyte beds were present, while vegetation-associated species such as the sparid Rhabdosargus holubi persisted at lower levels of relative abundance. The reduced abundance of all vegetation-associated fish species during years of macrophyte senescence was probably reflective of declining food resources resulting from the loss of macrophyte beds and/or increased vulnerability to predation. Submerged beds of aquatic plants are therefore important habitats within temporarily open/closed estuaries, South Africa's dominant estuary type. Krag, Ludvig Ahm have been published in scientific journals and Paper 3 has been submitted to Fisheries Research. This review will take a broader perspective and will examine the capturing process, which is the basis for the selection process. Moreover, it discusses the existing methods and knowledge in the fields...... different species, including cod, are caught together. Demersal trawling is the predominant fishing method in Denmark, as measured by both catch value and volume. Demersal trawls also account for the highest discard rates of juvenile fish, including cod. The focus of this work was on improving......, and openings. The results show that the morphology-based simulations of size selectivity of cod can be used to explain a large part of both the within-haul and the between-haul variations previously reported from sea trials. The method can further predict the selection parameters (L50 and SR) for cod... Jurajda, Pavel; Regenda, J. Roč. 49, č. 10 (2004), s. 450-457 ISSN 1212-1819 R&D Projects: GA AV ČR IAB6093106; GA AV ČR IAA6087503 Institutional research plan: CEZ:AV0Z6093917 Keywords : YOY * inshore assemblages * River Dyje Subject RIV: EG - Zoology Impact factor: 0.227, year: 2004 http://www.cazv.cz/attachments/5-Jurajda.pdf Background/Question/Methods What species of fish might someone find in a local stream? How might that community change as a result of changes to characteristics of the stream and its watershed? PiSCES is a browser-based toolkit developed to predict a fish community for any NHD-Pl... Alan M. Friedlander Full Text Available Fishes at Isla del Coco National Park, Costa Rica, were surveyed as part of a larger scientific expedition to the area in September 2009. The average total biomass of nearshore fishes was 7.8 tonnes per ha, among the largest observed in the tropics, with apex predators such as sharks, jacks, and groupers accounting for nearly 40% of the total biomass. The abundance of reef and pelagic sharks, particularly large aggregations of threatened species such as the scalloped hammerhead shark (up to 42 hammerheads ha-1 and large schools of jacks and snappers show the capacity for high biomass in unfished ecosystems in the Eastern Tropical Pacific. However, the abundance of hammerhead and reef whitetip sharks appears to have been declining since the late 1990s, and likely causes may include increasing fishing pressure on sharks in the region and illegal fishing inside the Park. One Galapagos shark tagged on September 20, 2009 in the Isla del Coco National Park moved 255km southeast towards Malpelo Island in Colombia, when it stopped transmitting. These results contribute to the evidence that sharks conduct large-scale movements between marine protected areas (Isla del Coco, Malpelo, Galápagos in the Eastern tropical Pacific and emphasize the need for regional-scale management. More than half of the species and 90% of the individuals observed were endemic to the tropical eastern Pacific. These high biomass and endemicity values highlight the uniqueness of the fish assemblage at Isla del Coco and its importance as a global biodiversity hotspot. Ansah, Yaw Boamah; Frimpong, Emmanuel A; Amisah, Stephen Biological assessment of aquatic ecosystems is widely employed as an alternative or complement to chemical and toxicity testing due to numerous advantages of using biota to determine ecosystem condition. These advantages, especially to developing countries, include the relatively low cost and technical requirements. This study was conducted to determine the biological impacts of aquaculture operations on effluent-receiving streams in the Ashanti Region of Ghana. We collected water, fish and benthic macroinvertebrate samples from 12 aquaculture effluent-receiving streams upstream and downstream of fish farms and 12 reference streams between May and August of 2009, and then calculated structural and functional metrics for biotic assemblages. Fish species with non-guarding mode of reproduction were more abundant in reference streams than downstream (P = 0.0214) and upstream (P = 0.0251), and sand-detritus spawning fish were less predominant in reference stream than upstream (P = 0.0222) and marginally less in downstream locations (P = 0.0539). A possible subsidy-stress response of macroinvertebrate family richness and abundance was also observed, with nutrient (nitrogen) augmentation from aquaculture and other farming activities likely. Generally, there were no, or only marginal differences among locations downstream and upstream of fish farms and in reference streams in terms of several other biotic metrics considered. Therefore, the scale of impact in the future will depend not only on the management of nutrient augmentation from pond effluents, but also on the consideration of nutrient discharges from other industries like fruit and vegetable farming within the study area. National Oceanic and Atmospheric Administration, Department of Commerce — This project examined the results of the field manipulative experiment that has been set up to test the ecological effects of introduced roi on reef fish... Aho, J.M.; Anderson, C.S.; Floyd, K.B.; Negus, M.T.; Meador, M.R. Research conducted as part of the Comprehensive Cooling Water Study (CCWS) has elucidated many factors that are important to fish population and community dynamics in a variety of habitats on the Savannah River Plant (SRP). Information gained from these studies is useful in predicting fish responses to SRP operations. The overall objective of the CCWS was (1) to determine the environmental effects of SRP cooling water withdrawals and discharges and (2) to determine the significance of the cooling water impacts on the environment. The purpose of this study was to: (1) examine the effects of thermal plumes on anadromous and resident fishes, including overwintering effects, in the SRP swamp and associated tributary streams; (2) assess fish spawning and locate nursery grounds on the SRP; (3) examine the level of use of the SRP by spawning fish from the Savannah River, this objective was shared with the Savannah River Laboratory, E.I. du Pont de Nemours and Company; and (4) determine impacts of cooling-water discharges on fish population and community attributes. Five studies were designed to address the above topics. The specific objectives and a summary of the findings of each study are presented. Braun, Christopher L.; Pearson, Daniel K.; Porter, Michael D.; Moring, J. Bruce In winter 2011–12 and summer 2012, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, Albuquerque District and the U.S. Fish and Wildlife Service New Mexico Fish and Wildlife Conservation Office in Albuquerque, New Mexico, evaluated the physical characteristics and fish assemblage composition of available mesohabitats over a range of streamflows at 15 sites on the Middle Rio Grande in New Mexico. The fish assemblage of the Middle Rio Grande includes several minnow species adapted to hydrologically variable but seasonably predictable rivers, including theHybognathus amarus (Rio Grande silvery minnow), a federally listed endangered species. Gaining a better understanding of habitat usage by the Rio Grande silvery minnow was the impetus for studying physical characteristics and fish assemblages in the Middle Rio Grande during different streamflow conditions. Data were collected at all 15 sites during winter 2011–12 (moderate streamflow), and a subset was collected at the 13 most downstream sites in summer 2012 (low streamflow). Sites were grouped into four river reaches separated by diversion dams listed in downstream order (names of the diversion dams are followed by short names of the sites nearest each dam in parentheses, listed in downstream order): (1) Cochiti (Peña Blanca), (2) Angostura (Bernalillo, La Orilla, Barelas, Los Padillas), (3) Isleta (Los Lunas I, Los Lunas II, Abeytas, La Joya, Rio Salado), and (4) San Acacia (Lemitar, Arroyo del Tajo, San Pedro, Bosque del Apache I, and Bosque del Apache II). Stream habitat was mapped in the field by using a geographic information system in conjunction with a Global Positioning System. Fish assemblage composition was determined during both streamflow regimes, and fish were collected by seining in each mesohabitat where physical characteristic data (depth, velocity, dominant substrate type and size, and percent embeddedness) and water-quality properties (temperature Colin, Nicole; Villéger, Sébastien; Wilkes, Martin; de Sostoa, Adolfo; Maceda-Veiga, Alberto Trait-based ecology has been developed for decades to infer ecosystem responses to stressors based on the functional structure of communities, yet its value in species-poor systems is largely unknown. Here, we used an extensive dataset in a Spanish region highly prone to non-native fish invasions (15 catchments, N=389 sites) to assess for the first time how species-poor communities respond to large-scale environmental gradients using a taxonomic and functional trait-based approach in riverine fish. We examined total species richness and three functional trait-based indices available when many sites have ≤3 species (specialization, FSpe; originality, FOri and entropy, FEnt). We assessed the responses of these taxonomic and functional indices along gradients of altitude, water pollution, physical habitat degradation and non-native fish biomass. Whilst species richness was relatively sensitive to spatial effects, functional diversity indices were responsive across natural and anthropogenic gradients. All four diversity measures declined with altitude but this decline was modulated by physical habitat degradation (richness, FSpe and FEnt) and the non-native:total fish biomass ratio (FSpe and FOri) in ways that varied between indices. Furthermore, FSpe and FOri were significantly correlated with Total Nitrogen. Non-native fish were a major component of the taxonomic and functional structure of fish communities, raising concerns about potential misdiagnosis between invaded and environmentally-degraded river reaches. Such misdiagnosis was evident in a regional fish index widely used in official monitoring programs. We recommend the application of FSpe and FOri to extensive datasets from monitoring programs in order to generate valuable cross-system information about the impacts of non-native species and habitat degradation, even in species-poor systems. Scoring non-native species apart from habitat degradation in the indices used to determine ecosystem health is Swalethorp, Rasmus; Malanski, Evandro; Munk, Peter The recent increase in temperature and freshwater runoff in the Arctic will influence the functioning of the plankton ecosystem and hence the life of the fish larvae residing in these areas. Here, we studied the strength of physical– biological linkages and the adaptability of individual larval...... of the individual larval fish species. Larvae were feeding on a variety of prey taxa and sizes; some larval species were generalists, while others were more specialized or fed on alternative prey taxa. Differences in feeding strategies might have the consequence that the species will be differently affected... Munk, Peter; Bjørnsen, Peter Koefoed; Boonruang, P. on the sampling of fish larvae and mesozooplankton. Surveys were carried out during 2 monsoon periods in March and August 1996, using 3 cross-bathymetric transects extending to the deeper part of the shelf slope of the Andaman Sea. Station distances were either 5 or 10 n miles apart, and at each station a series...... with a hydrographic front generated where the pycnocline meets the sea-bottom. An internal wave of pronounced amplitude interacts with the shelf slope at ca. 300 m bottom depth, and findings indicated another zone of enhanced abundance in this area. Analysis of the relative abundances of fish larvae within families... South Africa has committed to address freshwater conservation at the catchment scale, using a combination of landscape-level and species-level features as surrogates of freshwater biodiversity. Here we examined fishes in the Olifants catchment, where multiple anthropogenic pressu... Boyle, M D; Ebert, D A; Cailliet, G M In this study, fishes and invertebrates collected from the continental slope (1000 m) of the eastern North Pacific Ocean were analysed using stable-isotope analysis (SIA). Resulting trophic positions (T(P) ) were compared to known diets and habitats from the literature. Dual isotope plots indicated that most species groups (invertebrates and fishes) sorted as expected along the carbon and nitrogen axes, with less intraspecific variability than interspecific variability. Results also indicated an isotopically distinct benthic and pelagic food web, as the benthic food web was more enriched in both nitrogen and carbon isotopes. Trophic positions from SIA supported this finding, resulting in the assignment of fishes to different trophic positions from those expected based on published dietary information. These differences can be explained largely by the habitat of the prey and the percentage of the diet that was scavenged. A mixing model estimated dietary contributions of prey similar to those of the known diet of Bathyraja trachura from stomach-content analysis (SCA). Linear regressions indicated that trophic positions calculated from SIA and SCA, when plotted against B. trachura total length for 32 individuals, exhibited similar variation and patterns. Only the T(P) from SCA yielded significant results (stomach content: P 0·05). © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles. Simon Van Wynsberge Full Text Available Species check-lists are helpful to establish Marine Protected Areas (MPAs and protect local richness, endemicity, rarity, and biodiversity in general. However, such exhaustive taxonomic lists (i.e., true surrogate of biodiversity require extensive and expensive censuses, and the use of estimator surrogates (e.g., habitats is an appealing alternative. In truth, surrogate effectiveness appears from the literature highly variable both in marine and terrestrial ecosystems, making it difficult to provide practical recommendations for managers. Here, we evaluate how the biodiversity reference data set and its inherent bias can influence effectiveness. Specifically, we defined habitats by geomorphology, rugosity, and benthic cover and architecture criteria, and mapped them with satellite images for a New-Caledonian site. Fish taxonomic and functional lists were elaborated from Underwater Visual Censuses, stratified according to geomorphology and exposure. We then tested if MPA networks designed to maximize habitat richness, diversity and rarity could also effectively maximize fish richness, diversity, and rarity. Effectiveness appeared highly sensitive to the fish census design itself, in relation to the type of habitat map used and the scale of analysis. Spatial distribution of habitats (estimator surrogate's distribution, quantity and location of fish census stations (target surrogate's sampling, and random processes in the MPA design all affected effectiveness to the point that one small change in the data set could lead to opposite conclusions. We suggest that previous conclusions on surrogacy effectiveness, either positive or negative, marine or terrestrial, should be considered with caution, except in instances where very dense data sets were used without pseudo-replication. Although this does not rule out the validity of using surrogates of species lists for conservation planning, the critical joint examination of both target and estimator Jurajda, Pavel; Slavík, O.; White, S.M.; Adámek, Zdeněk Roč. 644, č. 1 (2010), s. 89-101 ISSN 0018-8158 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : 0+ Fish * Water Framework Directive * Rivers * Biological quality element Subject RIV: EH - Ecology, Behaviour Impact factor: 1.964, year: 2010 Full Text Available The life history characteristics of some elasmobranchs make them particularly vulnerable to fishing mortality; about a third of all species are listed by the IUCN as Threatened or Near Threatened. Marine Protected Areas (MPAs have been suggested as a tool for conservation of elasmobranchs, but they are likely to be effective only if such populations respond to fishing impacts at spatial-scales corresponding to MPA size. Using the example of the Celtic Sea, we modelled elasmobranch biomass (kg h(-1 in fisheries-independent survey hauls as a function of environmental variables and 'local' (within 20 km radius fishing effort (h y(-1 recorded from Vessel Monitoring Systems data. Model selection using AIC suggested strongest support for linear mixed effects models in which the variables (i fishing effort, (ii geographic location and (iii demersal fish assemblage had approximately equal importance in explaining elasmobranch biomass. In the eastern Celtic Sea, sampling sites that occurred in the lowest 10% of the observed fishing effort range recorded 10 species of elasmobranch including the critically endangered Dipturus spp. The most intensely fished 10% of sites had only three elasmobranch species, with two IUCN listed as Least Concern. Our results suggest that stable spatial heterogeneity in fishing effort creates de facto refugia for elasmobranchs in the Celtic Sea. However, changes in the present fisheries management regime could impair the refuge effect by changing fisher's behaviour and displacing effort into these areas. Ulrich, Clara; Vermard, Youen; Dolder, Paul J. . An objective method is suggested that provides an optimal set of fishing mortality within the range, minimizing the risk of total allowable catch mismatches among stocks captured within mixed fisheries, and addressing explicitly the trade-offs between the most and least productive stocks........ Recent paths towards operationalizing MSY at the regional scale have suggested the expansion of the concept into a desirable area of “pretty good yield”, implemented through a range around FMSY that would allow for more flexibility in management targets. This article investigates the potential of FMSY...... ranges to combine long-term single-stock targets with flexible, short-term, mixed-fisheries management requirements applied to the main North Sea demersal stocks. It is shown that sustained fishing at the upper bound of the range may lead to unacceptable risks when technical interactions occur... Dukerschein, J.T.; Bartels, A.D.; Ickes, B.S.; Pearson, M.S. We applied an Index of Biotic Integrity (IBI) used on Wisconsin/Minnesota waters of the upper Mississippi River (UMR) to compare data from two systemic sampling programmes. Ability to use data from multiple sampling programmes could extend spatial and temporal coverage of river assessment and monitoring efforts. We normalized for effort and tested fish community data collected by the Environmental Monitoring and Assessment Program-Great Rivers Ecosystems (EMAP-GRE) 2004–2006 and the Long Term Resource Monitoring Program (LTRMP) 1993–2006. Each programme used daytime electrofishing along main channel borders but with some methodological and design differences. EMAP-GRE, designed for baseline and, eventually, compliance monitoring, used a probabilistic, continuous design. LTRMP, designed primarily for baseline and trend monitoring, used a stratified random design in five discrete study reaches. Analysis of similarity indicated no significant difference between EMAP-GRE and LTRMP IBI scores (n=238; Global R= 0.052; significance level=0.972). Both datasets distinguished clear differences only between 'Fair' and 'Poor' condition categories, potentially supporting a 'pass–fail' assessment strategy. Thirteen years of LTRMP data demonstrated stable IBI scores through time in four of five reaches sampled. LTRMP and EMAPGRE IBI scores correlated along the UMR's upstream to downstream gradient (df [3, 25]; F=1.61; p=0.22). A decline in IBI scores from upstream to downstream was consistent with UMR fish community studies and a previous, empirically modelled human disturbance gradient. Comparability between EMAP-GRE (best upstream to downstream coverage) and LTRMP data (best coverage over time and across the floodplain) supports a next step of developing and testing a systemic, multi-metric fish index on the UMR that both approaches could inform. Full Text Available The goal of this study was to provide the first scientific data of the intertidal ichthyofauna community of Peniche. In order to have an accurate assessment, anesthetics were used, since this method is more effective than visual census. Therefore, the ideal concentration of clove oil to be used as anesthetics for local rock pool fish was tested. Through laboratory experiments with some of the most common species in the area, the concentration 30 mg.L-1was considered ideal. A total of 4 rockpools were sampled between May and July 2012, in two different locations (2 in Praia da Gamboa and 2 in Portinho da Areia Norte, in Peniche (West of Portugal. A total of 508 fishes belonging to 17 different species were registered. Fish abundance, occurrence frequencies and sizes were registered and compared for the two beaches and for the respective tide pools. The most abundant species was Gobius n.sp. while the most frequent was Gobius paganellus. These two species represent 59.1% of all captured species. Praia da Gamboa was the location with the highest abundance of individuals while Portinho da Areia Norte was the location where larger individuals were collected. It was observed that the size of rockpools affects abundance and density of individuals. Substrate, number and type of shelters also affect density, abundance and the mean size of individuals. Considering the studies focusing on intertidal ichthyofauna worldwide are relatively scarce, and being this ecosystem absolutely crucial both for biological but also socio-economic reasons worldwide, a better understanding of this unique ecosystem is mandatory, so it is possible to understand it, in order to preserve it. Paulo R. Medeiros Full Text Available In recent years, many studies investigated how density-dependent factors, such as shortages in microhabitat and food availability influence the structure of reef fish assemblages. Most of what is currently known, however, comes from comparisons of isolated patch reefs and from correlations between fish abundance and one or few microhabitat variables. In addition, most studies were done in the Caribbean and Indo-Pacific regions, whereas the South Atlantic region has been, to date, understudied. The present study evaluated spatial and temporal variations in reef fish abundance and species richness in a continuous rocky reef and adjacent unconsolidated habitats in a Southwestern Atlantic reef, using underwater techniques to assess both fish numbers and microhabitat variables (depth, rugosity, number of crevices and percent cover of live benthic organisms, bare rock, sand, and limestone. Higher species richness was observed at consolidated substratum stations on both sampling periods (May and October, but fish abundance did not show a significant spatial variation. Topographical complexity and percent cover of algae (except coralline algae were amongst the most important determinants of species richness, and correlations between fish size and refuge crevice size were observed. The non-random patterns of spatial variation in species richness, and to a lesser extent, fish abundance, were related to differences in substratum characteristics and the inherent characteristics of fishes (i.e. habitat preferences and not to geographical barriers restraining fish movement. This study highlights the importance of concomitantly assessing several microhabitat variables to determine their relative influence in reef fish assemblages.Em anos recentes, vários estudos investigaram como os fatores dependentes da densidade, por exemplo, a diminuição na disponibilidade de microhabitats e alimento, influenciam a estrutura das assembleias de peixes. A maior parte do Full Text Available Metacommunity nestedness can be affected by both idiosyncratic species and species turnover, and diversity partitioning allows one to separate turnover and nested components within β-diversity. Thus, complimentary analysis of metacommunity nestedness and diversity partitioning allows for the identification of the underlying changes at both local and regional scales. We examined changes of fish assemblages in metacommunity nestedness and α-, β-, and γ-diversities resulting from the intense loss of native species and the invasion of nonnative species in Chinese highland lakes over the past 60 years. We found metacommunity nestedness rose markedly over time, following the loss of both β- and γ-diversity resulting from the loss of native species, and the increase of α diversity by the addition of nonnative species. This pattern is contradictory to the selective extinction leading to larger nestedness in natural ecosystems and indicates the human-induced negative effects on the metacommunity. However, β-diversity partitioning showed that the turnover component due to species replacement among lakes still contributes more than the nested component, suggesting the importance of avoiding setting conservation priorities based exclusively on metacommunity nestedness theory, but taking a more holistic metacommunity-approach to conservation instead. Full Text Available Sciaenids are fish which are normally abundant in tropical estuaries of the western Atlantic. Studies on the Caeté river estuary in the northern Brazilian state of Pará have revealed that in this area Sciaenidae is the dominant family, comprising almost 50% of all teleosts sampled. In this paper we present the results of the first phylogenetic study on South American estuarine sciaenids, during which we obtained mitochondrial gene 16S sequences from 15 species belonging to eight genera occurring in the Caeté estuary. Intergeneric nucleotide divergences varied from 5 to 15%, Lonchurus and Menticirrhus being the most divergent lineages. Nucleotide divergences were quite variable amongst species of the same genus, ranging from 1.2% (Stellifer microps x Stellifer naso to 8.4% (Menticirrhus americanus x Menticirrhus littoralis. Cladograms based on maximum parsimony, minimum evolution and maximum likelihood depicted an explosive diversification pattern for the western Atlantic sciaenid assemblage. Our analysis further reveals a very close relationship between Bairdiella and Stellifer, a monophyletic clade which emerged during the more recent diversification events of the Sciaenidae family. The phylogenetic reconstruction suggests the need for a revision of the taxonomy and nomenclature of the Bairdiella/Stellifer group. Full Text Available The ecomorphology of 14 fish species resident in a headwater riffles area of the São Francisco river, southeastern Brasil, was analyzed and combined with diet and feeding behavior data, previously obtained by us. The three larger species groups formed in the ecomorphological analysis were found to reflect primarily microhabitat occupation in the following manner: a nektonic characids with compressed bodies, lateral eyes and lateral pectoral fins, with diurnal and opportunistic feeding habits (Astyanax rivularis, Bryconamericus stramineus, and Bryconamericus sp.; b nektobenthic characiforms and siluriforms with fusiform bodies and expanded pectoral fins, including sit-and-wait characidiins, predators of aquatic insect larvae (Characidium fasciatum and Ch.zebra, as well as the algae grazing parodontids (Apareiodon ibitiensis and Parodon hilarii, and also the heptapterid and trichomycterid catfishes that practice substrate speculation and feed on benthic aquatic insect larvae (Cetopsorhamdia iheringi, Imparfinis minutus, Rhamdia quelen, and Trichomycterus sp.; c benthic species with depressed bodies, suctorial oral discs, dorsal eyes, and horizontal pectoral fins, represented by the periphytivorous loricariid catfishes (Hisonotus sp., Harttia sp., and Hypostomus garmani. Correlation between diet and general morphology was not significant in our analysis, unless when the analyzed set included only nektonic and benthic species, indicating that the lack of correlation between these factors is most pronounced in the group of nektobenthic species. The unequivocal case of morphological convergence found between the nektobenthic Characidiinae and Parodontidae is a clear example of the integration between phylogenetic information and ecomorphology, and provides a way to objectively identify cases of morphological and adaptive convergence and divergence. Furthermore, the general congruence between the ecomorphological results and the independently obtained Henrique Corrêa Giacomini Full Text Available The lakes in the middle rio Doce Valley (MG are suffering impacts due to the introduction of invasive fish species, mainly piscivorous species like red piranha Pygocentrus nattereri and peacock bass Cichla kelberi. Fishes were collected in bimonthly samples conducted at ten lakes along a year. The present study showed that the composition of native fish assemblages is significantly related to the presence and type of non-native species. Fish species distribution among lakes can be explained by differences in species body size: smaller native species are less concentrated in lakes with invasive piscivores, which is in accordance with the hypothesis that they have greater susceptibility to predation by invaders. Another probable cause for this correlation is the proximity of lakes to the drainage system, which could explain both the non-native incidence and the turnover of native species composition. Furthermore, temporal variability in species composition was significantly higher in invaded lakes. This last factor may be linked to seasonal flood pulses, which carry immigrant fishes from streams in the vicinity. The metacommunity framework can bring insights for future studies in such spatially structured systems, and the approach should improve our understanding of processes underlying species composition as well as help direct conservation-focused management plans.Os lagos do Vale do médio rio Doce (MG têm sofrido impactos devido à introdução de espécies invasoras de peixes, principalmente de espécies piscívoras como a piranha Pygocentrus nattereri e o tucunaré Cichla kelberi. Peixes foram coletados em seis amostragens bimestrais durante um ano. O presente trabalho demonstrou que a composição das assembleias de peixes nativos está significativamente relacionada à presença e ao tipo de espécies não nativas. A distribuição de espécies entre os lagos pode ser explicada por diferenças no tamanho corporal: espécies nativas de Alan M. Friedlander Full Text Available Fishes at Isla del Coco National Park, Costa Rica, were surveyed as part of a larger scientific expedition to the area in September 2009. The average total biomass of nearshore fishes was 7.8 tonnes per ha, among the largest observed in the tropics, with apex predators such as sharks, jacks, and groupers accounting for nearly 40% of the total biomass. The abundance of reef and pelagic sharks, particularly large aggregations of threatened species such as the scalloped hammerhead shark (up to 42 hammerheads ha-1 and large schools of jacks and snappers show the capacity for high biomass in unfished ecosystems in the Eastern Tropical Pacific. However, the abundance of hammerhead and reef whitetip sharks appears to have been declining since the late 1990s, and likely causes may include increasing fishing pressure on sharks in the region and illegal fishing inside the Park. One Galapagos shark tagged on September 20, 2009 in the Isla del Coco National Park moved 255km southeast towards Malpelo Island in Colombia, when it stopped transmitting. These results contribute to the evidence that sharks conduct large-scale movements between marine protected areas (Isla del Coco, Malpelo, Galápagos in the Eastern tropical Pacific and emphasize the need for regional-scale management. More than half of the species and 90% of the individuals observed were endemic to the tropical eastern Pacific. These high biomass and endemicity values highlight the uniqueness of the fish assemblage at Isla del Coco and its importance as a global biodiversity hotspot.La biomasa promedio de peces costeros en el Parque Nacional Isla del Coco en septiembre de 2010 fue de 7,8 toneladas por hectárea, entre las más elevadas halladas jamás en zonas tropicales. Los grandes depredadores representaron el 40% de la biomasa total. La abundancia de tiburones costeros y pelágicos, particularmente las enormes agregaciones de tiburón martillo (hasta 42 individuos por hectárea y los The aim of this study was to determine (i) the importance of riverine and marine organic matter for the Thukela Bank food web; and (ii) whether there are seasonal changes in the Thukela River stable isotope values, and, if so, whether these are reflected in the isotope values of demersal organisms. Estuarine organic matter ... Full Text Available Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries, a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1 spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2 an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3 a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in Russo, Tommaso; Parisi, Antonio; Garofalo, Germana; Gristina, Michele; Cataudella, Stefano; Fiorentino, Fabio Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries), a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1) spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2) an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3) a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in the Strait of Ulrich, Clara; Reeves, Stuart A.; Vermard, Youen be exhausted before the TAC of another, leading to catches of valuable fish that cannot be landed legally. This important issue is, however, usually not quantified and not accounted for in traditional management advice. A simple approach using traditional catch and effort information was developed, estimating...... catch potentials for distinct fleets (groups of vessels) and métiers (type of activity), and hence quantifying the risks of over- and underquota utilization for the various stocks. This method, named Fcube (Fleet and Fisheries Forecast), was applied successfully to international demersal fisheries...... other stocks and corresponding effort reductions are applied.... Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Michael a different approach using the gear itself (design and dimensions) for understanding and estimation of the physical interactions with the seafloor at the individual fishing operation level. With reference to the métier groupings of EU logbooks, we defined 17 distinct towed gear groups in European waters (11...... otter trawl groups, 3 beam trawl groups, 2 demersal seine groups, and 1 dredge group), for which we established seafloor “footprints”. The footprint of a gear was defined as the relative contribution from individual larger gear components, such as the trawl doors, sweeps and ground gear, to the total...... types based on a review of the scientific literature. For each defined gear group a vessel-size (kW or total length) – gear size (total gear width or circumference) relationship was estimated to enable the prediction of gear footprint area and sediment penetration from vessel size. The implications... Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Mike such as logbook data. Here, we take a different approach starting from the gear itself (design and dimensions) to estimate the physical interactions with the seabed at the level of the individual fishing operation. We defined 14 distinct towed gear groups in European waters (eight otter trawl groups, three beam...... trawl groups, two demersal seine groups, and one dredge group), for which we established gear “footprints”. The footprint of a gear is defined as the relative contribution from individual larger gear components, such as trawl doors, sweeps, and groundgear, to the total area and severity of the gear...... to enable the prediction of gear footprint area and sediment penetration from vessel size. Application of these relationships with average vessel sizes and towing speeds provided hourly swept-area estimates by métier. Scottish seining has the largest overall gear footprint of ∼1.6 km2 h−1 of which 0.08 km2... Marchal, P.; Ulrich, C.; Pastoors, M. The scope of this study is to investigate the extent to which area-based management may have influenced the fishing efficiency of the Danish and Dutch demersal fleets harvesting cod, plaice and sole in the North Sea. Special consideration is given to the `plaice box', a restricted area where fishing David Robert Cole Full Text Available This paper contends that the power of Deleuze & Guattari’s (1988 notion of assemblage as theorised in 1000 Plateaus can be normalised and reductive with reference to its application to any social-cultural context where an open system of dynamic and fluid elements are located. Rather than determining the assemblage in this way, this paper argues for an alternative conception of ‘strange assemblage’ that must be deliberately and consciously created through rigorous and focused intellectual, creative and philosophical work around what makes assemblages singular. The paper will proceed with examples of ‘strange assemblage’ taken from a film by Peter Greenaway (A Zed and 2 Noughts; the film ‘Performance’; educational research with Sudanese families in Australia; the book, Bomb Culture by Jeff Nuttall (1970; and the band Hawkwind. Fittingly, these elements are themselves chosen to demonstrate the concept of ‘strange assemblage’, and how it can be presented. How exactly the elements of a ‘strange assemblage’ come together and work in the world is unknown until they are specifically elaborated and created ‘in the moment’. Such spontaneous methodology reminds us of the 1960s ‘Happenings’, the Situationist International and Dada/Surrealism. The difference that will be opened up by this paper is that all elements of this ‘strange assemblage’ cohere in terms of a rendering of ‘the unacceptable.' Ana Cristina Petry Full Text Available The effects of the duration of the floods on abiotic variables and attributes of species tolerant and intolerant to hypoxia (STH and SIH respectively were evaluated in rivers and lakes of the upper Paraná River. Fish were sampled once a year, in six sampling stations, during the high water period from 2000 to 2003. There were overall reductions in dissolved oxygen levels and increases in transparency of water in lakes in years of moderate floods. The duration of floods influenced species differentially based on their tolerance to hypoxia: in moderate floods, richness of STH increased and numerical abundance and biomass of SIH reduced significantly. Opposite relationships were detected between dissolved oxygen and the attributes of STH and SIH. Dissolved oxygen was the best predictor of variability of STH and SIH in years of moderate floods, whereas water transparency predicted significant amounts of STH in years of short floods. Being positively affected by dissolved oxygen reductions, STH seem to take advantages in persisting in seasonally harsh lentic habitats. The incorporation of abiotic data as well the differential tolerance of species to hypoxia would improve further investigations of the effects of interannual variations in the flood pulse on tropical fish assemblagesOs efeitos da duração da cheia sobre algumas variáveis abióticas e atributos das assembleias de peixes (espécies tolerantes e intolerantes à hipóxia, STH e SIH, respectivamente foram avaliados em rios e lagoas do alto rio Paraná. Os peixes foram amostrados uma vez ao ano, em seis localidades, durante o período de águas altas entre 2000 e 2003. Houve reduções generalizadas nos níveis de oxigênio dissolvido e aumentos na transparência da água em lagos em anos de cheias moderadas. A duração das cheias influenciou as espécies diferencialmente em função de sua tolerância à hipóxia: em anos de cheias moderadas, a riqueza das STH aumentou e a abund This research is intended to apply geostatistical analysis in fish abundance estimation in the north Java waters. Geostatistical is a series of methods to examine one or more spatially distributed variables through structure analysis of the data. Trawl data obtained using the bottom trawl operated by Bawal Putih vessel. Data processing includes the standardization of catch, geographic position transformation to UTM format, variogram model fitting and abundance prediction using the model. Analysis of trawl data structure was done by using geostatistical analysis, estimation results of the experimental semi-variogram were then used to infer the characteristics of demersal fish abundance in the north of central Java waters. Results of structural analysis and models fitting using geostatistical analysis showed that the most suitable model with all data used were spherical model with different parameters from each model. The models are then used to estimate the value of fish abundance on the points that there is no abundance information through kriging interpolation process. Results of cross-validation of the estimated abundance using kriging with actual values shows that R2 values varied for each data set. Geostatistical prediction results showed smaller coefficients of variation compare to arithmetic calculations. Hemery, Lenaïg G.; Henkel, Sarah K.; Cochrane, Guy R. Environmental assessment studies are usually required by a country's administration before issuing permits for any industrial activities. One of the goals of such environmental assessment studies is to highlight species assemblages and habitat composition that could make the targeted area unique. A section of the Oregon continental slope that had not been previously explored was targeted for the deployment of floating wind turbines. We carried out an underwater video survey, using a towed camera sled, to describe its benthic assemblages. Organisms were identified to the lowest taxonomic level possible and assemblages described related to the nature of the seafloor and the depth. We highlighted six invertebrate assemblages and three fish assemblages. For the invertebrates within flat soft sediments areas we defined three different assemblages based on primarily depth: a broad mid-depth (98–315 m) assemblage dominated by red octopus, sea pens and pink shrimps; a narrower mid-depth (250–270 m) assemblage dominated by box crabs and various other invertebrates; and a deeper (310–600 m) assemblage dominated by sea urchins, sea anemones, various snails and zoroasterid sea stars. The invertebrates on mixed sediments also were divided into three different assemblages: a shallow (~100 m deep) assemblage dominated by plumose sea anemones, broad mid-depth (170–370 m) assemblage dominated by sea cucumbers and various other invertebrates; and, again, a narrower mid-depth (230–270 m) assemblage, dominated by crinoids and encrusting invertebrates. For the fish, we identified a rockfish assemblage on coarse mixed sediments at 170–370 m and another fish assemblage on smaller mixed sediments within that depth range (250–370 m) dominated by thornyheads, poachers and flatfishes; and we identified a wide depth-range (98–600 m) fish assemblage on flat soft sediments dominated by flatfishes, eelpouts and thornyheads. Three of these assemblages (the two Hemery, Lenaïg G.; Henkel, Sarah K.; Cochrane, Guy R. Environmental assessment studies are usually required by a country's administration before issuing permits for any industrial activities. One of the goals of such environmental assessment studies is to highlight species assemblages and habitat composition that could make the targeted area unique. A section of the Oregon continental slope that had not been previously explored was targeted for the deployment of floating wind turbines. We carried out an underwater video survey, using a towed camera sled, to describe its benthic assemblages. Organisms were identified to the lowest taxonomic level possible and assemblages described related to the nature of the seafloor and the depth. We highlighted six invertebrate assemblages and three fish assemblages. For the invertebrates within flat soft sediments areas we defined three different assemblages based on primarily depth: a broad mid-depth (98-315 m) assemblage dominated by red octopus, sea pens and pink shrimps; a narrower mid-depth (250-270 m) assemblage dominated by box crabs and various other invertebrates; and a deeper (310-600 m) assemblage dominated by sea urchins, sea anemones, various snails and zoroasterid sea stars. The invertebrates on mixed sediments also were divided into three different assemblages: a shallow ( 100 m deep) assemblage dominated by plumose sea anemones, broad mid-depth (170-370 m) assemblage dominated by sea cucumbers and various other invertebrates; and, again, a narrower mid-depth (230-270 m) assemblage, dominated by crinoids and encrusting invertebrates. For the fish, we identified a rockfish assemblage on coarse mixed sediments at 170-370 m and another fish assemblage on smaller mixed sediments within that depth range (250-370 m) dominated by thornyheads, poachers and flatfishes; and we identified a wide depth-range (98-600 m) fish assemblage on flat soft sediments dominated by flatfishes, eelpouts and thornyheads. Three of these assemblages (the two broad fish assemblages and the deep Hansson, S.; Frid, C.L.J.; Ragnarsson, S.A.; Rijnsdorp, A.; Steingrimsson, S.A. In many coastal areas fishing constitutes the dominant anthropogenic impact on coastal ecosystems. That fishing has altered the abundance and size spectra of fish communities is beyond doubt. We use time series of the abundance, in the North Sea, of 8 demersal fish species and data on food Mindel, Beth L; Neat, Francis C; Trueman, Clive N; Webb, Thomas J; Blanchard, Julia L Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300-2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf. Beth L. Mindel Full Text Available Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300–2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf. Sutton, T. T.; Porteiro, F. M.; Heino, M.; Byrkjedal, I.; Langhelle, G.; Anderson, C. I. H.; Horne, J.; Søiland, H.; Falkenhaug, T.; Godø, O. R.; Bergstad, O. A. The assemblage structure and vertical distribution of deep-pelagic fishes relative to a mid-ocean ridge system are described from an acoustic and discrete-depth trawling survey conducted as part of the international Census of Marine Life field project MAR-ECO . The 36-station, zig-zag survey along the northern Mid-Atlantic Ridge (MAR; Iceland to the Azores) covered the full depth range (0 to >3000 m), from the surface to near the bottom, using a combination of gear types to gain a more comprehensive understanding of the pelagic fauna. Abundance per volume of deep-pelagic fishes was highest in the epipelagic zone and within the benthic boundary layer (BBL; 0-200 m above the seafloor). Minimum fish abundance occurred at depths below 2300 m but above the BBL. Biomass per volume of deep-pelagic fishes over the MAR reached a maximum within the BBL, revealing a previously unknown topographic association of a bathypelagic fish assemblage with a mid-ocean ridge system. With the exception of the BBL, biomass per volume reached a water column maximum in the bathypelagic zone between 1500 and 2300 m. This stands in stark contrast to the general "open-ocean" paradigm that biomass decreases exponentially from the surface downwards. As much of the summit of the MAR extends into this depth layer, a likely explanation for this mid-water maximum is ridge association. Multivariate statistical analyses suggest that the dominant component of deep-pelagic fish biomass over the northern MAR was a wide-ranging bathypelagic assemblage that was remarkably consistent along the length of the ridge from Iceland to the Azores. Integrating these results with those of previous studies in oceanic ecosystems, there appears to be adequate evidence to conclude that special hydrodynamic and biotic features of mid-ocean ridge systems cause changes in the ecological structure of deep-pelagic fish assemblages relative to those at the same depths over abyssal plains. Lacking terrigenous input of Marty, G.D.; Okihiro, M.S.; Hanes, D. Demersal rockfish are the only fish species that have been found dead in significant numbers after major oil spills, but the link between oil exposure and effect has not been well established. After the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska, several species of rockfish (Sebastes spp.) from oiled and reference sites were analyzed for hydrocarbon metabolites in bile (1989-1991) and for microscopic lesions (1990 and 1991). Biliary hydrocarbons consistent with exposure to Exxon Valdez oil were elevated in 1989, but not in 1990 or 1991. Significant microscopic findings included pigmented macrophage aggregates and hepatic megalocytosis, fibrosis, and lipid accumulation. Site differences in microscopic findings were significant with respect to previous oil exposure in 1991 (P=0.038), but not in 1990. However, differences in microscopic findings were highly significant with respect to age and species in both years (P<0.001). We concluded that demersal rockfish were exposed to Exxon Valdez oil in 1989, but differences in microscopic changes in 1990 and 1991 were related more to age and species differences than to previous oil exposure. (author) Jurajda, Pavel; Adámek, Zdeněk; Janáč, Michal; Valová, Zdenka Roč. 55, č. 3 (2010), s. 123-136 ISSN 1212-1819 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish community * macroinvertebrates * pollution * channelization * Elbe basin Subject RIV: GL - Fishing Impact factor: 1.190, year: 2010 http://www.agriculturejournals.cz/publicFiles/17674.pdf Mesohabitats, fish assemblage composition, and mesohabitat use of the Rio Grande silvery minnow over a range of seasonal flow regimes in the Rio Grande/Rio Bravo del Norte, in and near Big Bend National Park, Texas, 2010-11 Moring, J. Bruce; Braun, Christopher L.; Pearson, Daniel K. In 2010–11, the U.S. Geological Survey (USGS), in cooperation with the U.S. Fish and Wildlife Service, evaluated the physical characteristics and fish assemblage composition of mapped river mesohabitats at four sites on the Rio Grande/Rio Bravo del Norte (hereinafter Rio Grande) in and near Big Bend National Park, Texas. The four sites used for the river habitat study were colocated with sites where the U.S. Fish and Wildlife Service has implemented an experimental reintroduction of the Rio Grande silvery minnow (Hybognathus amarus), a federally listed endangered species, into part of the historical range of this species. The four sites from upstream to downstream are USGS station 08374340 Rio Grande at Contrabando Canyon near Lajitas, Tex. (hereinafter the Contrabando site), USGS station 290956103363600 Rio Grande at Santa Elena Canyon, Big Bend National Park, Tex. (hereinafter the Santa Elena site), USGS station 291046102573900 Rio Grande near Ranger Station at Rio Grande Village, Tex. (hereinafter the Rio Grande Village site), and USGS station 292354102491100 Rio Grande above Stillwell Crossing near Big Bend National Park, Tex. (hereinafter the Stillwell Crossing site). Thresher, R E Eggs of demersal spawning coral-reef fishes of the tropical western Atlantic are smaller than those of related species in the western Pacific. Decreased egg volume may result in increased fecundity per unit body weight of Atlantic species, a factor that may underlie apparent differences in the stability of the respective coral-reef fish communities. Strydom, Nadine A.; d'Hotman, Bruce D. Larval fishes were collected in the Cape Padrone surf zone on the southeast coast of South Africa, using a modified small-mesh seine net. The aim of the study was to assess the composition of fish larvae, with respect to their association with estuaries, in a surf zone that was not in close proximity to an estuary (>5 km). Sampling took place bimonthly during diurnal spring low tides between March and July 2003. In total, 544 fish were caught in the surf zone, comprising 14 families represented by 19 positively identified species, as well as an additional two species that were differentiated but remain unidentified. The families Mugilidae (65%) and Sparidae (26%) dominated the larval catch. The majority of larval fishes caught were in the postflexion stage of development, although some early juveniles were also caught. Body lengths of fish larvae ranged between 2 and 28 mm, with the majority of larvae at the recruitment size for the species. A high proportion of the fish species caught were estuary-dependent. Estuary-dependent marine fish larvae (categories I, II and IV) comprised 68% of total catch by species and 98% by number of individuals. Exclusively marine species (category III) were encountered in low numbers in the surf. The present study provides evidence for continuity in temperate South African surf zones in terms of domination by estuary-dependent larvae and reasons for this pattern are discussed. Noack, Thomas; Eggers, Florian; Frandsen, Rikke of the total landings where the seine fleet and catches are decreasing. The Danish seine is a specific type of encircling net to catch demersal fish. It is characterized by moderate fuel consumption and no use of heavy weights or doors, probably resulting in a relatively gentle bottom-contact and low... National Oceanic and Atmospheric Administration, Department of Commerce — During 1990-1999, coral growth and fish abundance were monitored at stations located at and in the vicinity of the Waianae Ocean Outfall. Comparisons of results with... National Oceanic and Atmospheric Administration, Department of Commerce — During 1990-1999, coral growth and fish abundance were monitored at stations located at and in the vicinity of the Waianae Ocean Outfall. Comparisons of results with... Plass-Johnson, Jeremiah Grahm; Teichberg, Mirta; Bednarz, Vanessa N. The Spermonde Archipelago is a complex of ~70 mostly populated islands off Southwest Sulawesi, Indonesia, in the center of the Coral Triangle. The reefs in this area are exposed to a high level of anthropogenic disturbances. Previous studies have shown that variation in the benthos is strongly...... with distance, while few species were present across the entire range of sites. Relating fish communities to benthic composition using a multivariate generalized linear model confirmed that fish groups relate to structural complexity (rugosity) or differing benthic groups; either algae, reef builders (coral...... and crustose coralline algae) or invertebrates and rubble. From these relationships we can identify sets of fish species that may be lost given continued degradation of the Spermonde reefs. Lastly, the incorporation of water quality, benthic and fish indices indicates that local coral reefs responded... Claudet, Joachim; Pelletier, Dominique; Jouvenel, J.y; Bachet, F; Galzin, R Marine protected areas (MPAs) are increasingly envisaged as a tool to manage coastal ecosystems and fisheries. Assessment of their performance with respect to management objectives is therefore important. A number of WAS provided conservation benefits for fished species. Observed benefits do not apply to all species at all times, and responses to protection are also highly variable among fish taxa. Among the many empirical studies on marine reserves, only a few designs considered 'before and ... Dettai, Agnes; Adamowizc, Sarah J.; Allcock, Louise; Arango, Claudia P.; Barnes, David K. A.; Barratt, Iain; Chenuil, Anne; Couloux, Arnaud; Cruaud, Corinne; David, Bruno; Denis, Françoise; Denys, Gael; Díaz, Angie; Eléaume, Marc; Féral, Jean-Pierre; Froger, Aurélie; Gallut, Cyril; Grant, Rachel; Griffiths, Huw J.; Held, Christoph; Hemery, Lenaïg G.; Hosie, Graham; Kuklinski, Piotr; Lecointre, Guillaume; Linse, Katrin; Lozouet, Pierre; Mah, Christopher; Monniot, Françoise; Norman, Mark D.; O'Hara, Timothy; Ozouf-Costaz, Catherine; Piedallu, Claire; Pierrat, Benjamin; Poulin, Elie; Puillandre, Nicolas; Riddle, Martin; Samadi, Sarah; Saucède, Thomas; Schubart, Christoph; Smith, Peter J.; Stevens, Darren W.; Steinke, Dirk; Strugnell, Jan M.; Tarnowska, K.; Wadley, Victoria; Ameziane, Nadia The Dumont d’Urville Sea (East Antarctic region) has been less investigated for DNA barcoding and molecular taxonomy than other parts of the Southern Ocean, such as the Ross Sea and the Antarctic Peninsula. The Collaborative East Antarctic MARine Census (CEAMARC) took place in this area during the austral summer of 2007-2008. The Australian vessel RSV Aurora Australis collected very diverse samples of demersal and benthic organisms. The specimens were sorted centrally, and then distributed to taxonomic experts for molecular and morphological taxonomy and identification, especially barcoding. The COI sequences generated from CEAMARC material provide a sizeable proportion of the Census of Antarctic Marine Life barcodes although the studies are still ongoing, and represent the only source of sequences for a number of species. Barcoding appears to be a valuable method for identification within most groups, despite low divergences and haplotype sharing in a few species, and it is also useful as a preliminary taxonomic exploration method. Several new species are being described. CEAMARC samples have already provided new material for phylogeographic and phylogenetic studies in cephalopods, pycnogonids, teleost fish, crinoids and sea urchins, helping these studies to provide a better insight in the patterns of evolution in the Southern Ocean. Ecological relations between fish assemblages and their habitats in the Elbe River (ELFI). Final report; Oekologische Zusammenhaenge zwischen Fischgemeinschafts- und Lebensraumstrukturen der Elbe (ELFI). Abschlussbericht Nellen, W.; Kausch, H.; Thiel, R.; Ginter, R. (eds.) In the framework of the joint project, extensive data were obtained with regard to ecomorphology and hydro-dynamics of fish habitats, species diversity, age structure, abundance, habitat quality, habitat use, larval drift, migrations, growth, health status and population genetics of the fish fauna of the middle Elbe River. The data were stored in data banks and were used as basis to assess the middle Elbe River, to formulate a fish-ecological guiding view, and to develop predictive habitat models for different life stages of indicatory fish species. The data and results of the joint project will be stored in fish data banks of the ARGE Elbe and of the Federal Institute of Hydrology. The information is useful for the development of decision support systems. (orig.) [German] Im Rahmen des Verbundprojekts wurden umfangreiche Daten zu Oekomorphologie und Hydrodynamik von Fischhabitaten, zu Artendiversitaet, Altersstruktur, Abundanz, Habitatqualitaet und -nutzung, Larvendrift, Wanderungen, Wachstum, Gesundheitsstatus und Populationsgenetik der Fischfauna in der Mittelelbe erhoben und in Datenbanken abgelegt. Darauf aufbauend wurde die Mittelelbe fischoekologisch bewertet, ein fischoekologisches Leitbild formuliert und prognosefaehige Habitatmodelle fuer verschiedene Lebensstadien von Indikatorfischarten entwickelt. Die Daten und Ergebnisse des Verbundprojekts fliessen in die Fischdatenbanken der ARGE Elbe und der Bundesanstalt fuer Gewaesserkunde ein und stehen fuer die Entwicklung von DSS (Decision Support Systems) zur Verfuegung. (orig.) Reiss, H.; Greenstreet, S.P.R.; Sieben, K.; Ehrich, S.; Piet, G.J.; Quirijns, F.; Wolff, W.J.; Kroncke, I. Demersal fishing alters seabed habitats and affects the structure and functioning of benthic invertebrate communities. At a critical level of disturbance, such communities may approach an equilibrium disturbed state in which a further increase in disturbance has little additional impact. Such Roč. 72, č. 7 (2008), s. 1815-1824 ISSN 0022-1112 R&D Projects: GA AV ČR IAA6093404 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish-habitat association * resource partitioning * Soudanian River Subject RIV: EH - Ecology, Behaviour Impact factor: 1.246, year: 2008 Adámek, Zdeněk; Zahrádková, S.; Jurajda, Pavel; Bernardová, I.; Jurajdová, Zdenka; Janáč, Michal; Němejcová, D. Roč. 71, č. 3 (2013), s. 93-115 ISSN 1330-061X R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Macrozoobenthos * Fish * Diversity * River pollution * River regulation * Joint Danube Survey Subject RIV: EG - Zoology http://ribarstvo.agr.hr/volumes.php?lang=en&search=Article%3A656 The task of the concise chapter is to describe the Danish experiences with a basic regulation based upon the principle of Transferable Fisheries Concessions, TFC - at the backgruund of the introduction of Transfreable Quotas in 2003 (pelagic fisheries) and 2007 (demersal fisheries). To do this th...... dependent upon the struggles on the financial markets, replacing sustainable fishing methods with heavy buttom trawling and undermining the future of young people in the fishing industry.... Spatio-temporal variability in ontogenetic guild structure of an intertidal fish assemblage in central Chile Variabilidad espacio-temporal en la estructura de gremios ontogenéticos de un ensamble de peces intermareales de Chile central PATRICIA A BERRÍOS Full Text Available Species resource use can vary throughout ontogeny, potentially affecting community dynamics. This can be particularly important for species facing high variability in environmental conditions and going through several orders of magnitude in size, as intertidal fishes. However, the influence of the resulting ontogenetic changes in guild membership on the spatio-temporal structure of fish assemblages remains virtually unknown. Here we assessed the spatial and temporal variability in the ontogenetic feeding guild (OFG structure of the fish assemblage inhabiting the temperate rocky intertidal zone along central Chilean coast. This was done applying principal component analysis (PCA and randomization tests (R-test on the relative OFG composition of fish assemblages, obtained from seasonal samples from ten pools located at two heights in the intertidal zone in three localities between 33° and 34° S. Overall, the PCA and R-tests suggest that spatial variability dominated over temporal variability in OFG structure, mainly due to a higher representation of omnivore species at high intertidal pools in two of the three sampled localities. However, phenology-related changes in the representation of fish size-classes (i.e. carnivore recruitment in spring-summer along with ontogenetic differences in habitat selection (e.g., selection for low intertidal pools by bigger-sized carnivore OFG contributed to both spatial and temporal differentiation in OFG structure. Finally, the relative representation of each OFG correlated with that of their dominant species, without evidence for density compensation. This suggests low levels of functional redundancy among species in each OFG, highlighting the vulnerability of assemblage functioning to size-biased disturbances as fishing.El uso de los recursos puede variar a través de la ontogenia, afectando potencialmente las dinámicas comunitarias. Esto puede ser de particular importancia en especies que enfrentan alta Paulo dos Santos Pompeu Full Text Available In the Neotropics, a large proportion of fish communities of large rivers use floodplain as habitats for feeding, reproduction, and refuge. An evaluation was made of the effects of extended dry periods on the species richness, abundance and local extinction of fish species in three marginal lagoons in the middle São Francisco River, southeastern Brazil. The studied lagoons fail to receive river floods during the study period (1994-1996. A gradual reduction in richness and abundance was observed in all lagoons. Migratory fish species had the highest probability to become extinct in the two lagoons that remained with large water volume. Species tolerant to low levels of dissolved oxygen had the lowest probability of local extinction in the lagoon showing an abrupt reduction in water volume. Similar changes to those observed in the current study are likely to occur in the floodplains if dams would be constructed in this segment of the river. Adequate water releases from Três Marias reservoir, located upstream, should be considered as a management tool for producing episodic flooding on the marginal lagoons of the region. Kantoussan, Justin; Ecoutin, Jean Marc; Simier, Monique; Tito de Morais, Luis; Laë, Raymond The utility of taxonomic and functional approaches in assessing the structure of fish communities is tested in the hypersaline estuary of the Casamance river using data from surveys of commercial fisheries conducted between April and July of 2005. Both taxonomic and functional diversity decrease from downstream to upstream regions of the estuary. In terms of species composition, marine-estuarine species (33.3-46.3%, depending on the site) and estuarine species of marine origin (29.3-41.7%) dominate the exploited population in the Casamance estuary. In contrast, the proportion of strictly estuarine species observed upstream is twice that observed downstream. Quantitative analysis based on biomass landed distinguishes two groups in the population: (1) a group of species that is dominant downstream, containing primarily terminal predators and secondary consumers categorised as marine species that are occasional or accessory in estuaries, estuarine marine species, and estuarine species of marine origin; and (2) a group of species characteristic of the upstream region, dominated by a few species (Sarotherodon melanotheron, Tilapia guineensis, and Mugil cephalus) mainly of strictly estuarine and/or herbivorous categories and Elops lacerta, a carnivore fish. The outcomes of the two approaches are similar, and both indicate that the fish community in this estuary is under the influence of strong environmental disturbance. However, the scales at which the specific and functional approaches most reliably reflect environmental conditions are different. The taxonomic approach, i.e., the use of specific biomass is more appropriate at the ecosystem scale and therefore more accessible to local human communities, whereas the functional approach is better suited to regional and sub-regional studies because of the change in species composition from one environment to another. Pinton, Aurélie; Le Fur, Soizic; Otero, Olga In the fossil record, the quantification of continuous morphological variation has become a central issue when dealing with species identification and speciation. In this context, fossil taxa with living representatives hold great promise, because of the potential to characterise patterns of intraspecific morphological variation in extant species prior to any interpretation in the fossil record. The vast majority of catfish families fulfil this prerequisite, as most of them are represented by extant genera. However, although they constitute a major fish group in terms of distribution, and ecological and taxonomic diversity, the quantitative study of their past morphological variation has been neglected, as fossil specimens are generally identified based on the scarcest remains, that is, complete neurocrania that bear discrete characters. Consequently, a part of freshwater catfish history is unprospected and unknown. In this study, we explored the morphological continuous variation of the humeral plate shape in Synodontis catfishes using Elliptic Fourier Analysis (EFA), and compared extant members and fossil counterparts. We analysed 153 extant specimens of 11 Synodontis species present in the Chad basin, in addition to 23 fossil specimens from the Chadian fossiliferous area of Toros Menalla which is dated around 7 Ma. This highly speciose genus, which is one of the most diversified in Africa, exhibits a rich fossil record with several hundred remains mostly identified as Synodontis sp. The analysis of the outline of the humeral plate reveals that some living morphological types were already represented in the Chad Basin 7 My ago, and allows for the discovery of extinct species. Beside illuminating the complex Neogene evolutionary history of Synodontis, these results underline the interest in the ability of isolated remains to reconstruct a past dynamic history and to validate the relevance of EFA as a tool to explore specific diversity through time. J. Morphol. 277 Full Text Available Over the last 30 years, the Cerrado has been experiencing various antropic impacts that have brought about alterations to species composition, structure and functioning of aquatic habitats. Therefore, studies on negative impacts are useful to prevent future damage and restore environmental quality. The objectives of our study were: i to adapt an index of biotic integrity of streams in the Rio Cuiabá Basin and ii to analyze if the Index of Biotic Integrity (IBI correlated with the environmental quality measured by the Index of Environmental Quality (IEQ and with the mesohabitat structure. We sampled 26 streams in sub-basins of the Cuiabá River. In each stream, we closed a stretch of 50 m with blockage nets and used electrofishing to capture fish. To obtain a measure of environmental quality in sampled units, we characterized the stream and its micro basin. For the analyses, we used the Spearman Correlation, Kruskal-Wallis test and Analysis of Multiple Regression. We collected 697 individuals distributed into 6 orders, 15 families and 49 species. The IBI followed changes on environmental quality measured by IEQ when we removed streams that present natural barriers from the analysis (r² = 0.4; r² = 0.58. Types of land use did not affect the biotic integrity (n = 26; df = 4; H = 4,860; p = 0.302, but natural and artificial barriers affected it (n = 26; df = 4; H = 11,027; p = 0.026. The IBI was not sensitive to variations in mesohabitat structure (F2,23 = 0.373; r² = 0.031; Axe 1 p = 0.620; Axe 2 p = 0.490. The IBI is certainly a reasonable instrument for evaluating changes in the environment, but we cannot ignore the fact that we were able to obtain the same result with any combinations of metrics. This makes its analysis and interpretation difficult. Full Text Available The serious overfishing of most Mediterranean stocks demands urgent reforms of the management measures aiming to guarantee the sustainability of resources, notably when compared with the improvement observed in other European areas. The new EU Common Fisheries Policy (CFP constitutes an excellent opportunity to introduce the changes needed for such a reform. According to this CFP, all European fish stocks should be brought to a state where they can produce at MSY by 2020 at the latest. The CFP also establishes that the objective of sustainable exploitation should be achieved through multiannual plans (MAPs adopted in consultation with relevant stakeholders having fisheries management interests such as fishermen, non-governmental organizations, and policy makers. Together with the MSY and MAP approaches, the new CFP contains several other measures, directed to guarantee the ecological and socio-economic sustainability of fisheries by means of the implementation of the ecosystem approach to fisheries management (EAFM. With this new perspective, the CFP wants to avoid past failures of fisheries management based on monospecific approaches. This study is a first step toward the application of the EAFM in the Balearic Islands by means of the development of a harvest strategy with defined objectives, targets, limits, and clear management control rules aimed at optimizing socioeconomic and ecological objectives in the framework of the new CFP. Different management scenarios designed to achieve that goal were modeled for the main demersal commercial fisheries from the study area, the bottom trawl, and small-scale fisheries. The work begins with a general description of those fisheries, their main fishing grounds, and assessments of the exploitation status of the main target stocks in order to establish the current situation. Secondly, alternative management scenarios to maximize catch and profits while considering societal objectives were evaluated by Variações espaciais na assembléia de peixes no Rio Paraíba do Sul (Barra Mansa, Barra do Piraí, Rio de Janeiro, Brasil Spatial variation in fish assemblage in the Paraíba do Sul River (Barra Mansa, Barra do Piraí, Rio de Janeiro, Brazil Francisco Gerson Araújo Full Text Available The Paraíba do Sul is a major running water system in southeastern Brazil (22º24' -22º26'S; 43º43' -44º16' W, draining one of the most important industrial regions in the country. Because of its location, it has suffered a large amount of alteration due to discharges of urban and industrial effluents with direct influence in the ichthyofauna. The aim of this study is to up-to-date information on fish assemblage structure and its variation in the vicinity of a major industrial effluent outfall at Volta Redonda industrial complex. A standardized fishing sampling program, using seines, casting nets, gill nets and net trays, was carried out from October 1997 to September 1999, at six sites in three zones of the river (upstream, nearby and downstream the industrial complex, aiming to compare variation in fish assemblage due to anthropogenic alteration. Fifty-two species in 13 families were identified in the total of 7286 fish specimens. Characidae was the most diverse family contributing with 28,85% to total number of species, followed by Cichlidae (17,31 %. Overall 15,38% of the species were introduced from other watershed systems, four exotic cichlids (genera Oreochromis Günther, 1862 and Tilapia A. Smith, 1840 and three aloctone (Cichla ocellaris Bloch & Schneider, 1801, Hyphessobricon callistus (Boulenger, 1900 e Metynnis maculatus (Kner, 1860. Lebistes reticulatus (Peters, 1859 was the most abundant fish species contributing to 39,7% of the total number of fish, followed by Geophagus brasiliensis (Quoy & Gaimard, 1824 amounting to 27,4%. Fish abundance was higher in the industrial zone, but only a few very dominant species were captured, while the upstream zone showed the most even community. Species replacement tolerance along the alterations gradient in the three zone seems to be a strategy to use the limited resources in the area. Martinez, I.; Ellis, J. R.; Scott, B.; Tidd, A. The Celtic Sea is a diverse fishing ground that supports important commercial fisheries for a range of demersal fish, large and small-bodied pelagic fish and a variety of cephalopods and other shellfish. A regional overview of the main commercial fish stocks of the Celtic Sea and of the fish that occur in the vicinity of Jones Bank are provided through analyses of landings data from English and Welsh vessels, and from scientific trawl surveys. Dedicated smaller scale sampling via trawl surveys combined with baited cameras on and around the Jones Bank were also analysed to investigate the importance of sandbank habitats with attention paid to the differences in the species occurring on the top of the bank in comparison to adjacent off-bank habitats. Official landing statistics for UK (English and Welsh) vessels indicated that the predominant commercial demersal species in ICES Divisions VIIg,h (in terms of quantities landed) were anglerfish, megrim, pollack and skates (Rajidae). There were, however, regional differences in the distribution of fish and fisheries, and the area surrounding Jones Bank (ICES Rectangles 28E1 and 28E2) supports fisheries for megrim, anglerfish, skates, hake, ling and turbot, with otter trawl, gillnet and beam trawl the main gears used. Recent survey data collected with GOV (Grande Ouverture Verticale) trawl from the Celtic Sea (ICES Divisions VIIe-h, 2007-2010) were used to highlight the broad scale distribution of the main fish assemblages in the Celtic Sea. Analyses of the fish and cephalopod catches from these surveys indicated that there were four broad assemblages in the area, including (i) a region around the Cornwall (which will also be partly influenced by the necessity to use rockhopper ground gear on these rough grounds), (ii) the shallower regions of the north-western Celtic Sea (including parts of the Bristol Channel), (iii) the deeper parts of the outer shelf and (iv) the central Celtic Sea. These data also provided van Denderen, Pieter Daniël; Lindegren, Martin; MacKenzie, Brian known. Here, we show how latitudinal differences in predatory fish can essentially be explained by the inflow of energy at the base of the pelagic and benthic food chain. A low productive benthic energy pathway favours large pelagic species, whereas equal productivities support large demersal......Large teleost (bony) fish are a dominant group of predators in the oceans and constitute a major source of food and livelihood for humans. These species differ markedly in morphology and feeding habits across oceanic regions; large pelagic species such as tunas and billfish typically occur...... in the tropics, whereas demersal species of gadoids and flatfish dominate boreal and temperate regions. Despite their importance for fisheries and the structuring of marine ecosystems, the underlying factors determining the global distribution and productivity of these two groups of teleost predators are poorly... ralis was initiated in 1878, initially using a steam tug ... species composition, catch seasonality, catch per unit effort (cpue) and size-at-recruitment over the time ... Changes in the Eastern Cape demersal inshore trawl fishery operating out of Port ... MATERIAL AND METHODS ... The model parameters were estimated by mini-. coast. An overall increase of double in exploitation of demersal fishery resources is envisaged compared to the present exploitation of 0.12 m.m.t.y. However, one should keep in mind the conservation strategies before exploiting these resources.... Feekings, Jordan P.; Bartolino, Valerio; Madsen, Niels the factors that influence discarding within the Danish Kattegat demersal fleet over the period 1997 to 2008. Generalised additive models were used to assess how discards of the 3 main target species, Norway lobster, cod and plaice, and their subcomponents (under and over minimum landings size) are influenced... Bower, L M; Piller, K R This study adopts an ecomorphological approach to test the utility of body shape as a predictor of niche relationships among a stream fish assemblage of the Tickfaw River (Lake Pontchartrain Basin) in southeastern Louisiana, U.S.A. To examine the potential influence of evolutionary constraints, analyses were performed with and without the influence of phylogeny. Fish assemblages were sampled throughout the year, and ecological data (habitat and tropic guild) and body shape (geometric morphometric) data were collected for each fish specimen. Multivariate analyses were performed to examine relationships and differences between body shape and ecological data. Results indicate that a relationship exists between body shape and trophic guild as well as flow regime, but no significant correlation between body shape and substratum was found. Body shape was a reliable indicator of position within assemblage niche space. © 2015 The Fisheries Society of the British Isles. Marchal, P.; Ulrich, Clara; Pastoors, M. The scope of this study is to investigate the extent to which area-based management may have influenced the fishing efficiency of the Danish and Dutch demersal fleets harvesting cod, plaice and sole in the North Sea. Special consideration is given to the 'plaice box', a restricted area where...... fishing is prohibited to towed-gear fleets of horsepower exceeding 300 hp. An index of fishing power is calculated as the log-ratio between the catch per unit effort (CPUE) of any vessel and some survey abundance index. Annual trends in fishing are calculated as the year-effect derived from a general...... linear model (GLM) analysis of the index of fishing power. The fishing efficiency of Danish gill-netters and, to some extent, Danish seiners, has overall increased inside the 'plaice box', whilst remaining relatively stable outside. However, the fishing efficiency of the other exemption fleets has... Distribuição, dominância e estrutura de tamanhos da assembleia de peixes da lagoa Mangueira, sul do Brasil Distribution, dominance and sizes structure of the fish assemblage in the Mangueira lake, southern Brazil Luiz G. S Artioli écies entre as porções norte e sul da lagoa. As 52 espécies registradas neste estudo representam uma alta riqueza de peixes na lagoa Mangueira, sobretudo quando comparada a outras lagoas costeiras do RS. Padrões diferenciados de composição e abundância de espécies parecem refletir características distintas dos habitats litorâneos amostrados.This study presents the composition of species, the distribution and dominance patterns, and the structure of sizes of the assemblage of fish in distinct habitats (littoral, deeper and near shore limnetic zone of the Mangueira lake, in the southern Brazil. Samples were taken in the north, south and central regions of the lake from 2001 to 2007 using a multi-gear approach (gillnet, cast net, beach seine, dip net and bottom trawling. A total of 52 species were identified, 46 in the littoral zone, 33 in the near shore limnetic zone and 26 in the deep zone, distributed in 17 families, of the which, Characidae, Cichlidae, Loricariidae, and Atherinopsidae were the most diverse. The dominant species summed up 91.1 %, 92.9 % and 82.7 % of the all individuals caught in the littoral, deeper and limnetic zone, respectively. The littoral zone was comprised of small fishes, nearly 70 % between 25 and 50 TL mm. The dominance patterns showed that, in this zone, 19,5 % of the species were dominant, although four of those also prevailed in the other zones. In the deep zone, 7,6% of the captured species were dominant, with similar sizes to the littoral zone. For the other species, the sizes resemble to the near shore limnetic zone. The near shore limnetic zone was comprised of larger fishes, the major part between 150 and 200 TL mm, such as the great characins, the toothless characin and the silverside fishes. A larger difference was observed in the composition of species between the littoral and limnetic zones, with the species Jenynsia multidentata, Bryconamericus iheringii, Hyphessobrycon luetkenii and Gymnogeophagus gymnogenys dominating the paper raises the questions where to locate aesthetics when planners and architects wishes to design for aesthetical experiences and sensations rather than formal objects. The paper will proceed through a brief outline of the recent notion of assemblage and affect in urban studies, planning theory...... happens to aesthetics and how does it change the existing social and geographical understanding of urban space? The paper sets out to reintroduce aesthetical aspects of affects and assemblages in relation to urban space and urban planning. It presupposes urban space as a continuous state of becoming where... Goudswaard, P.C.; Wanink, J.H.; Witte, F.; Katunzi, E.F.B.; Berger, M.R.; Postma, D.J. Understanding of migration patterns is essential in the interpretation of hydro-acoustic stock assessment data of partly demersal partly pelagic fish stocks. In this paper we provide this kind of information for some species that were common in the Mwanza Gulf of Lake Victoria in the 1980s, before Goudswaard, KPC; Wanink, JH; Witte, F; Katunzi, EFB; Berger, MR; Postma, DJ Understanding of migration patterns is essential in the interpretation of hydro-acoustic stock assessment data of partly demersal partly pelagic fish stocks. In this paper we provide this kind of information for some species that were common in the Mwanza Gulf of Lake Victoria in the 1980s, before Nielsen, J. Rasmus; Ulrich, Clara; Hegland, Troels J. the scientific advice, the development in recent years has been towards this gap being reduced. Management of the fisheries has undergone a number of structural and behavioral changes, and these have already yielded some positive results as the state of the demersal stocks in the North Sea have globally improved......, at least in the prosperous countries around the North Sea, provides only few jobs. Despite the above trends indicating positive effects of the most recent fisheries management of the North Sea mixed demersal fisheries there are a row of general problems in the present management. Population dynamics...... states’ ministers in the Council have exercised strong control over the fisheries management measures which have been developed and adopted on the background of proposals from the Commission and the Parliament, though since the ratification of the Lisbon Treaty the Parliament has assumed a role of co... composition and energy density of the prey and spatial distribution of the whiting, demonstrates the need for a sampling design that includes both pelagic and demersal layers when quantifying the food consumption of whiting.(C) 2000 The Fisheries Society of the British Isles.......Pelagic North Sea whiting Merlagius merlangus fed at night, while demersal whiting fed by day. The estimated specific daily ration ranged from 4.38 to 7.84% in 1992 and from 3.99 to 10.31% in 1993 using the in situ rate of gastric evacuation. Using Anderson's evacuation model the specific daily...... ration ranged from 0.41 to 1.66% in 1992 and from 0.78 to 1.75% in 1993. The specific daily rations were significantly different where energy density of stomach content by length class of whiting was significantly different between the two layers and years. The fact that daily ration was related to prey... Balatsas Lekkas, Angelos This thesis identifies how design processes emerge during the use of devices in healthcare, by attending to assemblages where contingencies of risk and harm co-exist with the contribution of healthcare professionals to the safe care of patients. With support from the field of Science and Technology...... practices of interdisciplinary care.... This paper asks what translanguaging could start to look like if it incorporated an expanded version of language and questioned not only to the borders between languages but also the borders between semiotic modes. Developing the idea of spatial repertoires and assemblages, and looking at data from a Bangladeshi-owned corner shop, this paper… Amores, A.; Rueda, L.; Monserrat, S.; Guijarro, B.; Pasqual, C.; Massutí, E. Ocean mean surface vorticity from gridded multi-mission satellite altimetry data was explored in the Western Mediterranean basin for the period 2000-2010, with the aim of comparing its variability with several species of the deep water fishery in the area. Monthly catches per unit of effort (CPUE) of adult red shrimp (Aristeus antennatus), reported in the deep water bottom trawl fishery developed off northern Mallorca Island displayed a good correlation with surface vorticity. This correlation could be explained by assuming that most of the surface vorticity episodes could reach the bottom, increasing the seabed velocities and producing sediment resuspensions, which could affect the near bottom water turbidity. A. antennatus would respond to this increased turbidity by moving downwards to the deeper waters. This massive displacement of red shrimp specimens away from the fishing grounds would consequently decrease their accesibility to fishing exploitation. This relationship between vorticity and catches also holds for other species , considered as by-catch of the deep water fishery in the area. Results appear to support the suggestion that the water turbidity generated by the vorticy episodes is significant enough to affect the dynamics of the demersal species. The way the surface vorticity observed can affect the bottom sediments is also investigated using a year-long moored near-bottom currentmeter and a sediment trap sited in the fishing grounds. Freshwater inflow has a strong impact on the biological, chemical and physical characteristics of estuaries, which in turn affect the distribution and abundance of estuarine organisms. Increased climatic variability associated with climate change is predicated to modify precipitation patterns, which will likely intensify floods in ... Gallo, N.; Navarro, E. C.; Yazzie, A. T.; Barry, J. P.; Levin, L. A. Predicting how demersal fish communities will respond as hypoxic areas expand with climate change requires an understanding of how existing oxygen gradients influence the abundance, diversity, and trophic ecology of demersal fish communities. A literature review of studies from continental margins with oxygen minimum zones in the Pacific, Atlantic, and Indian Ocean, is combined with new data from research cruises to the Gulf of California and the US West Coast, to examine how hypoxic areas influence the structure and function of demersal fish communities. Oxygen minimum zones (OMZs) are deep-sea environments where organisms experience chronic hypoxic and suboxic conditions and have persisted over much longer timescales than coastal eutrophication-induced hypoxic zones, allowing for the evolution of adaptations to low oxygen conditions. While coastal studies have found that fish are one of the most hypoxia-intolerant groups, representative demersal fish species in the orders Cottiformes, Scorpaeniformes, Pleuronectiformes, Gobiiformes, Perciformes, Lophiiformes, Carcharhiniformes, Ophidiiformes, Myxiniformes, and Gadiformes have evolved to exploit physiologically extreme OMZ environments and are important components of the benthic community. In OMZs, certain fish species are some of the most hypoxia-tolerant members of the megafauna community, present even under extremely low oxygen conditions (< 5 µmol/kg) where most invertebrates are absent, though these communities are typically characterized by single-species dominance. To explore differences in the trophic ecology of these "hypoxia-tolerant" fish communities, stable isotope and gut content analysis are used to compare the Southern California Bight OMZ core fish community to the hypoxia-intolerant upper slope fish community. Results show that fish living in the OMZ core have significantly enriched δ13C and δ15N signatures and feed on different prey items. Amores, Angel; Rueda, Lucía; Monserrat, Sebastià; Guijarro, Beatriz; Pasqual, Catalina; Massutí, Enric Monthly catches per unit of effort (CPUE) of adult red shrimp (Aristeus antennatus), reported in the deep water bottom trawl fishery developed on the Sóller fishing ground off northern Mallorca (Western Mediterranean), and the mean ocean surface vorticity in the surrounding areas are compared between 2000 and 2010. A good correlation is found between the rises in the surrounding surface vorticity and the drops in the CPUE of the adult red shrimp. This correlation could be explained by assuming that most of the surface vorticity episodes could reach the bottom, increasing the seabed velocities and producing sediment resuspension, which could affect the near bottom water turbidity. A. antennatus would respond to this increased turbidity disappearing from the fishing grounds, probably moving downwards to the deeper waters. This massive displacement of red shrimp specimens away from the fishing grounds would consequently decrease their accessibility to fishing exploitation. Similar although more intense responses have been observed during the downslope shelf dense water current episodes that occurred in a submarine canyon, northeast of the Iberian peninsula. The proposed mechanism suggesting how the surface vorticity observed can affect the bottom sediments is investigated using a year-long moored near-bottom current meter and a sediment trap moored near the fishing grounds. The relationship between vorticity and catches is also explored for fish species (Galeus melastomus, Micromesistius poutassou, Phycis blennoides) and other crustacean (Geryon longipes and Nephrops norvegicus), considered as by-catch of the deep water fishery in the area. Results appear to support the suggestion that the water turbidity generated by the vorticity episodes is significant enough to affect the dynamics of the demersal species. The ichthyoplankton assemblage of the Algoa Bay nearshore region in relation to coastal zone utilization by juvenile fish. ... The various taxa occurring in the ichthyoplankton are discussed in terms of distribution of adults and juveniles, breeding biology and available information on early life history. The paucity of larvae of ... Marcela C. Nascimento Full Text Available It is increasingly recognized that demersal communities are important for the functioning of continental shelf and slope ecosystems around the world, including tropical regions. Demersal communities are most prominent in areas of high detritus production and transport, and they link benthic and pelagic biological communities. To understand the structure and role of the demersal community on the southeastern Brazilian Bight, we constructed a trophodynamic model with 37 functional groups to represent the demersal community of the outer continental shelf and upper slope of this area, using the Ecopath with Ecosim 6 (EwE approach and software. The model indicates high production and biomass of detritus and benthic invertebrates, and strong linkages of these components to demersal and pelagic sub-webs. The level of omnivory indexes in this ecosystem was high, forming a highly connected trophic web reminiscent of tropical land areas. Although high levels of ascendency may indicate resistance and resilience to disturbance, recent and present fisheries trends are probably degrading the biological community and related ecosystem services. Ahmadia, Gabby N.; Tornabene, Luke; Smith, David J.; Pezold, Frank L. Factors shaping coral-reef fish species assemblages can operate over a wide range of spatial scales (local versus regional) and across both proximate and evolutionary time. Niche theory and neutral theory provide frameworks for testing assumptions and generating insights about the importance of local versus regional processes. Niche theory postulates that species assemblages are an outcome of evolutionary processes at regional scales followed by local-scale interactions, whereas neutral theory presumes that species assemblages are formed by largely random processes drawing from regional species pools. Indo-Pacific cryptobenthic coral-reef fishes are highly evolved, ecologically diverse, temporally responsive, and situated on a natural longitudinal diversity gradient, making them an ideal group for testing predictions from niche and neutral theories and effects of regional and local processes on species assemblages. Using a combination of ecological metrics (fish density, diversity, assemblage composition) and evolutionary analyses (testing for phylogenetic niche conservatism), we demonstrate that the structure of cryptobenthic fish assemblages can be explained by a mixture of regional factors, such as the size of regional species pools and broad-scale barriers to gene flow/drivers of speciation, coupled with local-scale factors, such as the relative abundance of specific microhabitat types. Furthermore, species of cryptobenthic fishes have distinct microhabitat associations that drive significant differences in assemblage community structure between microhabitat types, and these distinct microhabitat associations are phylogenetically conserved over evolutionary timescales. The implied differential fitness of cryptobenthic fishes across varied microhabitats and the conserved nature of their ecology are consistent with predictions from niche theory. Neutral theory predictions may still hold true for early life-history stages, where stochastic factors may be more Bergstr?m, Lena; Karlsson, Martin; Bergstr?m, Ulf; Pihl, Leif; Kraufvelin, Patrik Shallow nearshore habitats are highly valued for supporting marine ecosystems, but are subject to intense human-induced pressures. Mesopredatory fish are key components in coastal food webs, and alterations in their abundance may have evident effects also on other parts of the ecosystem. The aim of this study was to clarify the relationship between the abundance of coastal mesopredatory fish, defined as mid-trophic level demersal and benthic species with a diet consisting predominantly of inv... Li, Zengguang; Ye, Zhenjiang; Wan, Rong Surveys were conducted in five voyages in Haizhou Bay and its adjacent coastal area from March to December 2011 during full moon spring tides. The ichthyoplankton assemblages and the environmental factors that affect their spatial and seasonal patterns were determined. Totally 35 and 12 fish egg and larvae taxa were identified, respectively. Over the past several decades, the egg and larval species composition has significantly changed in Haizhou Bay and its adjacent waters, most likely corresponding with the alteration of fishery resources, which are strongly affected by anthropogenic activities and climate change. The Bray-Curtis dissimilarity index identified four assemblages: near-shore bay assemblage, middle bay assemblage and two closely related assemblages (near-shore/middle bay assemblage and middle/edge of bay assemblage). The primary species of each assemblage principally reflected the spawning strategies of adult fish. The near-shore bay assemblage generally occurred in near-shore bay, with depths measuring ichthyoplankton in each assemblage were determined by interactions between biological behavioral traits and oceanographic features, particularly the variation of local conditions within the constraint of a general reproductive strategy. The results of Spearman's rank correlation analysis indicated that both fish egg and larval abundance were positively correlated with depth, which is critical to the oceanographic features in Haizhou Bay. Vinther, Morten; Eero, Margit Evaluations of the effects of management measures on fish populations are usually based on the analyses of population dynamics and estimates of fishing mortality from stock assessments. However, this approach may not be applicable in all cases, in particular for data-limited stocks, which may...... GAM analyses to predict local cod densities and combine this with spatio-temporal data of fishing effort based on VMS (Vessel Monitoring System). To quantify local fishing impact on the stock, retention probability of the gears is taken into account. The results indicate a substantial decline...... in the impact of the Danish demersal trawl fleet on cod in the Kattegat in recent years, due to a combination of closed areas, introduction of selective gears and changes in overall effort.... Rita P Vasconcelos; Sébastien Villéger; François Guilhaumon Biodiversity is currently viewed as a framework encompassing multiple facets of the variety of life, including taxonomic and functional aspects. Species richness and composition of fish assemblages in estuaries is defined by global to local processes acting on community colonization. The present study further investigates how biodiversity of fish assemblages varies among estuaries globally, by simultaneously analysing taxonomic and functional richness and diversity of assemblages. A comprehen... Full Text Available Management of the Mediterranean demersal stocks has proven challenging mainly due to the multi-species character of the fisheries. In the present work, we focus on the multi-species demersal fisheries of the Aegean Sea (eastern Mediterranean aiming to study the effects of different management measures on the main commercial stocks, as well as to explore the economic viability of the fisheries depending upon these resources, by means of simulated projections. Utilizing the limited available data, our results demonstrated that, under the current exploitation pattern, the economic viability of the fleets is threatened, particularly if fuel prices increase. Additionally, the biological targets set for the most exploited species, such as hake, will not be met under the current management regime. The projections also showed that the only management scenario under which both resource sustainability and economic viability of the fisheries are ensured is the decrease of fleet capacity in terms of vessel numbers. In this case, however, measures to support the fisheries-dependent communities need to be implemented to prevent the collapse of local economies due to employment decrease. Scenarios assuming selectivity improvements would be also beneficial for the stocks but they showed low economic performance and their application would threaten the viability of the fleets, particularly that of the trawlers. McKenna, J.E.; Hunter, R. Douglas; Fabrizio, M.C.; Savino, J.F.; Todd, T.N.; Bur, M. Early life stage survival often determines fish cohort strength and that survival is affected by habitat conditions. The structure and dynamics of ichthyoplankton assemblages can tell us much about biodiversity and fish population dynamics, but are poorly understood in nearshore areas of the Great Lakes, where most spawning and nursery habitats exist. Ichthyoplankton samples were collected with a neuston net in waters 2-13 m deep weekly or biweekly from mid-April through August, during 3 years (2000-2002) as part of a study of fish assemblages in west-central Lake Erie. A suite of abiotic variables was simultaneously measured to characterize habitat. Cluster and ordination analyses revealed several distinct ichthyoplankton assemblages that changed seasonally. A lake whitefish (Coregonus clupeaformis) dominated assemblage appeared first in April. In May, assemblages were dominated by several percid species. Summer assemblages were overwhelmingly dominated by emerald shiner (Notropis atherinoides), with large gizzard shad (Dorosoma cepedianum) and alewife (Alosa pseudoharengus) components. This seasonal trend in species assemblages was also associated with increasing temperature and water clarity. Water depth and drift processes may also play a role in structuring these assemblages. The most common and widely distributed assemblages were not associated with substratum type, which we characterized as either hard or soft. The timing of hatch and larval growth separated the major groups in time and may have adaptive significance for the members of each major assemblage. The quality and locations (with reference to lake circulation) of spawning and nursery grounds may determine larval success and affect year class strength. Seasonal changes in a fish assemblage associated with mangroves in a coastal lagoon of Baja California Sur, Mexico Cambios estacionales de la comunidad de peces asociada a zonas de manglar en una laguna costera de Baja California Sur, México Full Text Available The fish assemblage in a coastal lagoon with mangroves known as "Rancho Bueno" was determined and associated with environmental parameters. We used an experimental otter trawl net to catch the fish, and 62 fish species were identified from 48 genera and 30 families. The most abundant species were: Etropus crossotus, Eucinostomus gracilis, Paralabrax maculatofasciatus, Sphoeroides annulatus, and Eucinostomus dowii. The water temperature changed seasonally, being warm from July through December and cold from January through June. We found more fish species during the warm season than during the cold season. The southern area of the coastal lagoon had the highest diversity and species richness. The small size of the fishes registered confirms the ecological role of coastal lagoons as nursery areas that offer protection and feeding to commercially important fish near Bahía Magdalena, Mexico.Se determinó la estructura de peces asociada a factores ambientales en una laguna costera con manglar denominada "Rancho Bueno". Se utilizó una red de arrastre experimental para la captura y se identificaron 62 especies de peces de 48 géneros y 30 familias. Las especies más importantes fueron Etropus crossotus, Eucinostomus gracilis, Paralabrax maculatofasciatus, Sphoeroides annulatus y Eucinostomus dowii. La temperatura del agua varió estacionalmente, siendo cálida de julio a diciembre y fría de enero a junio. Se registró un mayor número de especies de peces durante la época cálida comparada con la época fría. La zona sur de la laguna costera presentó una mayor diversidad y riqueza específica. El menor tamaño de los peces registrados, confirma el papel ecológico de las lagunas costeras, consideradas como áreas de crianza las cuales proporcionan protección y alimentación a los peces de importancia comercial cerca de Bahía Magdalena, México. Almir M. Cunico Full Text Available O objetivo do presente estudo foi avaliar padrões espaciais na composição, estrutura e distribuição das assembléias de peixes e suas relações com características abióticas em três córregos urbanos da cidade de Maringá, Paraná, Brasil. Peixes foram coletados ao longo de um gradiente longitudinal utilizando pesca elétrica nos meses de maio e novembro de 2004. Temperatura, nitrogênio, pH, oxigênio e fósforo foram as variáveis que mais influenciaram a análise de componentes principais (CPA. Riqueza, eqüitabilidade, índice de diversidade de Shannon-Wiener e o primeiro eixo da análise de correspondência com remoção do efeito do arco (DCA foram diretamente correlacionados com características ligadas ao impacto químico urbano. Adição de espécies prevaleceu nas estações de amostragem do córrego Miosótis e entre a cabeceira e porção intermediária nos córregos Nazaré e Mandacaru. Substituição ocorreu entre as porções intermediárias e foz desses córregos. A dominância da espécie tolerante Poecilia reticulata Peters, 1859 indicou a influência do impacto do meio urbano sobre as assembléias de peixes.The aim of the present study was to evaluate spatial patterns in composition, structure and distribution of fish assemblages and their relationships with abiotic characteristics in three urban streams of Maringá city, Paraná, Brazil. Fish were collected along the longitudinal gradient by electrofishing in May and November 2004. Temperature, nitrogen, pH, oxygen and phosphorous influenced at most the principal components analysis (PCA. Richness, evenness, Shannon-Wiener index and the first axis of detrended correspondence analysis (DCA were directly correlated with abiotic characteristics related to chemical urban impact. Species addition prevailed in Miosotis stream sampling stations, and between headwater and intermediary reaches in Nazaré and Mandacarú streams. Replacement occurred between intermediary and Estimates of fish-community size spectra are promising indicators of the impact of fishing on fish assemblages. Size spectra consist of logarithmic graphs of abundance plotted against fish body size. Size spectra may either be constructed from length frequency data or estimated from the mean sizes and abundances of the ... Rodriguez, J. M.; Gonzalez-Pola, C.; Lopez-Urrutia, A.; Nogueira, E. During summer, wind driven coastal upwelling dominates in the Central Cantabrian Sea (southern Bay of Biscay). Nevertheless, atmospheric forcing is highly variable and wind pulses may cause noticeable and fast hydrographic responses in the shelf region. In this paper, the composition and vertical distribution of the summer ichthyoplankton assemblage during the daytime at a fixed station, located on the Central Cantabrian Sea shelf, are documented. Also, the impact of a short-time scale hydrographic event on the abundance and structure of the larval fish assemblage is examined. Significant small-scale temporal hydrographic variability was observed. Currents showed changes in speed and direction and significant changes in thermocline depth were also observed. A total of 34 taxa of fish larvae were identified. Engraulis encrasicolus eggs and larvae of the shelf-dwelling species Trachurus trachurus, Capros aper and E. encrasicolus dominated the ichthyoplankton assemblage. The distribution of E. encrasicolus eggs and fish larvae was vertically structured. E. encrasicolus egg concentration increased exponentially towards the surface. Fish larvae showed a subsurface peak of concentration and their vertical distribution was not conditioned by thermocline depths. The short term hydrographic event did not affect the vertical distribution of fish larvae but it accounted for significant temporal changes in larval fish assemblage structure and abundance. Results suggest that temperature and light intensity are important factors in the vertical distribution of fish larvae. They also indicate that the temporal monitoring of the larval fish assemblage in this region requires multiple sampling sites. Lin, Han-Yang; Chiu, Mei-Yun; Shih, Yu-Ming; Chen, I.-Shiung; Lee, Ming-An; Shao, Kwang-Tsao The East China Sea (ECS) is one of the most important fish spawning and nursery grounds in the north Pacific. Even though summer is an important spawning season for many fishes in the region, large-scale molecular identification studies on ichthyoplankton during this season are few. In this study, we sampled 8,933 fish eggs and 12,161 fish larvae from 25 stations during the summer of 2009. Using DNA barcoding, a number of the fish eggs and larvae were identified and classified into 45 and 124 taxa, respectively. Principal component analysis (PCA) categorized the inshore stations of the Changjiang Diluted Water area as having the hydrographic features of low sea surface temperature (SST), salinity (SSS) and high chlorophyll a (SSC) contents, whereas the continental shelf and offshore stations under the influence of the Kuroshio Current displayed the opposite results. Ichthyoplankton was more abundant at the inshore stations than the offshore stations, but species diversity was lower at the former locations. Species compositions of both fish eggs and fish larvae at the 25 stations were categorized into three different assemblages based on a non-metric multidimensional scaling analysis. Combining the assemblage patterns of ichthyoplankton with the results of the PCA and satellite images of SST and SSC showed that the assemblage patterns of fish eggs were correlated with water mass, while those of the fish larvae were not. Miranda, Leandro E.; Keretz, Kevin R.; Gilliland, Chelsea R. Serial impoundment of major rivers leads to alterations of natural flow dynamics and disrupts longitudinal connectivity. Catostomid fishes (suckers, family Catostomidae) are typically found in riverine or backwater habitats yet are able to persist in impounded river systems. To the detriment of conservation, there is limited information about distribution of catostomid fishes in impounded rivers. We examined the longitudinal distribution of catostomid fishes over 23 reservoirs of the Tennessee River reservoir cascade, encompassing approximately 1600 km. Our goal was to develop a basin-scale perspective to guide conservation efforts. Catostomid species composition and assemblage structure changed longitudinally along the reservoir cascade. Catostomid species biodiversity was greatest in reservoirs lower in the cascade. Assemblage composition shifted from dominance by spotted sucker Minytrema melanops and buffalos Ictiobus spp. in the lower reservoirs to carpsuckers Carpiodes spp. midway through the cascade and redhorses Moxostoma spp. in the upper reservoirs. Most species did not extend the length of the cascade, and some species were rare, found in low numbers and in few reservoirs. The observed gradients in catostomid assemblages suggest the need for basin-scale conservation measures focusing on three broad areas: (1) conservation and management of the up-lake riverine reaches of the lower reservoirs, (2) maintenance of the access to quality habitat in tributaries to the upper reservoirs and (3) reintroductions into currently unoccupied habitat within species' historic distributions shallow borehole drilled in the southern coastal basin of Tanzania with the aim of characterizing foraminifera and palynomorphs assemblage changes aiming at reconstructing ..... decline in temperature at EOT which caused the extinction of ... Feekings, Jordan P. Discarding of aquatic organisms is a global problem in the world’s fisheries, where more than 7 million tonnes are caught and subsequently discarded each year. The understanding of what drives discarding can help provide mitigation measures in the future. Altering management measures which result...... in high discard rates/ratios may prove beneficial not only to the economic viability of the fishery but also to the biological functioning of the ecosystem. The present Ph.D. thesis, titled “Discarding Discards: Identification of influential factors and possible mitigation tools in demersal trawl...... an examination of the efficiency of technical regulations currently in force and retrospective analyses of the efficiency of such measures in the past. The thesis consists of a review and 4 papers. Paper I is an investigation of the factors that can potentially influence the discarding of commercial species... Feyrer, Frederick; Cloern, James E; Brown, Larry R; Fish, Maxfield A; Hieb, Kathryn A; Baxter, Randall D Estuaries are dynamic environments at the land-sea interface that are strongly affected by interannual climate variability. Ocean-atmosphere processes propagate into estuaries from the sea, and atmospheric processes over land propagate into estuaries from watersheds. We examined the effects of these two separate climate-driven processes on pelagic and demersal fish community structure along the salinity gradient in the San Francisco Estuary, California, USA. A 33-year data set (1980-2012) on pelagic and demersal fishes spanning the freshwater to marine regions of the estuary suggested the existence of five estuarine salinity fish guilds: limnetic (salinity = 0-1), oligohaline (salinity = 1-12), mesohaline (salinity = 6-19), polyhaline (salinity = 19-28), and euhaline (salinity = 29-32). Climatic effects propagating from the adjacent Pacific Ocean, indexed by the North Pacific Gyre Oscillation (NPGO), affected demersal and pelagic fish community structure in the euhaline and polyhaline guilds. Climatic effects propagating over land, indexed as freshwater outflow from the watershed (OUT), affected demersal and pelagic fish community structure in the oligohaline, mesohaline, polyhaline, and euhaline guilds. The effects of OUT propagated further down the estuary salinity gradient than the effects of NPGO that propagated up the estuary salinity gradient, exemplifying the role of variable freshwater outflow as an important driver of biotic communities in river-dominated estuaries. These results illustrate how unique sources of climate variability interact to drive biotic communities and, therefore, that climate change is likely to be an important driver in shaping the future trajectory of biotic communities in estuaries and other transitional habitats. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Lee, C.-C.; Wang, T.; Hsieh, C.-Y.; Tien, C.-J. Contaminated levels of butyl- and phenyltin compounds, tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenlytin (DPT), and monophenyltin (MPT), were investigated in pelagic, demersal and cultured fish species from different seasons and locations in Taiwan. Seasonal variations were found in fishes from Wuchi and Hsingta fishing harbors for their butyltin levels (winter > summer) with the opposite trend for phenyltins in fishes from Patoutzu fishing harbor and demersal fishes from four fishing harbors (summer > winter). Fish liver contained the lowest percentage of TBT and the highest percentage of TPT among six organotin compounds. Consumption of contaminated pelagic species and fishes from Hsingta fishing harbor had the highest hazard index. However, the hazard quotients and hazard indices were all less than 1, suggesting a daily exposure at these levels of TBT, DBT and TPT may not be likely to cause any deleterious effects during lifetime in human population. - Spatial and seasonal variations in accumulation of organotins were showed by fishes with different living patterns and the potential health risk to ingest such fishes Lee, C.-C. [Department of Environmental and Occupational Health, Medical College, National Cheng Kung University, 138 Sheng Li Road, Tainan 704, Taiwan (China); Research Center of Environmental Trace Toxic Substances, National Cheng Kung University, 138 Sheng Li Road, Tainan 704, Taiwan (China); Wang, T. [Department of Environmental and Occupational Health, Medical College, National Cheng Kung University, 138 Sheng Li Road, Tainan 704, Taiwan (China); Hsieh, C.-Y. [Research Center of Environmental Trace Toxic Substances, National Cheng Kung University, 138 Sheng Li Road, Tainan 704, Taiwan (China); Tien, C.-J. [Department of Industrial Safety and Hygiene, Chung Hwa College of Medical Technology, 89 Wen-Hwa 1st Street, Jen-Te 717, Tainan, Taiwan (China)]. E-mail: email@example.com Contaminated levels of butyl- and phenyltin compounds, tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenlytin (DPT), and monophenyltin (MPT), were investigated in pelagic, demersal and cultured fish species from different seasons and locations in Taiwan. Seasonal variations were found in fishes from Wuchi and Hsingta fishing harbors for their butyltin levels (winter > summer) with the opposite trend for phenyltins in fishes from Patoutzu fishing harbor and demersal fishes from four fishing harbors (summer > winter). Fish liver contained the lowest percentage of TBT and the highest percentage of TPT among six organotin compounds. Consumption of contaminated pelagic species and fishes from Hsingta fishing harbor had the highest hazard index. However, the hazard quotients and hazard indices were all less than 1, suggesting a daily exposure at these levels of TBT, DBT and TPT may not be likely to cause any deleterious effects during lifetime in human population. - Spatial and seasonal variations in accumulation of organotins were showed by fishes with different living patterns and the potential health risk to ingest such fishes. Hoffmann, Erik; Dolmer, Per The high blue mussel catches in a fjord system in Denmark, the visible effects of dredging by resuspension of bottom sediment and the possible destruction of benthic flora and fauna have all raised concerns about the impact on the ecosystem. As a consequence, a formerly lucrative blue mussel...... fishing area in the fjord was closed on dredging in 1988. This made it possible to investigate changes in the distribution of fish and benthos based on experimental fishing with trawl, set net and traps, and scuba diving during 1981-1998. The investigations showed no long-term effects of mussel dredging...... on the distribution of fish and epibenthic invertebrates, and the closed area appeared to have had no influence on the demersal fish and epibenthic fauna. Factors other than mussel dredging appear to determine the observed spatial and temporal variability in the ecosystem. (C) 2000 International Council... Full Text Available This study aimed to determine the distribution and relative abundance of freshwater fishes in the Tsitsikamma National Park. Fish assemblages in six river systems were sampled in 2001, with a total of 323 fish from eight species recorded. Indigenous fish collected included four freshwater species (Pseudobarbus afer, Pseudobarbus tenuis, Sandelia capensis, Anguilla mossambica, three estuarine species (Monodactylus falciformis, Caffrogobius gilchristi, Myxus capensis, and one alien (Micropterus salmoides. One additional indigenous species (Galaxias zebratus and two aliens (Salmo trutta, Oncorhynchus mykiss could potentially occur within the park. The topography and locality of the park presents a unique opportunity to meaningfully conserve the endangered P. tenuis as well as other fish characteristic of the eastern reaches of the Cape Floristic Region. Management action is required to minimise opportunities for further establishment and spread of alien fish species and to conserve indigenous fish assemblages within the park. Di Lena, Gabriella; Casini, Irene; Caproni, Roberto; Fusari, Andrea; Orban, Elena Total mercury levels were meas	<urn:uuid:dcf5f90b-4252-4f92-8a21-8d84d77a4377>	2.796875	132,546	Content Listing	Science & Tech.	23.129618	95,577,786
This soot-laden Brown Cloud is affecting South Asian climate as much or more than carbon dioxide and cause premature deaths of 100 000s annually, yet its sources have been poorly understood. In this week's issue of Science Örjan Gustafsson and colleagues at Stockholm University and in India use a novel carbon-14 method to constrain that two-thirds of the soot particles are from biomass combustion such as in household cooking and in slash-and-burn agriculture. Brown Clouds, covering large parts of South and East Asia, originate from burning of wood, dung and crop residue as well as from industrial processes and traffic. Previous studies had left it unclear as to the relative source contributions of biomass versus fossil fuel combustion. Combustion-derived soot particles are key components of the Brown Cloud in Asia. The soot absorbs sunlight and thereby heats the atmosphere while cooling Earth's surface by shading. The net effect of soot on climate warming in South Asia is rivaling that of carbon dioxide. The Swedish-Indian team managed to address the uncertainty of the soot sources by the first-ever microscale measurements of natural C-14 (half-life of 5700 years) of atmospheric soot particles intercepted on a mountain top in western India and outside SW India on the Hanimaadhoo island of the Maldives. Their results, presented in the Science article, demonstrated that the brown cloud soot was persistently about two-thirds from burning of contemporary biomass (C-14 "alive") and one-third from fossil fuel combustion (C-14 "dead"). These findings provide a direction for actions to curb emissions of Brown Clouds. Örjan Gustafsson, a professor of biogeochemistry at Stockholm University and leader of the study, says that the clear message is that efforts should not be limited to car traffic and coal-fired power plants but calls on fighting poverty and spreading India-appropriate green technology to limit emissions from small-scale biomass burning. "More households in South Asia need to be given the possibility to cook food and get heating without using open fires of wood and dung" says Gustafsson. The rewards of decreasing soot emissions from biomass combustion may be rapid and sizeable. Globally, soot accounts for roughly half the warming potential of carbon dioxide. While carbon dioxide levels in the atmosphere respond on a sluggish 100 yr timescale to reductions in emissions, Brown Cloud soot particles only reside in the atmosphere for days-weeks raising the hope for a rapid response of the climate system. Several additional positive effects would result from a reduction on Brown Cloud soot particle emissions. A recent report by the United Nations Environment Program, Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia (http://www.rrcap.unep.org/abc/impact/) outlines severe effects including melting of the Himalayan glaciers and weather systems becoming more extreme. The Brown Cloud is also having impact on agriculture and air quality in Asia. Henning Rodhe, a professor of chemical meteorology at Stockholm University, vice-chair of the UNEP Atmospheric Brown Cloud Program and also co-author of the Science article, states that the report finds that 340 000 people in China and India die each year from cardiovascular and respiratory diseases that can be traced to human-induced emissions of combustion particles. "The impact on health alone is a strong reason to reduce these Brown Clouds" says Rodhe.Further information Reporters may contact the AAAS-Science SciPak team at +1-202-326-6440 or email@example.com to receive an official version of the Science paper during the embargo.Pressofficer: Maria Erlandsson; firstname.lastname@example.org; Further reports about: > Atmospheric > C-14 > Cloud Computing > Traffic > biomass combustion > carbon dioxide > climate system > climate- and health-afflicting soot pollution > combustion processes > contemporary biomass > household cooking > industrial processes > slash-and-burn agriculture > soot-laden Brown Cloud > various burning Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany 25.06.2018 \| Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF Dry landscapes can increase disease transmission 20.06.2018 \| Forschungsverbund Berlin e.V. A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Power and Electrical Engineering 20.07.2018 \| Information Technology 20.07.2018 \| Materials Sciences	<urn:uuid:140df7be-9c6f-4464-8921-63b53e3cb9b3>	3.78125	1,432	Content Listing	Science & Tech.	39.102224	95,577,797
What is low-code? Low-Code is a visual development approach to application development enabling a spectrum of developers of varied experience to create applications for web and mobile using drag-and-drop components and model driven logic through a graphic user interface. Low-Code platforms relieve non-technical developers from having to know traditional programming languages and support professional developers by abstracting tedious plumbing and infrastructure tasks required to stand up and maintain applications. Working together, developers in the business and IT create, iterate, and release applications in a fraction of the time it takes through traditional development methods. Components of a low-code platform Continuous integration capabilities merge model changes into a version control repository upon completing a task. Committing code triggers the automated build system to grab the latest code from the shared repository, builds, tests, and validates the master branch before deploying to production. Rome wasn’t built in a day, but your app could be Don’t Repeat Yourself (DRY) states, “Every piece of knowledge must have a single, unambiguous, authoritative representation within a system”. Reusability helps developers deliver applications faster and promotes consistency across application structure from project to project. This makes it easy for developers to ramp from one project to another with ease, isolate problems and resolve them quickly for all apps using a component and increase application portfolio quality. Omni-channel App Development Build one code base for all devices Rather than support independent code and tooling for each incompatible target, developers are looking for ways to unify development activities and serve many targets from a single, modular code base. Openness and Extensibility Fast integrations, complete control Responsive development environments support building for any form factor without having to maintain dedicated code or logic. Package and deploy applications in as few as one-click using cloud native architectures and integrated tools for app store publication. Go fast without worrying about risk Built-in automated testing, proactive quality monitoring, and real-time performance management. Smart and Connected Access next generation technologies Connect to IoT, AI, machine learning, blockchain, and cognitive services without needing to be a domain expert. Deploy to the cloud of your choice with just one click Take advantage of a public cloud that automatically manages application reliability and scalability with simple configuration, reducing cost and effort to maintain infrastructure. Or deploy to a private cloud or on premises for total control. What can you create with a low-code platform? Unlock the value from emerging technologies like IoT, AI, machine learning, and blockchain following a test and learn approach. Low-Code makes exploring and integrating next generation technologies accessible for business users and developers with drag and drop ease, enabling them to create functional prototypes and iterate toward their next great application at scale. Improve satisfaction, retention and revenue with user experiences that delight customers and partners. Low-Code platforms include UI frameworks with patterns, building blocks, and widgets developers leverage to build engaging applications without needing a UX background. In addition, these assets are customizable to match the design language of your organization. Automate manual and paper-based processes to increase accuracy and quality while reducing costs. Low-Code platforms make it easy to create applications for capturing information and include connectors out of the box for integrating your applications to core systems. Enhance and modernize your existing applications with the latest advancements in user experience, application architectures like microservices, and continuous deployment. Integrate quality and performance management tools to improve reliability and maintainability throughout the application lifecycle. Businesses are using low-code platforms to turn their app strategy into a reality Build apps that keep up with customer needs. Streamline processes to innovate faster. Create apps without breaking budget. Mendix’s low-code platform brings app development into the future Empower a continuum of developers Introduce citizen developers to application development with WYSIWYG tools for creating functional prototypes and productivity applications rapidly. Provide professional developers with an IDE that enhances their productivity and enables them to communicate in an easy to understand visual way. Promote iterative development Integrated project management, collaboration, and feedback tools share the domain specific knowledge of the business and professional developers to communicate requirements, iterate on applications as a team, and respond to customers with agility. Create smart experiences Incorporate next generation technologies like IoT, blockchain, and artificial intelligence into applications without needing specialized skills. Deploy web-scale applications Release applications to the environment you choose with flexible deployment capabilities to the cloud or on premises using Cloud Foundry, or Docker with Kubernetes. Frequently Asked Questions - Low-Code and Agile Development? - Mendix Low-Code development adapts well to the Agile methodology with a suite of tools to foster collaboration and transparency throughout the application development lifecycle. The Mendix Platform Portal is the central hub for project and story management, communication, and feedback. These elements flow directly into the development environment and the application itself for users to navigate and address items directly and easily. - Best Low-Code Tools? - The best Low-Code tools are inclusive of the business and provide them tools to actively contribute and collaborate throughout the application development lifecycle. Mendix integrates collaboration into every facet of the platform, uses intuitive drag-and-drop development environments for creating engaging user interfaces and visual logic, and allows you to implement your own design language for applications to represent your brand. - Low-Code vs No Code? - Low-Code platforms allow developers to extend applications with their own coded enhancements. No-Code platforms apply constraints to the development environment limiting the user’s ability to extend their application beyond the vendor’s supplied solution. The Mendix platform is a governed platform supporting a spectrum of developers. Citizen developers use Mendix Low-Code tools to build productivity applications or start UI development on enterprise apps through a governed experience. Business and professional developers use Mendix Low-Code tools to create enterprise applications, REST APIs, microservices and more. When custom code is necessary, professional developers encapsulate custom code they write into shareable modules for the whole development team to drag-and-drop into their applications. - What is the Low-Code Application Development Process? - Low-Code lends itself well to the agile methodology of application development. Mendix supports agile development with an integrated project management application in the Platform Portal. Team members add stories to an application which flow into the development environment. While agile sprints result in a culmination of work and feedback over a period of time, Mendix feedback mechanisms promote iterations during sprints increasing development speed and accuracy, and reducing time to value. - Best Low-Code Platform? - Mendix formed in 2005 to transform the way lines of business collaborate with IT development teams to deliver applications while making it easier and faster for developers to create applications using a model driven approach. Both Forrester and Gartner have validated our vision with Gartner moving our high productivity application platform as a service (hpaPaas) from a niche player in 2014 to the leaders quadrant for the second consecutive year in 2018. As the only application development platform to support the spectrum of developers within the enterprise with purpose built tools, integrated collaboration and cloud native architecture, Mendix leads the way for the rest of the category. - Low-Code and Digital Transformation? - Low-Code is a catalyst for digital transformation in organizations because visual, model driven development presents logic in a language anyone in the application lifecycle can understand. Mendix uses this common language with integrated collaboration tools to help the development team (which includes the business) to reach alignment early and often in the application lifecycle. Developers are more efficient because the tools Mendix provides increase quality and consistency across the development team. The result is application throughput increases, delivered applications accurately drive positive business outcomes and the business is more likely to adopt the solutions because they have a greater investment and understanding of the process. - What is visual development/how does it work? - Visual development is a more intuitive way to build applications. Using model-driven development concepts to visually define the user interface, logic, and data model, Mendix empowers a spectrum of developers from citizen developers to professional developers to develop native mobile applications, web applications, APIs, microservices, and more. Because the development environment is visual and model driven, users gain proficiency in a fraction of the time it takes to master a traditional language. And if hand coding is required, professional developers can encapsulate logic and functionality into modules for the rest of the development team to reuse in their projects. On average, customers realize six to ten times productivity improvement using Mendix over traditional hand coding approaches to application development. - How does low-code development compare to terms like high-productivity aPaaS and RAD? - High productivity application platform as a service (hpaPaaS) is a term popularized by Gartner to categorize platforms that support declarative, model driven design and one-click deployment. hpaPaaS solutions include rapid application development (RAD) capabilities along with application deployment and execution services in the cloud. Both hpaPaaS and Low-Code provide levels of abstraction with an integrated set of tools to accelerate application delivery. Rapid application development (RAD) is a concept that products can be developed faster and of higher quality through: Gathering requirements using workshops or focus groups; prototyping and early, reiterative user testing of designs; the re-use of software components and more. Mendix is a Low-Code development platform facilitating the practical implementation of RAD with visual development capabilities to enable rapid, iterative and collaborative application design and development. With Mendix business and IT align on requirements through integrated project management tools modeled after agile, they share prototypes to gather feedback and refine requirements, and reuse models and components to speed development and enable more developers. - How to build an app without code? - Low-Code platforms abstract away application development decisions like what database to use, the language to write the back end, and the front-end framework to create the user interface and experience. Mendix enables anyone – from your most senior developers to business analysts with no programming experience – to build enterprise grade applications at speed, collaborating across the organization with greater transparency, and with control using a governed platform promoting quality and consistency every step of the way.	<urn:uuid:12c24d3b-85f7-4fdf-b156-6cd563c12075>	2.53125	2,138	About (Org.)	Software Dev.	5.987168	95,577,807
A group of German scientists has now come up with an environmentally friendly method that they say could do just that. The technique, dubbed carbon farming, consists in planting trees in arid regions on a large scale to capture CO2. They publish their study today in Earth System Dynamics, a journal of the European Geosciences Union (EGU). Processes involved in carbon farming. Technological and economic issues include the set up and operation of desalination plants and large-scale irrigation and their power supply, such as the production of bioenergy from the plantation. Land-surface-atmosphere processes, including heat release and CO2 absorption, also play a role in carbon farming. These modify the atmospheric boundary layer (ABL, the lowest part of the atmosphere) in such a way that may lead to the formation of clouds and precipitation. Becker et al. 2013 “Carbon farming addresses the root source of climate change: the emission of carbon dioxide by human activities,” says first-author Klaus Becker of the University of Hohenheim in Stuttgart. “Nature does it better,” adds Becker’s colleague Volker Wulfmeyer, “if we understand and can make use of it in a sustainable manner.” When it comes to sequestering carbon from the atmosphere, the team shows that _Jatropha curcas_ does it better. This small tree is very resistant to aridity so it can be planted in hot and dry land in soil unsuitable for food production. The plant does need water to grow though, so coastal areas where desalinated seawater can be made available are ideal. “To our knowledge, this is the first time experts in irrigation, desalination, carbon sequestration, economics and atmospheric sciences have come together to analyse the feasibility of a large-scale plantation to capture carbon dioxide in a comprehensive manner. We did this by applying a series of computer models and using data from _Jatropha curcas_ plantations in Egypt, India and Madagascar,” says Wulfmeyer. The new Earth System Dynamics study shows that one hectare of _Jatropha curcas_ could capture up to 25 tonnes of atmospheric carbon dioxide per year, over a 20 year period. A plantation taking up only about 3% of the Arabian Desert, for example, could absorb in a couple of decades all the CO2 produced by motor vehicles in Germany over the same period. With about one billion hectares suitable for carbon farming, the method could sequester a significant portion of the CO2 added to the atmosphere since the industrial revolution. But there are more advantages. Carbon farming’s price tag ranges from 42 to 63 euros per tonne of CO2, making it competitive with other CO2-reduction techniques such as carbon capture and storage. Further, after a few years, the plants would produce bioenergy (in the form of tree trimmings) to support the power production required for the desalination and irrigation systems. “From our point of view, afforestation as a geoengineering option for carbon sequestration is the most efficient and environmentally safe approach for climate change mitigation. Vegetation has played a key role in the global carbon cycle for millions of years, in contrast to many technical and very expensive geoengineering techniques,” explains Becker. The main limitations to implementing this method are lack of funding and little knowledge of the benefits large-scale plantations could have in the regional climate, which can include increase of cloud coverage and rainfall. The new Earth System Dynamics paper presents results of simulations looking into these aspects, but there is still a lack of experimental data on the effects of greening arid regions. Also, potential detrimental effects such as the accumulation of salt in desert soils need to be evaluated carefully. The team hopes the new research will get enough people informed about carbon farming to establish a pilot project. “We strongly recommend more emphasis is put on this technology – at both small and large scales – and that more research is done to investigate its benefits in comparison to other geoengineering approaches,” concludes Wulfmeyer.More information The peer-reviewed scientific article is available online, from the publication date onwards, at http://www.earth-syst-dynam.net/recent_papers.html. To obtain a copy of the paper before the publication date, please email Bárbara Ferreira at firstname.lastname@example.org. The discussion paper (not peer-reviewed) and reviewers’ comments are available at http://www.earth-syst-dynam-discuss.net/3/1221/2012/esdd-3-1221-2012.html The team is composed of K. Becker (Institute for Animal Production in the Tropics and Subtropics, University of Hohenheim, Stuttgart, Germany), V. Wulfmeyer (Institute of Physics and Meteorology, University of Hohenheim), T. Berger (Institute for Agricultural Economics and Social Sciences in the Tropics and Subtropics, University of Hohenheim), J. Gebel (S.T.E.P. Consulting GmbH, Aachen, Germany) and W. Münch (EnBW Energie Baden-Württemberg A.G., Karlsruhe, Germany). The European Geosciences Union (EGU) is Europe’s premier geosciences union, dedicated to the pursuit of excellence in the Earth, planetary, and space sciences for the benefit of humanity, worldwide. It is a non-profit interdisciplinary learned association of scientists founded in 2002. The EGU has a current portfolio of 15 diverse scientific journals, which use an innovative open access format, and organises a number of topical meetings, and education and outreach activities. Its annual General Assembly is the largest and most prominent European geosciences event, attracting over 10,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, energy, and resources. The 2014 EGU General Assembly is taking place is Vienna, Austria from 27 April to 2 May 2014. For information regarding the press centre at the meeting and media registration, please check http://media.egu.eu closer to the time of the conference. If you wish to receive our press releases via email, please use the Press Release Subscription Form at http://www.egu.eu/news/subscribe/. Subscribed journalists and other members of the media receive EGU press releases under embargo (if applicable) 24 hours in advance of public dissemination.Contact (Press release on the EGU website) Dr. Bárbara Ferreira \| idw New research calculates capacity of North American forests to sequester carbon 16.07.2018 \| University of California - Santa Cruz Scientists discover Earth's youngest banded iron formation in western China 12.07.2018 \| University of Alberta For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 17.07.2018 \| Information Technology 17.07.2018 \| Materials Sciences 17.07.2018 \| Power and Electrical Engineering	<urn:uuid:3d10ecdd-f932-4f05-afa0-72e00fe33671>	3.9375	2,035	Content Listing	Science & Tech.	38.268545	95,577,837
The transportation of certain molecules into and out of the cell nucleus takes place via nuclear pores. For some time, detailed research has been conducted into how these pores embedded in the nuclear envelope are structured. Now, for the first time, biochemists from the University of Zurich have succeeded in elucidating the structure of the transportation channel inside the nuclear pores in high resolution using high-performance electron microscopes. An active exchange takes place between the cell nucleus and the cytoplasm: Molecules are transported into the nucleus or from the nucleus into the cytoplasm. In a human cell, more than a million molecules are transported into the cell nucleus every minute. In the process, special pores embedded in the nucleus membrane act as transport gates. These nuclear pores are among the largest and most complex structures in the cell and comprise more than 200 individual proteins, which are arranged in a ring-like architecture. They contain a transportation channel, through which small molecules can pass unobstructed, while large molecules have to meet certain criteria to be transported. Now, for the first time, an UZH research team headed by Professor Ohad Medalia has succeeded in displaying the spatial structure of the transport channel in the nuclear pores in high resolution. “Molecular gate” discovered in the pore channel For their study, the scientists used shock-frozen specimens of clawed frog oocytes. With the aid of cryo-electron microscopes, Medalia’s team was able to display the miniscule nuclear pores, which were merely a ten thousandth of a millimeter in diameter, at a considerably higher resolution than ever before. As a result, they uncovered new details: “We discovered a previously unobserved structure inside the nuclear pore that forms a kind of molecular gate, which can only be opened by molecules that hold the right key,” explains Medalia. This “molecular gate” is the so-called spoke ring, which is sandwiched between two other rings and extends inside the nuclear pores. The gate itself consists of a fine lattice, which enables small molecules to slip through unobstructed. The new, high-resolution presentation of the nuclear pore structure leads to a better understanding of why certain molecules are allowed to pass through the nuclear pores while others are turned away. It also helps improve our understanding of the development of some diseases that involve a defective transportation to the nuclear pores – such as intestinal, ovarian and thyroid cancer. M. Eibauer, M. Pellanda, Y. Turgay, A. Dubrovsky, A. Wild, and O. Medalia: Structure and Gating of the Nuclear Pore Complex. Nature Communications. June xx, 2015. doi: 10.1038/ncomms8532 Cryo-electron microscopy at the University of Zurich Cryo-electron tomography is a method to render cell structures three-dimensionally visible in their natural environment in high resolution using both electron microscopy and computer imaging. The cells are shock-frozen in liquid nitrogen at minus 190 degrees. The cell structures remain intact in a quasi-living state, which means that they no longer need to be pre-treated with harmful chemicals. Extremely powerful electron beams also enable scientists to study thick sections or entire flat specimens (up to approximately 500 nm). Ohad Medalia, a pioneer in the field of cryo-electron microscopy, was appointed as a Professor of Biochemistry at the University of Zurich in 2010. Thanks to the generous support from the Mäxi Foundation, two high-performance electron microscopes of the type “Polara” and “Titan Krios” could be purchased. Today, they are operated together with UZH’s Center for Microscopy and Image Analysis and have expanded UZH’s range of technology considerably. Prof. Ohad Medalia Department of Biochemistry University of Zurich Tel.: +41 44 635 55 22 University of Zurich Tel.: +41 44 634 44 64 Nathalie Huber \| Universität Zürich Further reports about: > Biochemistry > Cryo-electron tomography > Microscopy > Molecules > Nature Communications > cell nucleus > cell structures > complex structures > cryo-electron microscopy > cytoplasm > electron beams > electron microscopes > electron microscopy > harmful chemicals > human cell > individual proteins > large molecules > natural environment > oocytes > pores > proteins > small > small molecules > spatial structure > structure > structures > thyroid cancer World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes 17.07.2018 \| Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt Plant mothers talk to their embryos via the hormone auxin 17.07.2018 \| Institute of Science and Technology Austria For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 17.07.2018 \| Information Technology 17.07.2018 \| Materials Sciences 17.07.2018 \| Power and Electrical Engineering	<urn:uuid:dd0f554b-84b5-48c8-b0e6-6ca088f5cee2>	3.25	1,616	Content Listing	Science & Tech.	33.880212	95,577,838
Scientists from Zoological Survey of India (ZSI) have discovered new species of water strider named Ptilomera nagalanda Jehamalar and Chandra in Nagaland. It was found in river Intanki in Peren district of Nagaland. This newly discovered species belongs to Ptilomera agriodes genus. It measures about 11.79 mm and has long slender legs. It has orange with black stripes on dorsal side and pale yellowish brown ventral part of body. The presence of black stripes on dorsal side differentiates this species from other known species of subgenus Ptilomera. It is only found in rocky, fast flowing streams and rivers that are not exposed to lot of sunlight. It has hair on middle legs that help insects resist strong current of streams. Water striders aregroup of insects adapted to life on surface of water, using surface tension to their advantage. Their presence serves as indicator water of water quality and also play important role in food chain in river ecosystem as they feed on mosquito larvae. Water striders have three pairs of legs. The front legs are relatively shorter than mid and hind legs and used to catch and hold prey. They possess needle-like mouth parts that are used for sucking the juice of prey. There are nearly 100 species of water striders found in India across different water bodies such as open ocean, ponds, pools, lakes, rivers, streams etc. With discovery of Ptilomera nagalanda, the number of species of water striders belonging to subgenus Ptilomera has increased to six in India. These includes Ptilomera agriodes found in peninsular India, Ptilomera laticaudata, northern and northeastern India, Ptilomera assamensis found in northeastern India, Pltilomera occidentalis from Uttarakhand and Ptilomera tigrina found in the Andaman islands.	<urn:uuid:878c650a-1a84-489d-b34d-6b85e37f4633>	3.203125	399	Knowledge Article	Science & Tech.	37.062332	95,577,845
The book on Heavy-Fermion Systems is a part of the Book series "Handbook of Metal Physics", each volume of which is written to facilitate the research of Ph.D. students, faculty and other researchers in a specific area. The Heavy-Fermions (sometimes known as Heavy-Electrons) is a loosely defined collection of intermetallic compounds containing rare-earth (mostly Ce) or actinide (mostly U) elements. These unusual names were given due to the large effective mass (100-1,000 times greater than the mass of a free electron) below a critical temperature. They have a variety of ground states including superconducting, antiferromagnetic, paramagnetic or semiconducting. Some display unusual magnetic properties such as magnetic quantum critical point and metamagnetism. This book is essentially a summary as well as a critical review of the theoretical and experimental work done on Heavy Fermions. Fri frakt for privatpersoner. Sendes innen 2‑5 virkedager.	<urn:uuid:3a6477cb-8651-4936-ba07-7d04477fccdf>	2.921875	211	Product Page	Science & Tech.	30.460493	95,577,872
Classification of changes in extreme heat over Southeastern Australia - Publication Type: - Journal Article - Procedia Computer Science, 2013, 20 pp. 148 - 155 - Issue Date: Over half of Australia's population lives in its southeastern quadrant. Temperature records for the 55-year period 1958-2013 indicate that hot summers have occurred increasingly since the 1990s with daily maximum temperatures reaching 10 oC above normal. The extreme nature of the change in monthly mean maximum temperatures (~1 to 1.5 oC above the long term mean) far exceeds the natural variability expected over a half century. Numerous maximum temperature records have been set and the extreme heat poses a major socioeconomic threat. This work examines changes in mean values of maximum daily temperatures for each summer month, in southeastern Australia. A 10-site dataset, for 1958-2013, was drawn and resampled to quantify temporal changes and uncertainty in decadal monthly maximum temperatures. Resampling methods documented the historical uniqueness of the maximum temperatures in recent decades. Results suggest strongly that, in recent decades, the maximum temperatures exceeding the upper quartile of the historical data is greater than expected by random chance. The findings confirm the regional nature of the warming. The increase in summer temperature is partly related to changes in atmospheric blocking. © 2013 The Authors. Published by Elsevier B.V. Please use this identifier to cite or link to this item:	<urn:uuid:9500917c-af7a-4e54-919e-d7759c1c233c>	3.1875	285	Academic Writing	Science & Tech.	29.628053	95,577,885
What are @property, @synthesize, @implementation, @interface in iphone programming? I am new to iPhone programming, and want to know: What are @property, @synthesize, @implementation, @interface in iPhone programming? - How does one compare one image to another to see if they are similar by a certain percentage, on the iPhone? - UIView performance: opaque, backgroundColor, clearsContextBeforeDrawing? - Saving Array to Plist file that contains Custom Objects iPhone - What is the most efficient way to sync Core Data with JSON API - Core Data Relationships: How to insert a new object into an entity and create a relationship to an existing object in another entity - View got hidden below UINavigationBar iOS 7 2 Solutions Collect From Internet About “What are @property, @synthesize, @implementation, @interface in iphone programming?” @property generates prototypes for getter and setter methods. You usually place it in an @interface block which is itself in a .h file. The @interface block is where you declare a object’s methods and attributes. @synthesize generates getter and setter methods. You usually place it in an @implementation block which is itself in a .m file. The @implementation block is where you write the code of the object’s methods. @property is an objective C directive that allows to generate accessors.here we can specify the name and type of the property @synthesize directive automatically generates setters and getters for us • interface : the interface of class is usually stored in .h file and defines instance variables and public methods • implementation : The implementation of a class is in .m file and usually contains the actual code of the methods - Mobile Safari/ iPhone Mail.app HTML design issues: prevent autolinking and styling auto-links (dates, addresses, etc.) - keeping a UIButton pressed(state selected/highlighted),until another button is pressed? - App crashes when user starts typing in UISearchBar - how to loop through elements of array of <UnsafeMutablePointer> in Swift - AFNetworking Cause Error while using XCTest in Xcode5 - How can I use String slicing subscripts in Swift 4? - How do I modify a GPUImageGaussianSelectiveBlurFilter to operate over a rectangle instead of a circle? - When are argument labels required in Swift? - How to add minutes to current time in swift - APNs push notification with macOS Sierra - How to make a map-like view that has a custom map image? - UIAlertController – add custom views to actionsheet - GCD pattern for chaining async operations while piping the results - Swift override protocol methods in sub classes - Deleting from UISearchController's filtered search results	<urn:uuid:7fa234a3-96a8-48f0-8293-e970b3e746f3>	2.984375	624	Q&A Forum	Software Dev.	25.286198	95,577,908
If you merge files containing keywords (see section Keyword substitution), you will normally get numerous conflicts during the merge, because the keywords are expanded differently in the revisions which you are merging. Therefore, you will often want to specify the `-kk' (see section Substitution modes) switch to the merge command line. By substituting just the name of the keyword, not the expanded value of that keyword, this option ensures that the revisions which you are merging will be the same as each other, and avoid spurious conflicts. For example, suppose you have a file like this: +---------+ _! 184.108.40.206 ! <- br1 / +---------+ / / +-----+ +-----+ ! 1.1 !----! 1.2 ! +-----+ +-----+ and your working directory is currently on the trunk (revision 1.2). Then you might get the following results from a merge: $ cat file1 key $Revision: 1.2 $ . . . $ cvs update -j br1 U file1 RCS file: /cvsroot/first-dir/file1,v retrieving revision 1.1 retrieving revision 220.127.116.11 Merging differences between 1.1 and 18.104.22.168 into file1 rcsmerge: warning: conflicts during merge $ cat file1 <<<<<<< file1 key $Revision: 1.2 $ ======= key $Revision: 22.214.171.124 $ >>>>>>> 126.96.36.199 . . . What happened was that the merge tried to merge the differences between 1.1 and 188.8.131.52 into your working directory. So, since the keyword changed from Revision: 1.1 to CVS tried to merge that change into your working directory, which conflicted with the fact that your working directory had contained Here is what happens if you had used `-kk': $ cat file1 key $Revision: 1.2 $ . . . $ cvs update -kk -j br1 U file1 RCS file: /cvsroot/first-dir/file1,v retrieving revision 1.1 retrieving revision 184.108.40.206 Merging differences between 1.1 and 220.127.116.11 into file1 $ cat file1 key $Revision$ . . . What is going on here is that revision 1.1 and 18.104.22.168 both expand as plain Revision, and therefore merging the changes between them into the working directory need not change anything. Therefore, there is no conflict. There is, however, one major caveat with using `-kk' on merges. Namely, it overrides whatever keyword expansion mode CVS would normally have used. In particular, this is a problem if the mode had been `-kb' for a binary file. Therefore, if your repository contains binary files, you will need to deal with the conflicts rather than using `-kk'.	<urn:uuid:d237f5e7-f652-494a-9f87-bcab457caa49>	2.578125	639	Documentation	Software Dev.	80.66981	95,577,911
T-SQL or Transact-SQL is a proprietary SQL extension (design query language). Additional features include high performance, maximum functionality, and greater globalization support. Transaction SQL is a Microsoft SQL Server process implemented. It is widely compatible with SQL-92, so you are familiar with the second SQL provider, probably feel at home with SQL. Transk-ss stored procedures are used to retrieve data or execute a question in the database. Transact- SQL stored procedure The stored procedure is a server-side routine. When you understand, they give you strength and give you a great advantage. Contrary to the user-defined functions (UDF), the stored procedure has allowed side effects. Because you can change the data in the table of actions and even change the appreciation of the object you can not worry about, it works. The protected procedure can be used as a security layer. To overcome access to the elements to perform something that can not be stored in the state. SQL Server 2008 supports a variety of stored procedures: a user-defined system and augmentation. You can create a stored procedure by the user and TSS or CLR. Below are some applications that can create transmission SQL General office productivity applications. - Graphical user interface (GUI) applications that are used to select tables and user data to select tables and data. - Databases of databases, where the data is mobilized from SQL Server adopted in different databases or distribution problems. Data storage in data obtained from online transaction processing systems (OLTP) and summary analysis to support decisions. More completely defined, do, SQL programming, is a mixture of several components, although integrated, component. Suppose you want to create an application and want to start designing and analyzing the database. And he developed the database in which he uses an authorized SQL statement or a tool for visual tool modeling. Later, you can request a complete set of configuration business in the table in your database running through Encoding in SQL. From here you can create: module processing and the processing module that supports the user interface using the storage method encrypted in SQL. As mentioned above, SQL Server 2008 developers can store and consume any type of data on any device, and make all those users who wish to create new applications: in SQL. One of the functions offered to the host so they can make relevant decisions closely related to the observation. These are the main characteristics: - Variants of variables - Union of workers - Change of modification - New types of date and time data - New date and time characteristics - Describe the statement - Classification of composition - A table with parameter values - Large types of users: Daratikon - Cost table of construction assistance - Type of organization of the type of data - DDL detects the repair - CLR large user-defined presentations SQL databases are a popular topic these days. For example, the data in Convert to SQL is more complex and is optimized for complex and large-scale technological problems. In order to learn this technology, great problems of comprehension and integral storage of data and mining conditions are also included. Some of the beginners who have knowledge of RDBMS can help some new concepts improve their accessibility. - Deependra is a Senior Developer with Microsoft technologies, currently working with Opteamix India business private solution. In My Free time, I write blogs and make technical youtube videos. Having the good understanding of Service-oriented architect, Designing microservices using domain driven design.	<urn:uuid:6b7331e9-2958-443c-98ca-9828cf4f902c>	3.125	717	Personal Blog	Software Dev.	27.000645	95,577,957
Plants rarely get sick in their natural environment. When the threat of infection arises, a quick decision is made about the necessary countermeasures. The course is set by a protein which forms complexes with its partner proteins for this purpose. Plant cell in defense against microbial pathogene attack: heterodimeric protein complexes of EDS1 (blue) with either SAG101 (green) or PAD4 (brown) govern which cells are sacrified (local cell death) and which are sensitised to prevent the infection from propagation. © MPI f. Plant Breeding Research/Stephan Wagner Jane Parker from the Max Planck Institute for Plant Breeding Research in Cologne and Karsten Niefind from the Institute of Biochemistry at the University of Cologne have, together with colleagues, determined the three-dimensional structure of such a key complex. These molecular close-ups will enable scientists to reach a better understanding of plant immunity in the near future. Like other organisms, plants defend themselves against attack from disease-causing microbes. Because these immune responses are associated with considerable stress and energy expenditure, the infected cells make very specific decisions about the actions actually required. To do this, they employ several layers of defence which come into force at different stages of pathogen infection, gradually ramping up the host immune response. Sometimes, this relies on a radical solution at the site of the infection and the plant sacrifices the infected cell by programmed cell death. Death, however, must be meticulously controlled. A rapidly administered ‘acute’ local defence response also usefully primes the remainder of the plant against subsequent attack. “Effector-triggered immunity” is one such line of defence. Here, plant immune receptors inside the cell recognise specific disease factors produced by a highly adapted pathogen. What happens after that depends on which complexes the mobile protein EDS1, moving between the cell nucleus and cytoplasm, forms with its partner proteins, PAD4 and SAG101. EDS1 sets the course of the immune response by forming distinct complexes – known as heterodimeric complexes – with its partners. The immune response varies according to the nature of the complex formed. The three proteins are structurally similar and the nature of each heterodimeric complex likely dictates the resistance output. “We would like to know how the plant resistance signalling system works and makes decisions in a dynamic way to confer resistance. Handling pathogen stress likely involves exquisite communication between different pathways ’” says Jane Parker, explaining her interest in the three proteins. Together with Jane Parker and Johannes Stuttmann from the Max Planck Institute for Plant Breeding Research and other colleagues, Karsten Niefind and Stephan Wagner from the University of Cologne determined the atomic structure of the EDS1-SAG101 complex by means of protein x-ray crystallography, and extrapolated a model for the EDS1-PAD4 complex from this three-dimensional structure. All three proteins have a domain at their N terminals with a α/β hydrolase fold. This fold is one of the most successful architectures in protein evolution. It also arises in a similar form in fat-splitting lipases and various other enzymes. “Naturally, we wanted to know whether EDS1 has a lipase activity on its own or in the heterodimeric complex, and whether EDS1 needs this lipase activity for its functions,” says Parker. “Surprisingly, the structure revealed to us that this is not the case, as the potentially active centre is completely shielded by a kind of cover. We also could not detect any lipase activity in the test tube.” What’s more: Parker and her colleagues showed that Arabidopsis plants, in which the putative catalytic centre of both EDS1 and PAD4 has been destroyed through mutations, are nonetheless fully competent in resistance to certain pathogens as the wild type proteins. So how does EDS1 accomplish its resistance signalling task, if not through catalytic activity? The x-ray structure of the EDS1/SAG101 heterodimer complex provides a valuable pointer here. EDS1 has a conspicuous protuberance or loop in its N terminal domain which slips into a matching cavity in SAG101 like a key in a lock. PAD4 has a similar cavity and can accommodate the same EDS1 loop. The Cologne-based scientists engineered mutations into these regions and in this way showed that the central task of the lipase-like domains is likely in the provision of these contact sites. Only when the cavity and protuberance are matched can the important C-terminal domains of both complex partners be brought into spatial proximity to create a new functional module. Without the lipase-like domains, there are no stable complexes, and without heterodimerised C-terminals there is no immune response! Intensive investigations are underway to find out how formation of the different EDS1 heterodimers in the cell proceeds and the precise role of each exclusive heterodimer. “The x-ray structure not only revealed to us the mechanism of heterodimerisation in the EDS1 protein family, it also shows us prominent surfaces and binding pockets which only exist in the dimers and will likely provide the key to understanding this important plant immunity mechanism,” explains Niefind.Contact Cell Host Microbe: Doi:10.1016/j.chom.2013.11.006 Prof. Dr. Jane Parker \| Max-Planck-Institute NYSCF researchers develop novel bioengineering technique for personalized bone grafts 18.07.2018 \| New York Stem Cell Foundation Pollen taxi for bacteria 18.07.2018 \| Technische Universität München For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 18.07.2018 \| Materials Sciences 18.07.2018 \| Life Sciences 18.07.2018 \| Health and Medicine	<urn:uuid:fa2fbb02-513a-4b3c-bca8-4fd75b0ce535>	3.515625	1,771	Content Listing	Science & Tech.	35.135928	95,577,960
Brown University researchers and collaborators from Tsinghua University in China have shown that nanoclusters made from boron and lanthanide elements form highly stable and symmetric structures with interesting magnetic properties. If your laptop or cell phone starts to feel warm after playing hours of video games or running too many apps at one time, those devices are actually doing their job. New experiments by researchers at the National Graphene Institute at the University of Manchester have shed more light on the gas flow through tiny, angstrom-sized channels with atomically flat walls. High-temperature desalination technologies can efficiently reduce the concentrations of a chemical element in seawater to make it an effective substitute for fresh water. Research into how the element boron evaporates could ... Boron nitride nanotubes are primed to become effective building blocks for next-generation composite and polymer materials based on a new discovery at Rice University—and a previous one. Cancer drops sparse chemical hints of its presence early on, but unfortunately, many of them are in a class of biochemicals that could not be detected thoroughly, until now. Physicists at MIPT and their British and Russian colleagues revealed the mechanisms leading to photocurrent in graphene under terahertz radiation. The paper published in Applied Physics Letters ends a long-lasting debate ... All electronic devices consist of billions of transistors, the key building block invented in Bell Labs in the late 1940s. Early transistors were as large as one centimeter, but now measure about 14 nanometers. There has ... Perfection is not everything, according to an international team of researchers whose 2-D materials study shows that defects can enhance a material's physical, electrochemical, magnetic, energy and catalytic properties. A KAUST chemical reactor that operates at extremely high temperatures could improve the efficiency and economy of a commonly used process in the semiconductor industry, with benefits for Saudi Arabia's chemical industry.	<urn:uuid:b13b6684-ff3a-4815-b8e9-bc32c06dbe5d>	2.875	402	Content Listing	Science & Tech.	21.968927	95,577,989
Hydrogen could be the ideal fuel: Whether used to make electricity in a fuel cell or burned to make heat, the only byproduct is water; there is no climate-altering carbon dioxide. Like gasoline, hydrogen could also be used to store energy. Hydrogen is usually produced by separating water with electrical power. And although the water supply is essentially limitless, a major roadblock to a future "hydrogen economy" is the need for platinum or other expensive noble metals in the water-splitting devices. Bathed in simulated sunlight, this photoelectrolysis cell in the lab of Song Jin, a professor of chemistry at the University of Wisconsin-Madison, splits water into hydrogen and oxygen using a catalyst made of the abundant elements cobalt, phosphorus and sulfur. Credit: David Tenenbaum/University of Wisconsin-Madison Noble metals resist oxidation and include many of the precious metals, such as platinum, palladium, iridium and gold. "In the hydrogen evolution reaction, the whole game is coming up with inexpensive alternatives to platinum and the other noble metals," says Song Jin, a professor of chemistry at the University of Wisconsin-Madison. In the online edition of Nature Materials that appears today, Jin's research team reports a hydrogen-making catalyst containing phosphorus and sulfur -- both common elements -- and cobalt, a metal that is 1,000 times cheaper than platinum. Catalysts reduce the energy needed to start a chemical reaction. The new catalyst is almost as efficient as platinum and likely shows the highest catalytic performance among the non-noble metal catalysts reported so far, Jin reports. The advance emerges from a long line of research in Jin's lab that has focused on the use of iron pyrite (fool's gold) and other inexpensive, abundant materials for energy transformation. Jin and his students Miguel Cabán-Acevedo and Michael Stone discovered the new high-performance catalyst by replacing iron to make cobalt pyrite, and then added phosphorus. Although electricity is the usual energy source for splitting water into hydrogen and oxygen, "there is a lot of interest in using sunlight to split water directly," Jin says. The new catalyst can also work with the energy from sunlight, Jin says. "We have demonstrated a proof-of-concept device for using this cobalt catalyst and solar energy to drive hydrogen generation, which also has the best reported efficiency for systems that rely only on inexpensive catalysts and materials to convert directly from sunlight to hydrogen." Many researchers are looking to find a cheaper replacement for platinum, Jin says. "Because this new catalyst is so much better and so close to the performance of platinum, we immediately asked WARF (the Wisconsin Alumni Research Foundation) to file a provisional patent, which they did in just two weeks." Many questions remain about a catalyst that has only been tested in the lab, Jin says. "One needs to consider the cost of the catalyst compared to the whole system. There's always a tradeoff: If you want to build the best electrolyzer, you still want to use platinum. If you are able to sacrifice a bit of performance and are more concerned about the cost and scalability, you may use this new cobalt catalyst." Strategies to replace a significant portion of fossil fuels with renewable solar energy must be carried out on a huge scale if they are to affect the climate crisis, Jin says. "If you want to make a dent in the global warming problem, you have to think big. Whether we imagine making hydrogen from electricity, or directly from sunlight, we need square miles of devices to evolve that much hydrogen. And there might not be enough platinum to do that." The collaborative team included Professor J.R. Schmidt, a theoretical chemist at UW-Madison, and electrical engineering Professor Jr-Hau He and his students from King Abdullah University of Science and Technology in Saudi Arabia. The U.S. Department of Energy provided major funding for the study. Song Jin \| EurekAlert! Scientists uncover the role of a protein in production & survival of myelin-forming cells 19.07.2018 \| Advanced Science Research Center, GC/CUNY NYSCF researchers develop novel bioengineering technique for personalized bone grafts 18.07.2018 \| New York Stem Cell Foundation A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Power and Electrical Engineering 20.07.2018 \| Information Technology 20.07.2018 \| Materials Sciences	<urn:uuid:cbc1b5ab-720d-45ce-a47d-959b6c7c05a7>	4.125	1,402	Content Listing	Science & Tech.	35.272885	95,577,992
Complex waves generate flow patterns that could be used to manipulate floating objects or explain rips at the beach Physicists at The Australian National University (ANU) have created a tractor beam on water, providing a radical new technique that could confine oil spills, manipulate floating objects or explain rips at the beach. The group, led by Professor Michael Shats discovered they can control water flow patterns with simple wave generators, enabling them to move floating objects at will. "We have figured out a way of creating waves that can force a floating object to move against the direction of the wave," said Dr Horst Punzmann, from the Research School of Physics and Engineering, who led the project. "No one could have guessed this result," he said. The new technique gives scientists a way of controlling things adrift on water in a way they have never had before, resembling sci-fi tractor beams that draw in objects. Using a ping-pong ball in a wave tank, the group worked out the size and frequency of the waves required to move the ball in whichever direction they want. Advanced particle tracking tools, developed by team members Dr Nicolas Francois and Dr Hua Xia, revealed that the waves generate currents on the surface of the water. "We found that above a certain height, these complex three-dimensional waves generate flow patterns on the surface of the water," Professor Shats said. "The tractor beam is just one of the patterns, they can be inward flows, outward flows or vortices." The team also experimented with different shaped plungers to generate different swirling flow patterns. As yet no mathematical theory can explain these experiments, Dr Punzmann said. "It's one of the great unresolved problems, yet anyone in the bathtub can reproduce it. We were very surprised no one had described it before." Michael Shats \| Eurek Alert! Computer model predicts how fracturing metallic glass releases energy at the atomic level 20.07.2018 \| American Institute of Physics What happens when we heat the atomic lattice of a magnet all of a sudden? 18.07.2018 \| Forschungsverbund Berlin A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Power and Electrical Engineering 20.07.2018 \| Information Technology 20.07.2018 \| Materials Sciences	<urn:uuid:ebe0250e-2ed2-421f-ad01-be32253d3c29>	3.328125	963	Content Listing	Science & Tech.	41.843211	95,577,993
Titel: Relativity in Rotating Frames: Relativistic Physics in Rotating Reference Frames Relativistic Physics in Rotating Reference Frames. 'Fundamental Theories of Physics'. Herausgegeben von G. Rizzi, Matteo Luca Ruggiero SPRINGER VERLAG GMBH 31. Dezember 2003 - gebunden - 456 Seiten Even if the subject is a long-standing one, this is the first monograph on this field. On the one hand, this book is intended to give a rather wide review on this field, both in a historical and pedagogical perspective; on the other hand, it aims at critically re-examining and discussing the most controversial issues. For instance, according to some authors the celebrated Sagnac effect is a disproval of the theory of relativity applied to rotating frames; according to others, it is an astonishing experimental evidence of the relativistic theory. In order to give the reader a deeper insight into this research field, the contributing authors discuss their opinions on the main subjects in an enthralling virtual round table: in this way, the reader can get a direct comparison of the various viewpoints on the most controversial and interesting topics. This is particularly expedient, since the differences in the various approaches are often based upon subtleties that can be understood only by a direct comparison of the underlying hypotheses. I Historical Papers.- 1 Uniform Rotation of Rigid Bodies and the Theory of Relativity.- 2 The existence of the luminiferous ether demonstrated by means of the effect of a relative ether wind in an uniformly rotating interferometer.- II Papers.- 1 The Sagnac Effect in the Global Positioning System.- 2 Space, Time and Coordinates in a Rotating World.- 3 The Hypothesis of Locality and its Limitations.- 4 Sagnac effect: end of the mystery.- 5 Synchronization and desynchronization on rotating platforms.- 6 Toward a Consistent Theory of Relativistic Rotation.- 7 Elementary Considerations of the Time and Geometry of Rotating Reference Frames.- 8 Local and Global Anisotropy in the Speed of Light.- 9 Isotropy of the velocity of light and the Sagnac effect.- 10 The relativistic Sagnac effect: two derivations.- 11 Inertial forces: the special relativistic assessment.- 12 Eppur, si muove!.- 13 Does anything happen on a rotating disk?.- 14 Proper co-ordinates of non-inertial observers and rotation.- 15 Space geometry in rotating reference frames: A historical appraisal.- 16 Quantum Physics in Inertial and Gravitational Fields.- 17 Quantum Mechanics in a Rotating Frame.- 18 On rotating spacetimes.- III Round Table.- I Dialogue on the velocity of light in a rotating frame.- II Dialogue on synchronization and Sagnac effect.- III Dialogue on the measurement of lengths in a rotating frame.- IV Dialogue on the Brillet-Hall experiment.- V Dialogue on quantum effects in rotating systems.- VI Dialogue on non uniform motions and other details about Klauber's and Selleri's challenges. Foundations of Physics, Vol. 34, No. 8, August 2004 (© 2004) Relativity in Rotating Frames. Relativistic Physics in Rotating Reference Frames. Edited by G.Rizzi and M.L.Ruggiero, (Fundamental Theories of Physics 135), 452 pp., $193.00. ISBN 1-4020-1805-3. Soon after Einstein's destruction of absolute simultaneity and Minkowski's formulation of special relativity, the problem of the relativistic description of extended bodies in rotating reference frames led to Ehrenfest's paradox with the subsequent Einstein's answer and to an endless still on going debate about the instantaneous space and the geometry of a rotating disk and the associated Sagnac effect. As emphasized by Stachel in the Preface of this book, edited by G.Rizzi and M.L.Ruggiero and composed of invited contributions, from both "traditionalists" and "heretics", the existence of a structural difference between translations and rotations goes back to Aristotle. Only with Newton translations with constant velocity where privileged with respect to other types of motion through the introduction of the notion of inertial reference frame and the law of inertia. This notion survived in Einstein's formulation of special relativity, but at the price of loosing the concept of instantaneous three-space: only the notion of being space-like with respect to an observer is well de.ned. Since a relativistic, either inertial or no inertial, observer has no "absolute present", the description of extended objects becomes a non-trivial problem. Given only the postulates of special relativity, namely the constancy and isotropy of the round-trip velocity of light involving only one observer and one clock, there is no unique de.nition of synchronization of clocks, of one-way velocity of light and of spatial distance in an instantaneous three-space. We must make some convention, for instance Einstein's convention of simultaneity in inertial frames implying an isotropic one-way velocity of light and "equal time" hyper-planes, regarding one of these notions to have the other two de.ned. 0015-9018/04/0800-1281/0 © 2004 Plenum Publishing Corporation 1282 Book Review As a consequence, since in non-inertial frames no convention, globally valid like Einstein's one in inertial frames, is known, different conventions lead to different viewpoints especially in connection with non-inertial uniformly rotating frames and to the necessity of a still lacking interpretation of their equivalence. This so deeply non-Newtonian framework explains why extended objects like the uniformly rotating disk, which presents no conceptual difficulty at the Newtonian level, give rise to a so controversial and non-unique picture at the relativistic level. Grøn's historical contribution shows how many, often contradictory, viewpoints have been developed in 90 years. This book is really welcome because it gives a snapshot of the existing spectrum of interpretations regarding rotating coordinate systems (Dieks, Bel, Nikolic, de Felice), the locality hypothesis (Mashhoon), inertial forces (Bini, Jantzen), the anisotropy of the velocity of light in rotating frames and the Sagnac effect (Klauber, Selleri, Sera.ni, Rizzi, Ruggiero, Weber, Sorge, Pascual-Sanchez, Vicente), what is the "space of a rotating disk" and how to de.ne length measurements in rotating frames (Rizzi, Ruggiero, Tartaglia, Grøn, Klauber, Nikolic), quantum mechanics in rotating frames and the gravitational .eld (Papini, Anandan, Suzuki). Only Mach's principle is absent! The absence of agreement among the various interpretations, nicely made explicit through six virtual dialogues at the end of the book, is made more acute by the contributions of Rizzi and Sera.ni on the freedom in the choice of the notion of simultaneity in rotating frames and of Ashby on the relevance of the Sagnac effect in the Global Positioning System especially after the developments of modern technology oriented to space navigation and requiring the synchronization of the now existing ultra-precise atomic clocks till the order 1/c3. In conclusion, it is hoped that this book will be a stimulus to start a fresh search of the missing elements to arrive at a relativistic description of extended objects in arbitrary non-inertial frames. Such a description should include Maxwell equations and should lead to a well-posed Cauchy problem allowing us to get control on the energy balance of every physical system in a non-inertial reference frame.	<urn:uuid:453825d9-2f23-46a5-afc8-7d5dffd8cfc4>	2.859375	1,648	Academic Writing	Science & Tech.	33.715586	95,578,008
"Collection" is an interface where the interfaces Set, List and Queue extend from. These in turn are implemented by the different classes, e.g. the interface Set by HashSet. "Collections" is a class that holds all kind of static methods. For example Collections.sort(List<T> list) that will sort a list or its overload Collections.sort(List<T> list, Comparator<? super T> c). "Map"s are also a collection and thus part of the Collection Framework, but "Map" simply does not extend from "Collection". The Collection Framework is a help for the programmer to make use of well defined, loose coupled and high cohesive classes and interfaces that have been tested to be "perfect". This should give you a first overview. Good luck. Ciao,<br /> Tommaso<br /> <br />~~~*~<br />There are 10 types of people, those who understand binary and those who don't. His brain is the size of a cherry pit! About the size of this ad:	<urn:uuid:02c19ae3-a9ab-45f5-ada7-630749d00360>	3	230	Comment Section	Software Dev.	69.637083	95,578,031
Having said that, Should your plan doesn’t trust in dynamic functions and that you choose to originate from the static entire world (especially, from the Java way of thinking), not catching these kinds of "mistakes" at compile time could be stunning. An assignment operation is really a procedure in critical programming where distinct values are affiliated with a specific variable name as time passes. The program, in this sort of design, operates by altering its point out working with successive assignment statements. Not the answer you're looking for? Look through other inquiries tagged c++ arrays programming-languages syntax or question your individual question. questioned It is important to grasp the logic behind the kind checker: It is just a compile-time Check out, so by definition, the sort checker isn't conscious of any sort of runtime metaprogramming that you choose to do. but Imagine if the array is currently initialized And that i want to wholly exchange the values of The weather in that array in a single line Firstly, upload your accounts assignment or homework on our Internet site or mail us on our email ID i.e. firstname.lastname@example.org. Our pro panel will endure it meticulously and as soon as They can be 100% positive of the answer, we will get again with correct value estimate. system phone calls are resolved at compile time, this means that if a method isn't declared on a category, the compiler will throw an mistake the assignment is usually a variable declaration and also a is really a map literal and T provides a no-arg constructor as well as a property for each from the map keys This new ebook is chock-full of programming project Concepts with Every project notion featuring a issues amount (from one – ten), comprehensive description on the project, professional tricks for how to consider tackling the Discover More project in the common non-platform distinct way and strategies for earning the project a lot more Highly developed. Find out how to More Help build vectors in R Learn the way to create variables Find out about integer, double, reasonable, character along with other styles in R Learn the way to produce a while() loop plus a for() loop in R Learn how to construct and use matrices in R Discover the matrix() function, discover rbind() and cbind() Learn how to put in offers in R Learn how to personalize R see this studio to fit your Choices Comprehend the Law of enormous Quantities Have an understanding of the traditional distribution Exercise dealing with statistical knowledge in R Observe working with economical info in R Apply working with sporting activities details in R Specifications No prior know-how or knowledge necessary. Just a enthusiasm to achieve success! The results of the assertion is incredibly distinct from what you'll get in Java. find more information If the assertion is real, then nothing takes place. If the assertion is fake, then it provides a visual illustration of the value of each sub-expressions on the expression remaining asserted. For example: In the Try out ENDTRY eventually , you will be contacting finally the student class process i.e Screen method of scholar . This area consists of weasel terms: obscure phrasing That always accompanies biased or unverifiable details. Such statements must be clarified or taken off. (Might 2017) The material is "optional" in the feeling that it is not desired for the homeworks or subsequent week's Test, however it is nevertheless incredibly hugely encouraged to higher realize why the course (together with Parts B and C) handles what it does and, hopefully, will change the way you check out software program without end.	<urn:uuid:e825b122-a2e3-4372-a04c-5118a7e76f3c>	2.8125	734	Tutorial	Software Dev.	37.700905	95,578,038
British are docile, Spanish are revolutionary: How ANTS show national characteristics Perhaps it's their fiery Latino temperament. Or maybe it's a legacy from the civil war. According to a new study, Spanish worker ants are hot-headed revolutionaries compared to their docile British counterparts. Scientists have discovered that the Iberian insects are ruthless in selecting their queens - and will bully and assassinate rivals in order to make sure their favoured female leader gets the top job in the nest. The same worker ants in Britain, in contrast, refuse to get involved in politics - and will loyally follow any female that sets herself up as a matriarch. Different temperaments: Spanish twig ants were found to be aggressive and keen to get their own way but British twig ants were more docile The discovery that British and Spanish workers have completely different attitudes to royalty comes from a four year study into colonies of leaf ants. Dr Robert Hammond, who led the study at Leicester University, said: 'Worker ants are known to be important players in various arguments that happen within the colony, but this is the first time worker ants have been shown to be so influential over which queens reproduce. 'Also, the contrast in worker power between the aggressive Spanish twig ant workers and the apathetic twig ant workers found in the UK and elsewhere is intriguing. 'The role of workers has been overlooked in the argument over who determines which queens reproduce. Also, a particular species is often thought to have fixed social organisation. 'This work shows that species can vary in fundamental aspects of how their societies are organised.' Twig ants are common in Britain - but rarely venture into gardens or homes. They live in colonies of up to 200 ants inside decaying twigs and branches on woodland floors. Past studies have shown that British, French and German twig ant colonies can have up to 10 queens at any one time. However, their Spanish cousins are made up of single family units with just one fertile female. The researchers collected 22 colonies of ants from Spain and rehoused in them in a laboratory. Over four years, they monitored the behaviour of the worker ants - looking out for evidence that they bite, drag or attack potential queens. The study, published in the journal Proceedings of the Royal Society B, showed that Spanish ants were far more aggressive towards the queens than British ants. Queens who were persistently attacked and harangued by the workers were far less likely to go on to be egg layers - suggesting that the workers 'decide' which females get to rule the nest. The Spanish workers also showed a preference for their mothers, attacking them far less than other potential queens. 'We found evidence that workers do indeed hold the power - and like revolting peasants - the masses are ferocious with workers beating up and even killing all but one queen who they preferentially groom and who ends up reproducing,' Dr Hammond added. Ants have a complex social structure. The queens lay eggs in the spring which hatch into grubs who are cared for by the infertile female worker ants throughout the summer and winter. The grubs turn into adult workers, queens and males the following summer. The queens and males live the nest to mate before the queens go off to find a new nest - or in the case of British twig ants - return to their old home to lay eggs alongside the existing queens. The researchers are unsure why the Spanish ants are more fiery tempered than their British relatives. 'It could be that Spanish twig ants are only found high up in mountains in small patches so it may benefit the colonies if queens have to find new nests,' Dr Hammond added. Most watched News videos - Courageous woman hides victim from kidnappers till cops arrive - CVS manager calls cops on black woman trying to use coupon - The streets of Alcudia in Mallorca are flooded by mini-tsunami - Brave lion cub forced to jump into raging river to follow mother - Model Annabelle Neilson walks the catwalk in 2010 fashion show - 'She is a remainer': Rees-Mogg launches attack on PM - Beach in Ciutadella Menorca hit by mini-tsunami 'rissaga' - 'Trump told me I should sue the EU': Prime Minister Theresa May - Love Island TEASER: Georgia gets anxious as she could be kicked off - Trump says Queen is 'a beautiful woman both inside and out' - Emmanuel Macron 'dabs' with French players Mendy and Pogba - Driver who punched mother during road rage insists he's a victim No comments have so far been submitted. Why not be the first to send us your thoughts, or debate this issue live on our message boards. We are no longer accepting comments on this article.	<urn:uuid:0c799d97-cfd0-44fe-b33e-b0f16090eac3>	3.0625	999	Truncated	Science & Tech.	41.028177	95,578,042
A modest new lab at the Rosenstiel School is the first of its kind to tackle the global problem of climate change impacts on corals. Fully operational this month, this new lab has begun to study how corals respond to the combined stress of greenhouse warming and ocean acidification. The lab is the first to maintain corals under precisely controlled temperature and carbon dioxide conditions while exposing them to natural light conditions. Using two Caribbean coral species as its study subjects, Montastraea faveolata (mountainous star coral) and Porites furcata (finger coral), the research team will study how the world's increasingly acidic oceans (caused by increasing atmospheric carbon dioxide) affect these corals when accompanied with increasing ocean temperatures as well. “I was interested in stressing corals at differing levels of carbon dioxide and temperatures much like they would experience in the next 50 to 100 years to see if skeletal development is affected,” said Dr. Chris Langdon, one of the lab's creators and the scientist who developed a similar lab at the University of Hawaii studying corals at varying carbon dioxide changes alone. Dr. Andrew Baker, co-creator and also a Rosenstiel School faculty, has spent much of his career looking at climate change impacts on corals and has geared his perspective towards understanding whether corals can adapt to any of these changes. “I's clear that corals of the future will see much warmer, more acidic oceans than we have now,” Baker said. “By mimicking these same changes in the laboratory we get a much clearer idea of how these corals will respond.” The National Science Foundation, the Packard Foundation, Conservation International and the Wildlife Conservation Society have made the new lab possible through their funding of research and the actual facilities and instrumentation necessary to ensure precise monitoring. Located at the school's hatchery on Virginia Key, the lab provides research opportunities for a dozen faculty, staff, and students. Rosenstiel School is part of the University of Miami and, since its founding in the 1940s, has grown into one of the world's premier marine and atmospheric research institutions.Media Contact: Ivy F. Kupec \| EurekAlert! New research calculates capacity of North American forests to sequester carbon 16.07.2018 \| University of California - Santa Cruz Scientists discover Earth's youngest banded iron formation in western China 12.07.2018 \| University of Alberta For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 16.07.2018 \| Physics and Astronomy 16.07.2018 \| Life Sciences 16.07.2018 \| Earth Sciences	<urn:uuid:6ae8a6b6-27bb-4dfb-b73a-574a73c71a07>	3.578125	1,084	Content Listing	Science & Tech.	38.051677	95,578,048
The gray jay is a year-round resident of the boreal forest. It survives the long cold winters at high latitudes by storing food items throughout the fall. They rely on stored food throughout the winter, when food is scarce. Many animals store or cache food, but the gray jay is unusual in that it stores perishable food that may spoil in warm temperatures and it relies on the caches remaining viable for long periods of time. Gray jays are also special because they begin to nest in March, among the earliest birds in Alaska. They begin laying eggs when there is still snow on the ground and temperatures may plunge to -40 degrees Fahrenheit. Growing evidence suggests that the warming climate may be decreasing food available to gray jays in the winter. This is leading to a decline in their ability to raise young. Park biologists are working with partners at the University of Guelph and University of Washington to collect data on this issue. They aim to fill critical gaps in knowledge about gray jays' year-round requirements and examine how a warming climate may impact the persistence of gray jays in Alaska’s boreal forests.	<urn:uuid:41f26a08-f9f1-434a-980e-01299371d848>	4.28125	230	Knowledge Article	Science & Tech.	51.292545	95,578,050
+44 1803 865913 By: Tran Anh Duc(Editor), Yang Chang Man(Editor), Lanna Cheng(Editor), Peter KL Ng(Foreword By) 334 pages, colour photos, b/w line drawings An introduction for all families of waterbugs within its area, and a working tool targeted both at students and at the general public fascinated with the biodiversity of the tropics. Waterbugs are members of the insect order Hemiptera and occur in both freshwater and marine environments. The book is written by expert entomologists, excellently produced by the Lee Kong Chian Natural History Museum and richly illustrated throughout with numerous colour photographs and line drawings. There are currently no reviews for this book. Be the first to review this book! Your orders support book donation projects I have always been MOST impressed by the efficiency, courtesy, integrity and professionalism of NHBS! Search and browse over 110,000 wildlife and science products Multi-currency. Secure worldwide shipping Wildlife, science and conservation since 1985	<urn:uuid:f8992534-183d-41db-9ffc-3ada5d70ae2b>	2.78125	216	Product Page	Science & Tech.	35.330943	95,578,076
Authors: Yuanjie Huang As is known, the piezoelectric effect and electrostrictive effect exist in some ceramics and dielectric materials. However, such effect has never been discovered in conventional metals before. Here, strain-induced electric effect in conventional metals, named after Professor Yuheng Zhang, was first uncovered theoretically in this work. This effect gives several interesting and surprising predictions for metals as follows: 1) conduction electrons in metals no longer obey Einstein diffusion relation but satisfy a new relation given in this work; 2) a metal with strain gradients at a uniform temperature is no longer an equal-electric potential body even without any external electromagnetic disturbances; 3) a metal possessing non-uniform strains may behave as an ideal p-n junction, blocking electric current completely if the applied reverse-biased voltage is not large enough; 4) the long-standing physical puzzle for thermoelectric effect of metals, the positive sigh of Seebeck coefficient for metals, is unraveled by means of Yuheng Zhang coefficient, a newly found vital coefficient induced by both thermal expansion and Yuheng Zhang effect; 5) a notable electric voltage maintains across the shock wave front in metals; 6) an electric voltage appears between two phases when phase transition happens for metals, offering a new probe to detect phase transions. In all, this effect may expand one's fundamental knowledge on metals and find applications in various fields. Comments: 21 Pages. [v1] 2017-07-10 19:13:14 Unique-IP document downloads: 77 times Vixra.org is a pre-print repository rather than a journal. Articles hosted may not yet have been verified by peer-review and should be treated as preliminary. In particular, anything that appears to include financial or legal advice or proposed medical treatments should be treated with due caution. Vixra.org will not be responsible for any consequences of actions that result from any form of use of any documents on this website. Add your own feedback and questions here: You are equally welcome to be positive or negative about any paper but please be polite. If you are being critical you must mention at least one specific error, otherwise your comment will be deleted as unhelpful.	<urn:uuid:4d1fe5a4-e3bb-467e-83a5-9619149ec4d2>	2.734375	460	Knowledge Article	Science & Tech.	27.515414	95,578,102
Image courtesy of Fang-Yi Chu and Alexandra Zidovska, Department of Physics, New York UniversityA team of scientists has revealed an internal clock within live human cells, a finding that creates new opportunities for understanding the building blocks of life and the onset of disease. "Previously, a precise point of a cell in its life cycle could only be determined by studying dead cells," explains Alexandra Zidovska, an assistant professor of physics at New York University and the senior author of research, which appears in the latest issue of the journal Proceedings of the National Academy of Sciences (PNAS). "However, with this discovery, which shows that the nucleus exhibits rapid fluctuations that decrease during the life cycle of the cell, we can enhance our knowledge of both healthy and diseased human cells." The study, which also included Fang-Yi Chu, an NYU doctoral candidate, and Shannon Haley, an NYU undergraduate, sought to expand our understanding of the cell nucleus during the cell cycle. It's long been established that the shape and size of the cell nucleus change dramatically during a cell's life. Unknown, however, was whether or not the nucleus changes its shape over short periods of time. This was largely due to technical limitations of carrying out such measurements in living cells. To capture this dynamic, the scientists used a state-of-the-art fluorescent microscope that enables them to see extremely small and very fast shape changes of the cell nucleus in living cells. The researchers discovered that the human cell nucleus has a previously undetected type of motion: its nuclear envelope flickers, or fluctuates, over a period of a few seconds. Notably, the amplitude of these changes in shape decreases over time during the cell cycle. Moreover, this motion marks the first physical feature that systematically changes with the cell cycle. "Therefore, this process can serve as an internal clock of the cell, telling you at what stage in the cell cycle the cell is," explains Zidovska. "We know that structural and functional errors of the nuclear envelope lead to a large number of developmental and inherited disorders, such as cardiomyopathy, muscular dystrophy, and cancer. Illuminating the mechanics of nuclear shape fluctuations might contribute to efforts to understand the nuclear envelope in health and disease." The research was supported by a grant from the National Institutes of Health (R00-GM104152). Like this article? Click here to subscribe to free newsletters from Lab Manager	<urn:uuid:0084cf07-9d28-4d1a-ae23-8c223627898c>	3.421875	502	News Article	Science & Tech.	31.658382	95,578,105
When relatively small amounts of magnesium burns, the fires are extinguished using commercially available dry powder. Why might this fire rekindle days later as someone tries to remove the residue with water? What chemical process is involved here?© BrainMass Inc. brainmass.com July 22, 2018, 1:13 am ad1c9bdddf Magnesium fires are Class D fires. Such fires are put out by dry powders that contain sodium chloride. Water reacts slowly with Mg to form Mg(OH)2 and H2 gas. But this ... The reasons for the rekindling of Magnesium fires when dry powders are used is discussed.	<urn:uuid:a7bf8ea4-75f2-447d-bb44-19fb5f269bc2>	3.46875	135	Truncated	Science & Tech.	65.18918	95,578,118
HTML table with thead, tbody and tfoot elements: <table border="1"> <thead> <tr> <th>Month</th> <th>Savings</th> </tr> </thead> <tfoot> <tr> <td>Sum</td> <td>$180</td> </tr> </tfoot> <tbody><tr> <td>January</td> <td>$100</td> </tr> <tr> <td>February</td> <td>$80</td> </tr> <Tbody> tag only partly supported by all major browsers. <Tbody> tag form the body (the body). The label for combining HTML table body content. thead element is used for HTML table header content group, and tfoot element for HTML table table Note (footer) content are grouped. NOTE: If you use the thead, tfoot and tbody elements, you must use all elements. Their order of appearance are: thead, tfoot, tbody, so the browser can receive all the data presented before the footer. You must use these tags within the table element. Tip: By default, these elements will not affect the layout table. However, you can use CSS to make these elements affect the table's appearance. thead, tfoot tbody elements and gives you the ability to group table rows. When you create a table, you might want to have a header row, some rows with data, and a total at the bottom line. This division allows browsers have the ability to support independent of the table header and footer text scrolling table. When long tables are printed, the table headers and footers can be printed on each page that contains table data. NOTE: <thead> interior must have <tr> tag! NOTE: <thead>, <tbody> and <tfoot> seldom used, because of bad browser support. We expect that this situation will change in future versions of XHTML. If you are using Internet Explorer 5.0 or later browser, you can view a tutorial in our XML example . \|align\|\|Alignment is defined tbody element content.\| \|char\|\|character\|\|According to the provisions of which character to align text.\| \|charoff\|\|number\|\|The provisions of an offset alignment character.\| \|valign\|\|Predetermined vertical alignment tbody element content.\| <tbody> tag supports HTML in the global properties . <tbody> tag supports HTML in the event properties .	<urn:uuid:e66f2d35-9ee3-40e4-8304-02984fc140a3>	3.21875	540	Documentation	Software Dev.	64.397119	95,578,124
+44 1803 865913 Environment, Ninth Edition weaves the central themes of Systems and... By: Peter H Raven, Linda R Berg and David M Hassenzahl Offering a more concise resource for environmental scientists, the seventh edition explores important environmental issues and shows how to apply this information on the job. It focuses on a systems approach, presenting a framework for thinking about environmental science. The recurring theme of global climate change as a system is integrated throughout the chapters, uncovering both the positive and negative roles that people play in that system. Environmental scientists will also benefit from the revised art program. New photos and illustrations help reinforce concepts and make the material come to life. There are currently no reviews for this book. Be the first to review this book! Your orders support book donation projects I have never been so pleased with the quality of service. Search and browse over 110,000 wildlife and science products Multi-currency. Secure worldwide shipping Wildlife, science and conservation since 1985	<urn:uuid:08932382-dbe0-40cd-b2c4-568c82357e56>	2.671875	206	Product Page	Science & Tech.	39.539286	95,578,130
Radiometric dating using isotopes Sexchatroulette with girls free Potassium–argon dating, abbreviated K–Ar dating, is a radiometric dating method used in geochronology and archaeology.It is based on measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar).Before 1955, ages for the Earth based on uranium/thorium/lead ratios were generally about a billion years younger than the currently popular 4.5 billion years. old Earth is reviewed and deficiencies of the uranium/lead method are discussed.The basic theory of radiometric dating is briefly reviewed.As we pointed out in these two articles, radiometric dates are based on known rates of radioactivity, a phenomenon that is rooted in fundamental laws of physics and follows simple mathematical formulas.Dating schemes based on rates of radioactivity have been refined and scrutinized for several decades.The age of the fossil must be determined so it can be compared to other fossil species from the same time period.Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms. By comparing fossils of different primate species, scientists can examine how features changed and how primates evolved through time.The amount of Argon sublimation that occurs is a function of the purity of the sample, the composition of the mother material, and a number of other factors.These factors introduce error limits on the upper and lower bounds of dating, so that final determination of age is reliant on the environmental factors during formation, melting, and exposure to decreased pressure and/or open-air.Some evidence is also presented to show that radiometric results that are in agreement with the accepted geological time scale are selectively published in preference to those results that are not in agreement.The geological time scale and an age for the Earth of 4.5 b.y. Potassium is a common element found in many materials, such as micas, clay minerals, tephra, and evaporites.	<urn:uuid:af487b48-9f0e-4027-bfd5-3d0a5f48e0aa>	3.484375	410	Spam / Ads	Science & Tech.	28.342202	95,578,152
Tropical cyclones are not too common in the Arabian Sea, but tropical cyclone 01A, now renamed Ashobaa, formed this week. NASA/JAXA's Global Precipitation Measurement or GPM core satellite flew over Ashobaa and gathered data that provided a 3-D look at the rainfall in the storm. The GPM core observatory satellite flew over Ashobaa on the morning of June 8 at 0811 UTC (4:11 a.m. EDT). Tropical cyclone Ashobaa had sustained wind speeds of about 40 knots (46 mph) when the satellite passed overhead. On June 9 at 0900 UTC (5 a.m. EDT), tropical cyclone Ashobaa had maximum sustained winds near 50 knots (57.5 mph/92.6 kph). Ashobaa was centered near 20.7 north latitude and 64.1 east longitude, about 290 nautical miles (333.7 miles/ 537.1 km) south-southwest of Karachi, Pakistan. Ashobaa is moving west-northwest at 8 knots (9.2 mph/14.8 kph). Satellite data on June 9 showed that the storm is tightly wrapped, although elongated as clouds and showers are being pushed to the west because of persistent moderate easterly wind shear. The Joint Typhoon Warning Center (JTWC) predicts that tropical cyclone Ashobaa will become more powerful and have winds of 65 knots (about 75 mph) by June 10 as it moves through warm sea surface temperatures. Ashobaa is then predicted to weaken as dry stable air is expected to affect the system. It is forecast to turn west where it expected to make landfall on June 12 near Ras al Hadd, a village in the Ash Sharqiyah district in Oman. As Ashobaa continues curving to the west in the Arabian Sea, it is generating rough surf along the coasts of Oman, southeastern Iran and Pakistan. GPM's Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments measured rain falling at a rate of over 60 mm (2.3 inches) per hour in strong thunderstorms southwest of the storm's center of circulation. At NASA's Goddard Space Flight Center in Greenbelt, Md., a 3-D view was constructed using data from DPR Ku band radar data. The 3-D view of GPM revealed Ashobaa had very powerful thunderstorms near the center of the newly formed storm reaching heights above 17 km (10.5 miles). These tall thunderstorms near the center of a tropical cyclone can be as sign that intensification will occur in the future. Rob Gutro \| EurekAlert! New research calculates capacity of North American forests to sequester carbon 16.07.2018 \| University of California - Santa Cruz Scientists discover Earth's youngest banded iron formation in western China 12.07.2018 \| University of Alberta For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 17.07.2018 \| Information Technology 17.07.2018 \| Materials Sciences 17.07.2018 \| Power and Electrical Engineering	<urn:uuid:812a80a5-f900-43b8-86ed-71758cd49e81>	2.984375	1,192	Content Listing	Science & Tech.	52.003562	95,578,172
For the first time ever, researchers at TU Graz and the Medical University of Graz have managed to functionally characterise the three-dimensional interaction between red-light receptors and enzymatic effectors. The results, with implications for optogenetics, have been published in Science Advances. The aim of optogenetics is to control genetically modified cells using light. A team of Graz scientists led by Andreas Winkler from the Institute of Biochemistry at TU Graz have set a milestone in the future development of novel red-light regulated optogenetic tools for targeted cell stimulation. For the first time ever, they were able to observe molecular principles of sensor-effector coupling in the full-length structure of a red-light responsive protein and describe detailed mechanisms of signal transmission over long distances at a molecular level. The results of the research have been published in the open access journal Science Advances. Helix as light switch To survive, cells and organisms have to adapt to new environmental conditions. This is the job of “protein building blocks” which interact with each other in different ways, thus creating cellular networks which allow adaptations to be made to changed environments. The sensors or “receptors” of external stimulation, such as light, are at least in part coupled to specific effectors in order to specifically activate or inhibit cellular signal molecules depending on need. The Graz research group, which comprises not only researchers from TU Graz but also scientists from the Medical University of Graz, presents molecular details of a red-light photo-receptor, involved in the production of a central bacterial messenger molecule, and describes the structure of a full-length light-receptor together with its enzymatic effector for the first time. The architecture and composition of the linker element connecting the sensor and effector is very important in light regulation. TU Graz biochemist Andreas Winkler, head of the research group: “By using a combination of x-ray structural analysis and hydrogen-deuterium exchange, by which the structural dynamics and conformational changes can be analysed, we managed to better understand the functional characteristics of this helical coupling element. We were able to show that illuminating the sensor with red light resulted in a rotation-like change in the coiled coil linker region, which in turn effects the enzymatic activity of the neighbouring effector.” The Graz researchers were thus able to determine structural details of a red-light regulated full-length system and describe molecular mechanisms of signal transduction. Towards a rational design of proteins The research contributes to better understanding the modularity of naturally occurring protein domains and being able to develop new optogenetic tools. Diverse combinations of different sensor modules are found in nature, such as red-light sensors, blue-light sensors and pH sensors – sometimes with identical and sometimes different effectors. From this, the researchers conclude that there are molecular similarities in signal transduction and therefore that rational and completely arbitrary combinations of sensors and effectors which do not occur in nature are conceivable. Andreas Winkler: “We are currently limited to naturally occurring systems to a great extent in the use of directly regulated enzymatic functionalities. The long-term aim is to generate new light-regulated systems which can overcome the limitations of nature and which would be of great interest for different applications in optogenetics.” This project is anchored in the Field of Expertise “Human & Biotechnology”, one of five research foci of TU Graz. The researchers involved are also members of BioTechMed-Graz, a joint project of TU Graz, the Medical University of Graz and the University of Graz. Ass Prof. Dipl.-Ing. Dr.techn. Institut of Biochemistra Graz Universtiy of Technology Tel.: +43 316 873 6457 Barbara Gigler \| Technische Universität Graz Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides 16.07.2018 \| Tokyo Institute of Technology The secret sulfate code that lets the bad Tau in 16.07.2018 \| American Society for Biochemistry and Molecular Biology For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 16.07.2018 \| Physics and Astronomy 16.07.2018 \| Life Sciences 16.07.2018 \| Earth Sciences	<urn:uuid:d52e91a6-ea54-4394-ac1f-144a745578b1>	2.59375	1,471	Content Listing	Science & Tech.	31.498896	95,578,173
Nasa's Mars Odyssey orbiter is set to listen for possible radio transmissions from the Phoenix Mars lander, to check if it has survived the Martian winter. The agency said that communication from the lander was "extremely unlikely". Phoenix's last communication was on 2 November 2008, after it completed its study of an arctic Martian site. Since then, this landing site has gone through autumn, winter and part of spring, and Phoenix was not designed to survive such temperature extremes. Its electronics are likely to have broken up as temperatures plummeted. But, just in case, Odyssey will pass over the Phoenix landing site approximately 10 times each day during three consecutive days of listening, beginning on 18 January. It will undertake two longer "listening campaigns" in February and March. The solar-powered Phoenix landed in May 2008, in the middle of the Martian summer, when the Sun never set at its polar landing site. During its ground operations, the robot dug up and tested the Martian soil to see whether it had ever been capable of supporting life. Probably its biggest achievement was in becoming the first Mars mission to "touch water" in the form of the ice it found just below the topsoil. BBC News has contributed to the report. Russia has left the list of 33 largest holders of US government bonds, after the country disposed of at least a third of remaining bonds	<urn:uuid:b623d425-d2af-407a-a2db-d411cea70171>	3.15625	284	News Article	Science & Tech.	45.751174	95,578,198
Imagine yourself standing outside a country home on an early spring morning just before dawn. Take a deep breath and shiver to the taste of the sweet morning air. Listen carefully to hear the chirping of morning birds. As the sun reaches the horizon, glinting shafts of light reach your eyes. Another deep breath and you feel a peace that comes from a resonance between you and the world at your doorstep. Your eyes close and for a fleeting moment you understand the universe in its simplest most basic terms. Savor that moment, for your eyes open again and now you are drawn back to the reality—you are reading the introduction to a book on physical chemistry. If you are mildly perturbed at being returned to this apparently less appealing reality, you have just demonstrated a facility with a key and exquisitely valuable tool in the study of science, the Gedanken experiment (thought experiment). The use of thought trips will be of fundamental importance in the approach that this book takes toward understanding biophysical processes. That virtually any student has access to one of the most profound and sophisticated theoretical techniques available to a scientist is an important lesson to learn. This is just one of the lessons that this short experiment or mind trip has pointed out to us already. Are there other lessons? KeywordsThought Experiment Deep Breath Physical Universe Biophysical Chemistry Gedanken Experiment Unable to display preview. Download preview PDF.	<urn:uuid:51447d71-68dc-447b-990e-3cbd5ac4e4a2>	3.265625	287	Truncated	Science & Tech.	43.343426	95,578,202
Although an atom’s electrons participate directly in chemical reactions, the nucleus also plays a role; in essence, the protons “set the stage” for the atom, determining its properties as an element and creating positive electrical forces balanced by the negative electrons. Chemical reactions are electrical in nature; both positive and negative particles in an atom dictate how it forms molecules with other atoms. Chemistry involves the electrons more than the nucleus; atoms gain, lose and share electrons with other atoms, forming molecules. For those elements with many electrons, only the outermost ones take part in chemical reactions; those closer to the nucleus are bound to the atom more tightly and are less able to move to other atoms. Although the nucleus affects an atom’s chemical properties, chemical reactions do not change the nucleus in any way. In The Nucleus The nucleus of an atom is made up of protons and neutrons; protons have a positive electric charge whereas neutrons have none. Protons and neutrons have similar mass, with each having about 2,000 times the mass of an electron. The particles are held together by an attraction called the strong force, which is stronger than the electric repulsion that would otherwise cause the positively-charged protons to fly apart from each other. Protons, Neutrons and Chemistry In the nucleus, protons exert a positive electrical charge, attracting the negative charge of electrons and repelling the positive charges of the nuclei of nearby atoms. The tug-of-war between positive and negative forces is important in many aspects of chemistry, including the determination of melting and boiling points, the solubility of one substance by another, and the shapes of molecules. On the other hand, neutrons, having no charge, act as “silent partners” that do not affect chemical properties. In a neutral atom, the number of protons and electrons are equal; the electric charges balance, giving the atom a net charge of zero. An ion, however, has either too few or too many electrons, shifting the balance positive or negative. A positive ion, for example, is missing one or more electrons; neighboring atoms “feel” the positive electric charge from the protons in its nucleus. Negative and positive ions attract each other strongly, forming ionic solids such as sodium chloride salt.	<urn:uuid:748c7104-db5d-49da-8758-92ceffbc20c6>	4.5	480	Knowledge Article	Science & Tech.	24.712816	95,578,211
In a presentation at this year's meeting of the American Association for the Advancement of Science, Michigan State University systems ecologist and modeler Laura Schmitt-Olabisi shows how system dynamics models effectively communicate the challenges and implications of climate change. "In order to face the ongoing challenges posed by climate adaptation, there is a need for tools that can foster dialogue across traditional boundaries, such as those between scientists, the general public and decision makers," Schmitt-Olabisi said. "Using boundary objects, such as maps, diagrams and models, all groups involved can use these objects to have a discussion to create possible solutions." Schmitt-Olabisi has vast experience working directly with stakeholders using participatory model-building techniques. She uses a model of a hypothetical heat wave in Detroit to illustrate the implications of climate change. Climate change is anticipated to increase the frequency and intensity of heat waves in the Midwest, which could potentially claim hundreds or thousands of lives. Hot weather kills more people in the United States annually than any other type of natural disaster, and the impacts of heat on human health will be a major climate change adaptation challenge. To better understand urban health systems and how they respond to heat waves, Schmitt-Olabisi's team interviewed urban planners, health officials and emergency managers. They translated those interviews into a computer model along with data from earlier Midwestern heat waves. Participants are able to manipulate the model and watch how their changes affect the outcome of an emergency. The exercise revealed some important limitations of previous approaches to reducing deaths and hospitalizations caused by extreme heat. "The model challenges some widely held assumptions, such as the belief that opening more cooling centers is the best solution," Schmitt-Olabisi said. "As it turns out, these centers are useless if people don't know they should go to them." More importantly, the model provides a tool, a language that everyone can understand. It is a positive example of how system dynamics models may be used as boundary objects to adapt to climate change, she added. Overall, Schmitt-Olabisi finds that this approach is a powerful tool for illuminating problem areas and for identifying the best ways to help vulnerable populations. Future research will focus on improving the models' accuracy as well as expanding it beyond the Midwest. "In order for the models to be deployed to improve decision-making, more work will need be done to ensure the model results are realistic," Schmitt-Olabisi said. Layne Cameron \| EurekAlert! Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany 25.06.2018 \| Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF Dry landscapes can increase disease transmission 20.06.2018 \| Forschungsverbund Berlin e.V. A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Power and Electrical Engineering 20.07.2018 \| Information Technology 20.07.2018 \| Materials Sciences	<urn:uuid:9979a5a3-870c-43d9-b6e9-b6ed0c1300db>	3.15625	1,114	Content Listing	Science & Tech.	32.349037	95,578,216
Researchers at the University of Southampton have captured unprecedented data about some of the coldest abyssal ocean waters on earth – known as Antarctic Bottom Water (AABW) – during first voyage of the yellow robotic submersible known as Boaty McBoatface. Footage captured by aerial drones as part of a narwhal research camp in Tremblay Sound, Nunavut, Canada is giving biologists new insights into the behaviour of one of the world's most mysterious whales, the long tusked Narwhal. In the footage, a narwhal can be seen using quick taps of its tusk to stun Arctic cod, rendering them immobile and thus easier to capture and eat. Recyclers Viridor have teamed up with packaging specialist Nextek to find a way to sort the supermarket food tray waste mountain. Leak detectives are using Victorian 'sticks' to save 900 million litres of water hidden but leaking under the streets of north-west England. The Natural History Museum (NHM) has successfully achieved £11 million in energy savings and reduced carbon emissions by over 15,000 tonnes during the past decade thanks to a trigeneration scheme in partnership with Vital Energi.	<urn:uuid:6bd4f7c1-a04e-4cdc-9356-976f222b545a>	2.703125	246	Content Listing	Science & Tech.	28.577899	95,578,234
Modeling Leatherback Sea Turtle Populations: How Can Counting Be So Difficult? New York City College of Technology April 30, 2012 Bailey Hall 207 Refreshments will be served in Bailey Hall 204 at 4:30 After at least 60 million years in the world's oceans, human activities have causes leatherback sea turtles to become critically endangered. The largest of all sea turtles with carapace lengths of over six feet in adults, the natural lifespan of a leatherback is over one hundred years. Though they spend their adult lives migrating back and forth across the ocean, sea turtles are born on land. Their migratory patterns mean that leatherback sea turtles live not in one environment but in many environments that are linked together. This has significant ramification for understanding population dynamics and for management and protection of the species. Coupled cell networks are linked systems of differential equations. In this talk we give an introduction to ecological modeling and to coupled cell networks as they relate to modeling leatherback sea turtle population dynamics. \|Union College Math Department Home Page\| Comments to: firstname.lastname@example.org Created automatically on: Mon Jul 23 03:38:51 EDT 2018	<urn:uuid:a84cd4b5-4cac-4e52-b9ea-17d089c867ff>	2.953125	243	News (Org.)	Science & Tech.	37.799423	95,578,238
Researchers have provided new insights into how a species of air-breathing spider can spend its whole life under water, only venturing to the surface occasionally to replenish its air supply. The "diving bell spider" (Argyroneta aquatica) is the only spider that lives entirely under water. It breathes air, which it traps in a dome-shaped web suspended between aquatic plants. It's this bubble that gives the spider its name – and we now know how it works. The scientists found that the "diving bell" behaves like a gill, extracting oxygen from the water. The spider needs to dash to the surface only once a day to supplement its air supply, and it can stay under water for more than 24 hours. Says Professor Roger Seymour of the University of Adelaide: "Being able to stay still for so long, without having to go to the surface to renew the air bubble, protects the spiders from predators and also keeps them hidden from potential prey that come near." - Source: University of Adelaide	<urn:uuid:2bb52139-f721-4caf-8484-c4b15afafafc>	3.46875	211	News Article	Science & Tech.	43.513684	95,578,239
reluctance(redirected from reluctances) Also found in: Dictionary, Thesaurus, Legal. reluctance(less commonly), reluctancy A property of a magnetic circuit analogous to resistance in an electric circuit. Every line of magnetic flux is a closed path. Whenever the flux is largely confined to a well-defined closed path, there is a magnetic circuit. That part of the flux that departs from the path is called flux leakage. For any closed path of length l in a magnetic field H, the line integral of H cos α dl around the path is the magnetomotive force (mmf) of the path, as in Consider the closely wound toroid shown in the illustration. For this arrangement of currents, the magnetic field is almost entirely within the toroidal coil, and there the flux density or magnetic induction B is given by a characteristic of a magnetic circuit; the reluctance R m is equal to the ratio of the magnetomotive force F acting on a magnetic circuit to the magnetic flux Φ developed in the circuit. For a uniform section of a magnetic circuit the reluctance can be calculated from the formula Rm = l/μμ0S, where l and S are the length and cross section of the section of the magnetic circuit, respectively; μ is the relative magnetic permeability of the material in the circuit; and μ0 is the magnetic constant. In the case of a nonuniform magnetic circuit composed of successive uniform sections having different values of l, S, and μ, the reluctance is equal to the sum of the values of Rm for the uniform sections. Such a computation is approximate, since the formula does not take into account “magnetic leakage” (the diffusion of magnetic flux into the space surrounding the magnetic circuit), the nonuniformity of the magnetic field in the circuit, and the nonlinear dependence of the reluctance on the field. In a variable magnetic field the reluctance is a complex quantity, because in this case μ, is a function of the frequency of the electromagnetic oscillations. The unit of reluctance in the International System of Units is the ampere or ampere-turn per weber (A/Wb), and in the cgs system of units, the gilbert per maxwell (Gb/Mx); 1 A/Wb = 4 × 10-9 Gb/Mx ≈ 1.2566 × 10-8 Gb/Mx.	<urn:uuid:7cbc7fa1-bda8-4c15-94fd-5a556d7ae5ee>	3.1875	509	Structured Data	Science & Tech.	37.86407	95,578,268
Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore. Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly visualized the nuclear pore’s selective barrier, but also its dynamic behavior to resolve a long-standing mystery of how unwanted molecules are prevented from entering the nucleus. Nuclear pore complexes regulate the transport of molecules The overall structure of the nuclear pores is generally known. These are not simple holes, but are massive transport hubs that incorporate by the thousands into the nuclear membrane. They have a donut-shaped structure consisting of about thirty different proteins, called nucleoporins, and a central transport channel. Within the pore, several disordered proteins (FG Nups) form a selectivity barrier or filter. While small molecules can easily pass this barrier, large molecules such as proteins are prevented from entering the nuclear pore. An exception to this are the proteins needed in the cell nucleus, for example, for the repair or replication of genetic material. Their translocation from the cytoplasm to the nucleus is assisted by transport receptors that recognize a specific “address tag” carried by these proteins. High-speed AFM reveals dynamic processes “With the high-speed AFM we could for the first time, peer inside native nuclear pore complexes, only forty nanometers in size”, says Lim. “This method is a real game changer. We could see the individual FG Nups and film them in action. This wasn’t possible until now!” Additionally, Yusuke Sakiyama, the PhD student who performed the experiments, had to grow super-sharp carbon nanofibers on each high-speed probe in order to reach inside the NPC. This then generates a video sequence from multiple images that enables the researcher to observe the “true to life” dynamics of biological processes at the nanometer level. A barrier of undulating molecular “tentacles” Due to the high spatial and temporal resolution, the scientists were able to show that the FG Nup filaments are highly flexible. “They are not stiff bristles but quite the contrary. Like the thinnest tentacles, the FG Nups rapidly fluctuate, elongate and retract, and sometimes even briefly intermingle within the pore”, says Lim. The speed of their motion determines which molecules can pass through the pore. “Large particles move much more slowly than the FG Nups and are thus hindered from entering the NPC by repeated collisions”, explains Lim. “Small molecules, however, undergo rapid diffusion and have a high probability of passing the FG Nup barrier.” By understanding how NPCs function as transport hubs in living cells, Lim who is a member of the NCCR Molecular Systems Engineering is now investigating how NPC-inspired selective filters might regulate molecular traffic in non-biological systems. Yusuke Sakiyama, Adam Mazur, Larisa E. Kapinos and Roderick Y.H. Lim Spatiotemporal dynamics of the nuclear pore complex transport barrier resolved by high-speed atomic force microscopy Nature Nanotechnology (2016), doi: 10.1038/nnano.2016.62 Prof. Dr. Roderick Lim, University of Basel, Biozentrum, and Swiss Nanoscience Institute, phone: +41 61 267 20 83, E-Mail: firstname.lastname@example.org Dr. Katrin Bühler, University of Basel, Biozentrum, Communications, tel. +41 61 267 09 74, email: email@example.com http://www.biozentrum.unibas.ch/research/groups-platforms/overview/unit/lim/ - Research group Prof. Roderick Lim http://dx.doi.org/10.1038/nnano.2016.62 - Abstract Dr. Katrin Bühler \| Universität Basel World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes 17.07.2018 \| Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt Plant mothers talk to their embryos via the hormone auxin 17.07.2018 \| Institute of Science and Technology Austria For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 17.07.2018 \| Life Sciences 17.07.2018 \| Information Technology 17.07.2018 \| Power and Electrical Engineering	<urn:uuid:77cb0faa-31ec-4217-8c08-9bd96ceea71a>	2.8125	1,608	Content Listing	Science & Tech.	40.322784	95,578,273
Although most of us know that whales and dolphins are highly intelligent mammals, with brain sizes comparable to those of humans, scientists and researchers are continually discovering how these animals are perfectly adapted to their marine environment, and rely on certain senses to successfully hunt and navigate in the wild. Toothed whales, also known as Odontocetes, that use echolocation are primarily dolphins, porpoises, river dolphins, orcas and sperm whales. These animals emit calls or 'clicks' into their environment and analyze the echoes that return from various objects around them. From the differences in the echoes, they are able to distinguish relative distance, size, and type of object, seemingly studying it in detail without ever laying eyes on it. In a recent study conducted on a captive toothed whale in Hawaii, researchers found that the whale could focus a sound beam and adjust it to accurately identify two objects with only a hairline fracture difference in width. In observing the whale respond to similar objects placed in her environment, scientists found the whale would intensify the level of echolocation beam to formulate a specific image of the objects, thus getting a larger proportion of energy back from the objects when the beam of sound increased, and creating a clearer image her target. Toothed whales literally map the world around them using sound, and this extraordinary ability enables them to follow and track prey by only using their sense of hearing. These animals have had to adapt to environments with little light (e.g. many whales hunt in deep waters where little or no light permeates) or poor visibility (e.g. river dolphins hunt in muddy waters using sound to locate prey). The accuracy in using echolocation is a must for animals that rely on this technique to capture prey. Some species, such as the Narwhal, also use echolocation to navigate Arctic waters and locate breathing holes in the ice. These mammals must rely on the accuracy of these echoes to find where and when their next breath will be. Researchers have also found that toothed whales are able to heighten the sensitivity of their hearing when required, but also block out loud damaging sounds when present. When Odontocetes species emit 'clicks', these sounds travel through a fatty structure at the front of their skull called the Melon. The latter, distinguishable from the bulbous shape of the animal's head, acts as an acoustic lens, focusing the clicks into sound beams of adjustable size. This incredible feature is what makes toothed whales perfectly adapted to their watery world, and equipped to picture the world around them before they ever see it. Citation: Victoria Gill. "How whales and dophins focus sound beams on prey", BBC Science & Environment. 22.03.12. Wikipedia online encyclopedia. "Animal Echolocation" http://en.wikipedia.org/wiki/Animal_echolocation Even if you have never heard of sustainable development, this term is crucial to our modern world, and even more relevant when considering the existing pressures humans inflict upon our natural resources. For millions of years, the evolution of man has been a mix of adaptation, exploitation, and developing at faster rates as the centuries rolled on. Our history has been shaped by the discovery of the health benefits and economical profits central industries as agriculture, forestry and fisheries provide. Sustainable development is needed more than ever to ensure the management and conservation of our natural and finite resources. Our planet is now carrying 7 billion inhabitants. This is an incredible amount of people and an even more astounding number when we think that most humans depend on agriculture for food (e.g. cattle, chicken, grains, vegetables, etc.), fisheries for protein (e.g. fish, shellfish, mammals, etc) and forests for wood (e.g. building materials, paper, etc.). Sustainable development is key to safeguarding the resources we rely on to live, and protecting the economies and trade relations that depend on resource yield and profit. Global fisheries are an industry that extracts over 100 million tons of fish from our oceans annually. Agriculture is the predominant industry causing the deforestation of the planet's most ancient rainforests and wildlife habitats. Humans must understand and respect that our global environment sustains life on earth, but our natural resources are not endless reservoirs and they can be destroyed if not safeguarded. Humans have already contributed to the extinction of multiple marine and terrestrial creatures, through our insatiable desire for meat, valuable body parts, pelts, etc.). Although individuals, governments and industries are not about to halt the exploitation of the resources our global community relies on, we must limit what we take from the environment, for its sake and our own. Humans have fished nearly all the large species of fish beyond sustainable limits, and this threatens the future needs of our growing world population. If the oceans are fished out, how will we feed the 3.5 billion people who depend on seafood as their primary source of protein? Understanding sustainable development and incorporating ethical principles in our everyday life plays a role in how we shape the consumption, use and demand of our natural resources. Action and participation are needed on every level, whether from citizens or large corporations, all must be involved in developing our world while considering factors such as the environmental health and food security. Prominent industries such as agriculture, fisheries and forestry have been growing over time, and are now shaping the basic cycles, patterns and temperatures of our world climate. Global Warming is a phenomena of environmental change thought to be caused by a multitude of factors relating to industrial pollution, waste, and increasing carbon emissions altering our atmosphere and oceans. The chemistry of our planet is changing, and with that we are witness to extreme environmental degradation, reckless exploitation, and poorly designed trade policies. Our oceans are suffering increased acidification while deforestation is reducing the oxygen-purifying gift our forests provide. The insatiable demand for meat and livestock has destroyed vast expanses of native land while the waste of farmed animals is a great contributor of greenhouse gas emissions polluting our atmosphere every single day. Restoring our global environment, both on land and at sea, is crucial if we are to secure continued life on earth. Although our oceans have provided seemingly endless supplies of seafood for millions of years, humans are aggressively fishing, and like other primary industries, we are exploiting natural resources to dangerous limits. We can each shape our lifestyle to respect the environment the best we can. Our voices can be heard, and if we become engaged in preserving our natural world, we will secure a better future for our planet and its inhabitants. Agriculture and Agri-Food Canada: http://www4.agr.gc.ca/AAFC-AAC/display-afficher.do?id=1175526032952&lang=eng International Institute for Sustainable Development: http://www.iisd.org/ecp/es/Citation: "Environment and Human Security". International Institute for Sustainable Development. http://www.iisd.org/ecp/es/ With the 2003 release of 'Finding Nemo', many of the ocean's hidden treasures came to life, and the enchanting characters of the film, from Nemo the Clownfish to Bruce the shark, brought marine wildlife into our homes and hearts. Beneath the waves lies an aquatic world with magical webs of life, with creatures too small to see and others too large to fathom. However, like in 'Finding Nemo', the underwater world must contend with a growing human presence above and beneath the waves. Although Nemo was poached from the sea by a man looking to fill his aquarium, there are other threats to marine life such as over-fishing, pollution and habitat degradation. According to the International Union for the Conservation of Nature (IUCN), 1 in 6 species from 'Finding Nemo' is vulnerable to extinction. Although hard to imagine the wonderful characters from the film loosing their habitat or being fished out of the sea, this is the reality for many of the real creatures found in our oceans. Marine turtles like 'Squirt' and 'Crush' and 1/2 of all Hammerhead sharks like 'Anchor' are endangered with extinction. Each year, thousands of marine turtles are still hunted in parts of the world, especially in areas where it is tradition to consume turtle meat. Destructive fishing methods such as long-lining and drift-nets claim the lives of innocent turtles every year when the animals get caught in fishing gear. 'Bruce' and 'Chum' tried hard to curb their fishy diets in 'Finding Nemo', but unfortunately they would be facing far more serious challenges if they swam in our seas. Today, over 73 million sharks are killed each year, and these global hunts are taking place in large part due to a high demand for 'shark fin soup'. For thousands of years, Chinese culture has regarded the shark's fin as a sign of affluence or 'high class', and therefore the tradition of the soup evolved by serving the dish at important functions like banquets and weddings. Today, Asian cultures still identify with the soup, which creates a huge demand for the fins, and is therefore contributing to a huge decline in most shark species on our planet. Remember 'Mr.Ray'? He was the wise Eagle ray who taught Nemo and his friends at school, and although there are a multitude of different species of rays roaming our oceans, the Eagle ray is today threatened along with the majestic Manta ray. Sometimes we need to be reminded of the things that we cherish (like beautiful ocean wildlife!), and shown that we can always learn from the world around us. Especially when is comes to our living environment. "Human beings are the stewards of the earth and we are responsible for protecting the species that share our environment" -Simon Stewart, chair of IUCN Species Survival Commission. All cartoon images © of Disney & Pixar's 2003 Finding Nemo. The whales that call our oceans home today are very different from the early mammals that are part of their ancestry. Ancestry: This term refers to individual species which share a genetic (biological) relationship, a common decent with older primitive animals known to have lived on earth. According to various studies and archeological findings, early records of whales have been found in fossils discovered in certain areas of Egypt, Pakistan, and the U.S. (United States). Fossils: These are remains or traces of animals preserved over time. Leaving an indent or bone specimen embedded in rock, findings called "fossils" are usually a minimum of 10,000 years old! The Basilosaurus and the Ambulocetus are two species thought to have lived millions of years ago, and have specific attributes and characteristics leading researchers to confirm they were part of the great whale ancestry. Basilosaurus: First believed to have been reptilian sea monsters or ancient lizards, Basilosaurus fossils were originally found in America (U.S.) and later suggests that they were in fact the "Giant whales" of their time. Possessing mammalian sets of teeth, fossils also showed the presence of short legs tracing early whales back to a terrestrial (living on land) past. Ambulocetus: Possibly an early form of 'whale', skeletal remains of Ambulocetus show a set of legs probably used for propulsion and a similar method of hearing as modern whales. With no external ears, these species are likely to have felt vibrations through their jawbone. Called the "walking whale", Amulocetus looked like a furry Crocodile, but was actually on its way to becoming the biggest ocean mammals on earth! Here are two videos created by the BBC to re-create what the behaviour and appearance of these ancient species would have been like: Evolution-Giant Whales-BBC Science Primitive Whale-BBC Science Across our world oceans, shark populations are being threatened by destructive human activities such as Shark Finning. For more information on this topic, please link to our blog from February 22nd, 2011: http://www.eco-odyssey.com/blog/3/Saving-our-Sharks.html Shark Trust is a great organization committed to helping the sharks of our world survive by making sure humans know and understand how important they are to our ocean ecosystems. They have a fantastic Educational resource page on their website, and its packed with tools, games, and information about sharks. There are ways for all of us to get involved in helping our oceans, big and small, we can all do something! This link is also very useful to teachers, who can download the Marine Educators Teaching Toolkit as incorporate ocean education in schools. So Kids, suggest it to your parents and teachers, and have fun learning about the world's fascinating sharks! "Sea Choice: Healthy choices, healthy oceans" is a Canadian Sustainable Seafood Program working with other organizations to develop, educate and promote healthy oceans by providing solutions and ways we can all play a role in this cause. Kids are especially lucky because Sea Choice is proud to add an "Educator's Guide" that teachers and parents can use to bring ocean education right into the classroom and into your home. This guide provides tools and tips so that children of all ages can participate in becoming active ambassadors in supporting our living oceans. Ask you parents to download this guide or suggest it to your teacher at school so that you and your friends can begin to make a difference for our ocean friends!! Compiled by: George H Burgess and Cathleen Bester BOOKS!!!-Recommended reading material from the Florida Museum of Natural History. Click here to link to the list of wonderful books carrying you into the underwater world of sharks... Reading opens our minds to all types of wonders, and learning about our ocean environment will hopefully motivate you to help protect it now and in the future! In the US alone, 100 million discarded plastic bags end up in the environment. They block drains and other waterways, entangle sea birds, choke marine animals and, as they disintegrate in the ocean, work their way into the food chain. Recycle any supermarket bags you may have	<urn:uuid:6005d166-6197-4291-902c-62095be763a2>	4.28125	2,923	Knowledge Article	Science & Tech.	40.338576	95,578,282
Molten rocks powering your electronics?Geothermal energy constantly gets overshadowed by other sources of clean energy, like wind and solar, because it's still more expensive. But with every passing year, as more resources are invested in developing the technology, geothermal gets closer to its day in the spotlight. It's not hard to imagine a green future where it plays a big role, providing part of the "always on" baseload power to run our civilization. One recent breakthrough in the field took place in Iceland. A borehold drilled in Krafla, in northeast Iceland, surprised engineers by penetrating magma (molten rock), something that had only happened once before, in Hawaii. Depth was 2100 meters and temperature was around 900-1000 Celsius. This provided a great opportunity to test the first ever magma-enhanced geothermal system! The hole generated superheated steam for the next two years (which can be seen on the photo above), but it was then closed down in order to replace some of the surface equipment. “In the future, the success of this drilling and research project could lead to a revolution in the energy efficiency of high-temperature geothermal areas worldwide,” said Wilfred Elders, a professor emeritus of geology at the University of California. “Essentially, the IDDP-1 created the world’s first magma-enhanced geothermal system. This unique engineered geothermal system is the world’s first to supply heat directly from a molten magma.” Several important things were learned with this project: important milestones were achieved in this project: despite some difficulties, the project was able to drill down into the molten magma and control it; it was possible to set steel casing in the bottom of the hole; allowing the hole to blow superheated, high-pressure steam for months at temperatures exceeding 450 C, created a world record for geothermal heat (this well was the hottest in the world and one of the most powerful); steam from the IDDP-1 well could be fed directly into the existing power plant at Krafla; and the IDDP-1 demonstrated that a high-enthalpy geothermal system could be successfully utilized. (source) While most geothermal energy resources don't have magma anywhere near the surface, they still offer potentially vast quantities of clean energy. The National Renewable Energy Lab (NREL) has created the following maps to show geothermal potential in the U.S.: More details on those maps and bigger pictures can be found here.	<urn:uuid:b3237a4b-4929-4cd4-8a7c-c7bb573a2c68>	3.59375	528	Knowledge Article	Science & Tech.	35.065348	95,578,290
It’s not every day you get to see a star go nova. Scientists at Warsaw University Observatory in Poland have managed to catch a binary star system both before and after its explosive flash. The findings, described in the journal Nature, confirm a long-held theory about novae known as the hibernation hypothesis – and could potentially help scientists better understand when such stellar outbursts occur. Novae are typically caused by a gravitationally locked pair of stars, called a binary system, consisting of one white dwarf and a companion star. A white dwarf is an aging star that has already shed much of its mass, leaving behind a small but massive core. Like a gravitational vampire, the white dwarf siphons off material from its stellar companion – and every so often, the system becomes so unstable that the white dwarf erupts, producing a cataclysmic explosion that causes it to flare brightly in the night sky. “The most spectacular eruptions, with a ten-thousandfold increase in brightness, occur in classical novae and are caused by a thermonuclear runaway on the surface of the white dwarf,” the study authors wrote. “Such eruptions are thought to recur on time scales of ten thousand to a million years.” Such explosions might actually have seeded the universe with some elements and radioactive isotopes, such as lithium, said lead author Przemek Mroz, an astronomer at the observatory. About 50 novae go off every year in the Milky Way, but only five to 10 are actually observed because most of them are shrouded by interstellar gas and dust, Mroz said in an email. The closest and brightest, however, can potentially be picked out with the naked eye. But though novae can be seen once they go off, scientists don’t often get the chance to study them in depth before they explode. Researchers have long had a theory about the cycle that causes these novae: When the mass transfer is low, the accretion grows unstable; every so often, the white dwarf experiences what the authors called “dwarf nova outbursts.” Dwarf nova outbursts occur when material from the accretion disk is dumped onto the star’s surface, Mroz said; the dramatic classical nova event occurs on the surface of the white dwarf when there is enough gas to ignite thermonuclear reactions. “This is the first time [that] we observed a dwarf nova that transformed into a classical nova,” Mroz said of his team’s findings. When the classical nova explosion finally occurs, it actually boosts the mass-transfer rate for centuries, keeping the system more stable until it dwindles and begins to approach the “hibernation” period, thus repeating the process. But scientists couldn’t say what was really happening until the nova V1213 Cen flashed in 2009 and was caught by the university’s Optical Gravitational Lensing Experiment. “This discovery would be impossible without long-term observations by the OGLE survey,” Mroz wrote in an email. “The survey started almost 25 years ago and for 20 years we have had a dedicated 1.3-meter telescope at Las Campanas Observatory in Chile. This is another case when OGLE data are crucial for studying unique, extremely rare phenomena.” Please like, share and tweet this article. Pass it on: New Scientist	<urn:uuid:96178e32-8f85-42f5-ae40-7caf2f997796>	3.96875	731	News Article	Science & Tech.	38.414697	95,578,291
Researchers at the Helmholtz Centre for Environmental Research (UFZ) have processed existing data on global UV-B radiation in such a way that scientists can use them to find answers to many ecological questions. According to the paper published in Methods in Ecology and Evolution, an online journal of the British Ecological Society, this data set allows drawing new conclusions about the global distribution of animal and plant species. Many research projects study the effects of temperature and precipitation on the global distribution of plant and animal species. However, an important component of climate research, the UV-B radiation, is often neglected. The landscape ecologists from UFZ in collaboration with their colleagues from the Universities in Olomouc (Czechia), Halle and Lüneburg have processed UV-B data from the U.S. NASA space agency in such a way that they can be used to study the influence of UV-B radiation on organisms. UV-B Durchschnittswerte mit der im Schnitt höchsten monatlichen Strahlungsintensität weltweit. (Quelle: Tomáš Václavík/UFZ) UV-B Durchschnittswerte mit der im Schnitt niedrigsten monatlichen Strahlungsintensität weltweit. (Quelle: Tomáš Václavík/UFZ) The basic input data were provided by a NASA satellite that regularly, since 2004, orbits the Earth at an altitude of 705 kilometres and takes daily measurements of the UV-B radiation. "For us, however, not daily but the long-term radiation values are crucial, as these are relevant for organisms", says the UFZ researcher Michael Beckmann, the lead author of the study. The researchers therefore derived six variables from the UV-B radiation data. These include annual average, seasonality, as well as months and quarters with the highest or lowest radiation intensity. In order to process the enormous NASA data set, the UFZ researchers developed a computational algorithm, which not only removed missing or incorrect readings, but also summed up the daily measurements on a monthly basis and determined long-term averages. The processed data are currently available for the years 2004-2013 and will be updated annually. With this data set, scientists can now perform macro-ecological analyses on the effects of UV-B radiation on the global distribution of animal and plant species. "While there are still many uncertainties", says Michael Beckmann, "the UV radiation is another factor that may explain why species are present or absent at specific sites." The data set can also help addressing other research questions. Material scientists can identify strategies to provide better protection to UV-sensitive materials, such as paints or plastics, in specific regions of the world. Human medicine could use the data set to better explain the regional prevalence of skin diseases. "There are no set limits as to how researchers can use these data", says Beckmann. The data are now freely available for download on the internet and visually presented in the form of maps. These maps show, for example, that in countries in the southern hemisphere, such as New Zealand, the UV-B radiation is up to 50 percent higher than in the countries in the northern hemisphere, such as Germany. In general, the UV irradiation in winter is lower than in summer due to a shorter daily sunshine duration. Background: Unlike the rather harmless UV-A radiation, the high-energy UV-B radiation causes health problems to humans, animals and plants. Well known is the higher risk of skin cancer in the New Zealand and Australia population if unprotected and exposed to sun for an extended period of time. Skin damage was also documented in whales and amphibians. In amphibians, UV-B radiation may also reduce survival rates of tadpoles and spawn eggs. In plants, the radiation reduces performance of photosynthesis, a process of using solar energy to convert carbon dioxide and water into sugars and oxygen. This inhibits production of biomass and thus reduces e.g. yields of agricultural crops. Beckmann, M., Václavík, T., Manceur, A. M., Šprtová, L., von Wehrden, H., Welk, E., Cord, A. F. (2014), glUV: a global UV-B radiation data set for macroecological studies. Methods in Ecology and Evolution. doi: 10.1111/2041-210X.12168 Helmholtz Centre for Environmental Research - UFZ Tilo Arnhold, Susanne Hufe (UFZ-Public Relations) Phone: +49-(0)341-235-1635, -1630 The data set (global UV-B data set for macroecology: glUV) is freely available for download at In the Helmholtz Centre for Environmental Research (UFZ), scientists conduct research into the causes and consequences of far-reaching environmental changes. Their areas of study cover water resources, biodiversity, the consequences of climate change and possible adaptation strategies, environmental technologies and biotechnologies, bio-energy, the effects of chemicals in the environment and the way they influence health, modelling and social-scientific issues. Its guiding principle: Our research contributes to the sustainable use of natural resources and helps to provide long-term protection for these vital assets in the face of global change. The UFZ employs more than 1,100 staff at its sites in Leipzig, Halle and Magdeburg. It is funded by the federal government, Saxony and Saxony-Anhalt. http://www.ufz.de/ The Helmholtz Association contributes to solving major and urgent issues in society, science and industry through scientific excellence in six research areas: Energy, earth and environment, health, key technologies, structure of matter as well as aviation, aerospace and transportation. The Helmholtz Association is the largest scientific organisation in Germany, with 35,000 employees in 18 research centres and an annual budget of around €3.8 billion. Its work is carried out in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894). http://www.helmholtz.de/ Benjamin Haerdle/Susanne Hufe \| UFZ News Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany 25.06.2018 \| Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF Dry landscapes can increase disease transmission 20.06.2018 \| Forschungsverbund Berlin e.V. For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 19.07.2018 \| Materials Sciences 19.07.2018 \| Earth Sciences 19.07.2018 \| Life Sciences	<urn:uuid:ad553020-ac55-4f7a-9fd9-c96ec2369022>	4.125	1,974	Content Listing	Science & Tech.	42.210887	95,578,302
US Coral Reefs in the Line and Phoenix Islands, Central Pacific Ocean: Status, Threats and Significance This is the second of two chapters on the coral reefs of the five US Line and Phoenix Islands, consisting of Baker, Howland and Jarvis Islands, Kingman Reef, ; and Palmyra Atoll (Fig. 16.1). The previous chapter (Chapter 15, Maragos et al.) covers the history, geology, oceanography and biology, while this chapter covers the status, threats and significance of the five. All are low reef islets or atolls in the central Pacific Ocean administered by the US Fish and Wildlife Service as National Wildlife Refuges. These 5 Refuges are among 20 within the tropical Pacific and among 10 that protect coral reefs. Together they are geographically a part of the largest series of fully protected marine areas under unified management in the world. KeywordsCoral Reef World Heritage National Wildlife Refuge Reef Shark Central Pacific Ocean Unable to display preview. Download preview PDF.	<urn:uuid:3043d555-5aa7-4800-a4e9-ad32c37b707d>	3.578125	207	Truncated	Science & Tech.	39.26762	95,578,318
The new observations promise to help scientists understand the early stages of a sequence of events through which a giant cloud of gas and dust collapses into dense cores that, in turn, form new stars. New observations show 'pristine' example of second stage of star formation shown in this graphic. (Images not to scale.) CREDIT: Bill Saxton, NRAO/AUI/NSF The scientists studied a giant cloud about 770 light-years from Earth in the constellation Perseus. They used the European Space Agency's Herschel Space Observatory and the National Science Foundation's Green Bank Telescope (GBT) to make detailed observations of a clump, containing nearly 100 times the mass of the Sun, within that cloud. Stars are formed, astronomers think, when such a cloud of gas and dust collapses gravitationally, first into clumps, then into dense cores, each of which can then begin to further collapse and form a young star. The details of how this happens are not well understood. One difficulty is that most regions where this process is underway already have formed stars nearby. Those stars affect subsequent nearby star formation through their stellar winds and shock waves when they explode as supernovae. "We have found the first clear case of a clump of potentially star-forming gas that is on the verge of forming dense cores, and is unaffected by any nearby stars," said James Di Francesco, of the University of Victoria, Canada. "Finding such a 'pristine' clump of gas that may be starting to form dense cores is a key to gaining a fuller understanding of the early stages of star formation," said Sarah Sadavoy, a graduate student also of the University of Victoria. "This is a rare find," she added. The far-infrared images from the Herschel Space Observatory were obtained as part of the Herschel Gould Belt Survey key program. They revealed previously-unseen substructures within the clump that may be precursors to cores with the potential to form individual stars. The astronomers used the GBT to study the motions and temperatures of molecules, primarily ammonia, within these substructures. These GBT observations indicated that one of the substructures is likely to be gravitationally bound and thus farther along the path to condensing into a core than the others. "This may be the first observation ever of a core precursor," DiFrancesco said. The entire clump, the scientists say, could be expected to form about ten new stars. "This region appears to be an excellent candidate for future core formation, and thus is an ideal area for additional studies that can help us understand how this process works without the triggering effect of winds from other stars and shocks from supernova explosions," Sadavoy said. The scientists will publish their results in the journal Astronomy & Astrophysics. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Dave Finley \| EurekAlert! Computer model predicts how fracturing metallic glass releases energy at the atomic level 20.07.2018 \| American Institute of Physics What happens when we heat the atomic lattice of a magnet all of a sudden? 18.07.2018 \| Forschungsverbund Berlin A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Power and Electrical Engineering 20.07.2018 \| Information Technology 20.07.2018 \| Materials Sciences	<urn:uuid:76d35046-0cc7-4eed-bcf2-4fca501fa056>	3.640625	1,194	Content Listing	Science & Tech.	40.157607	95,578,330
Although song is often learnt from an adult model, there is some evidence of active vocal learning among siblings. Researchers from the Max Planck Institute for Ornithology in Seewiesen now showed that juvenile zebra finches that have been raised without their fathers are able to learn their song via a brother. Singing siblings: zebra finches that grew up without their dads and therefore without a "song model", don't have to worry about having no singing repertoire. As researchers discovered, the birds can also learn their song through their brothers. Image: Huet des Aunay When comparing the songs of the two brothers, they turned out to be more alike than the song of the brother with its father. Thus, just like an adult tutor, a juvenile peer has the same potential to serve as a song model.Social learning from peers is a widespread phenomenon in infants. Peer group size may influence the degree to which interactions within the group can influence their own behaviour. This insight nowadays gains more importance as an increasing number of children get into contact with large group peers at an even earlier age, for example in day nurseries. The type of social partners can also be crucial for the intensity of social learning. A well-known example is the spontaneous development of a particular language in adolescent deaf children in several schools in Nicaragua in the eighties. These pupils invented a private sign-language with Creole characteristics. With this, they emancipated themselves from their unaware teachers who taught the normal sign language. Therefore, the same-age peers had the same or an even larger role model function than the adult teachers. First, they found that juveniles exposed to their fathers learned his song, although the degree of song learning showed large individual variation, which the researchers attributed to the relatively short exposure period. These sons were then able to transmit their songs to their brothers that had been without their fathers since they were two weeks old. Remarkably, after the completion of the song learning phase as adults, there was a high similarity in the songs of the two brothers. This similarity was even higher than the similarity that the researchers measured between the paternal song and the song of the son to whom he was exposed.These results show that a juvenile peer can be a role model that is as efficient as an adult suggesting a large social component underlying song learning, explains Sébastien Derégnaucourt. (SL/HR) Biology Letters, June 12, 2013; doi: 10.1098/rsbl.2013.0247 Dr. Sabine Spehn \| Max-Planck-Institut Scientists uncover the role of a protein in production & survival of myelin-forming cells 19.07.2018 \| Advanced Science Research Center, GC/CUNY NYSCF researchers develop novel bioengineering technique for personalized bone grafts 18.07.2018 \| New York Stem Cell Foundation A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Power and Electrical Engineering 20.07.2018 \| Information Technology 20.07.2018 \| Materials Sciences	<urn:uuid:91fe90e6-129e-4a9a-8039-4d7784c29208>	3.875	1,110	Content Listing	Science & Tech.	42.951029	95,578,341
This article is written like a manual or guidebook. (January 2012) (Learn how and when to remove this template message) In Microsoft Windows applications programming, OLE Automation (later renamed to simply Automation) is an inter-process communication mechanism created by Microsoft. It is based on a subset of Component Object Model (COM) that was intended for use by scripting languages - originally Visual Basic - but now is used by several languages on Windows. All automation objects are required to implement the IDispatch interface. It provides an infrastructure whereby applications called automation controllers can access and manipulate (i.e. set properties of or call methods on) shared automation objects that are exported by other applications. It supersedes Dynamic Data Exchange (DDE), an older mechanism for applications to control one another. As with DDE, in OLE Automation the automation controller is the "client" and the application exporting the automation objects is the "server". Contrary to its name, automation objects do not necessarily use Microsoft OLE, although some of Automation objects can be used in OLE environments. The confusion has its roots in Microsoft's earlier definition of OLE, which was previously more or less a synonym of COM. Automation-compatible COM servers can, however, rely on the in-built OLE marshalling implementation. This avoids the need for additional proxy/stub projects for marshalling out-of-process. Automation was designed with the ease of scripting in mind, so controllers often provide languages such as Visual Basic for Applications to end users, allowing them to control automation objects via scripts. Automation objects are often written in conventional languages such as C++, where C++ attributes can be used to simplify development, Languages such as Visual Basic and Borland Delphi also provides a convenient syntax for Automation which hides the complexity of the underlying implementation. In order to automate an application, the developer of an automation controller must know the object model that is employed by the target application exporting activation objects. This requires that the developer of the target application publicly document its object model. Development of automation controllers without knowledge of the target application's object model is "difficult to impossible". Because of these complications, Automation components are usually provided with type libraries, which contain metadata about classes, interfaces and other features exposed by an object library. Interfaces are described in Microsoft Interface Definition Language. Type libraries can be viewed using various tools, such as the Microsoft OLE/COM Object Viewer ( oleview.exe, part of the Microsoft Platform SDK) or the Object Browser in Visual Basic (up to version 6) and Visual Studio .NET. Type libraries are used to generate Proxy pattern/stub code for interoperating between COM and other platforms, such as Microsoft .NET and Java. For instance, the .NET Framework SDK includes tools that can generate a proxy .NET DLL to access Automation objects using both early binding (with information about interfaces extracted from a type library) and late binding (via IDispatch, mapped to the .NET Reflection API), with the built-in .NET-to-COM bridge called COM Interop. While Java lacks built-in COM support, toolsets like JACOB and jSegue can generate proxy source code (consisting of two parts, a set of Java classes and a C++ source for a Java Native Interface DLL) from type libraries. These solutions only work on Windows. Another Java based j-Interop library which enables interoperability with COM components without JNI, using DCOM wire protocol (MSRPC) and works on non-Windows platforms also. Microsoft has publicly documented the object model of all of the applications in Microsoft Office, and some other software developers have also documented the object models of their applications. Object models are presented to automation controllers as type libraries, with their interfaces described in ODL. Automation is available for a variety of languages, including, but not limited to: Manage research, learning and skills at defaultLogic. Create an account using LinkedIn or facebook to manage and organize your Digital Marketing and Technology knowledge. defaultLogic works like a shopping cart for information -- helping you to save, discuss and share.Visit defaultLogic's partner sites below:	<urn:uuid:6db68764-4a7c-40d0-aafc-ecad8c9107f9>	3.171875	870	Knowledge Article	Software Dev.	22.084489	95,578,365
\|Observation data (Epoch J2000)\| \|Right ascension\|\|16h 35m 54s\| \|Declination\|\|+66° 13′ 00″\| \|Number of galaxies\|\|~10,000\| \|Bautz-Morgan classification\|\|II \| 719 Mpc (2,345 Mly) h−1\| \|X-ray flux\|\|(7.50 ± 9.1%)×10−12 erg s−1 cm−2 (0.1—2.4 keV) \| Acting as a powerful lens, it magnifies and distorts all galaxies lying behind the cluster core into long arcs. The lensed galaxies are all stretched along the cluster's center and some of them are multiply imaged. Those multiple images usually appear as a pair of images with a third — generally fainter — counter image, as is the case for the very distant object. The lensed galaxies are particularly numerous, as we are looking in between two mass clumps, in a saddle region where the magnification is quite large. Abell 2218 was used as a gravitational lens to discover the most distant known object in the universe as of 2004. The object, a galaxy some 13 billion years old, is seen from Earth as it would have been just 750 million years after the Big Bang. The color of the lensed galaxies is a function of their distances and types. The orange arc is an elliptical galaxy at moderate redshift (z=0.7). The blue arcs are star-forming galaxies at intermediate redshift (z=1-2.5). There is a pair of images in the lower part of the picture of the newly discovered star-forming galaxy at about redshift 7. - "NASA/IPAC Extragalactic Database". Results for Abell 2218. Retrieved 2006-09-18. - Abell, George O.; Corwin, Harold G., Jr.; Olowin, Ronald P. (May 1989). "A catalog of rich clusters of galaxies" (PDF). Astrophysical Journal Supplement Series. 70 (May 1989): 1–138. Bibcode:1989ApJS...70....1A. doi:10.1086/191333. ISSN 0067-0049. Retrieved March 13, 2012. - MSNBC: "Galaxy ranks as most distant object in cosmos" - firstname.lastname@example.org. "Hubble and Keck's newly discovered galaxy 'building block'". www.spacetelescope.org. Retrieved 2017-08-23. - Release about Abell 2218 at ESA/Hubble - Astronomy Picture of the Day - Abell 2218: A Galaxy Cluster Lens - 2010 June 20 \|This galaxy-related article is a stub. You can help Wikipedia by expanding it.\|	<urn:uuid:fffd4863-d7dd-4586-9f37-9007c3ef2a41>	2.84375	589	Knowledge Article	Science & Tech.	76.220295	95,578,368
1,900 feet deepMany of the most bizzare and/or fascinating creatures on Earth can be found near the bottom of the sea, far from the light of the sun that is such a big part of all living creatures on the surface. One of those is the extremely rare “black sea devil” anglerfish, which has only been observed a few times before, and never in its natural habitat. Researchers at the Monterey Bay Aquarium Research Institute in California changed that, thanks to a remote-controlled robotic submarine that dove to 1,900 feet of depth in the Monterey Canyon. There it captured the videos of a female Anglerfish. See for yourself: “This is the first time we’ve captured this fish on video in its habitat,” said Bruce Robison, a senior scientist at the Monterey Bay Aquarium Research Institute. “Anglerfish, like this Melanocetus, are among the most rarely seen of all deep-sea fishes.” Anglerfish are, to most people, monstrous-looking. The deep-sea predators are named and known for a worm-like appendage on their heads that emits light, which helps them attract prey into their toothy and angular gaping mouths.	<urn:uuid:699a7dc9-5cea-4b5b-82b4-9ccc73315cfe>	3.40625	260	News Article	Science & Tech.	45.585431	95,578,376
The study of comet plasma physics has long been a fascinating field of astronomical research and it has become more so after the flyby observations of Comet P/Giacobini-Zinner by the International Cometary Explorer (ICE) spacecraft in 1985 and the flotilla of space probes to Comet P/Halley in 1986. This point may be appreciated just by noting the dramatic surge in publications in space physics concerned with comet plasma. Furthermore, while the solar wind interaction with comets and the novel physical processes involved therein should be investigated in their own rights, comet comae also provide a natural laboratory for the simulations of many intriguing phenomena in astrophysical environments. Some of the most sophisticated magnetohydrodynamic (MHD) numerical simulations have indeed been carried out to study the morphologies and dynamics of comet plasmae. KeywordsSolar Wind Interplanetary Magnetic Field Solar Wind Plasma Solar Wind Proton Solar Wind Flow Unable to display preview. Download preview PDF.	<urn:uuid:7b4ccea4-c987-478f-8212-336d323bb473>	2.8125	195	Truncated	Science & Tech.	13.231385	95,578,395
Issue Date: July 28, 2008 Catalysts Under Pressure A team of researchers has recorded atomic-resolution transmission electron microscopy (TEM) images of catalyst particles (shown) while the solids were exposed to relatively high pressures of reactive gas (1 atm H2) and heated to 500 °C (Ultramicroscopy, DOI: 10.1016/j.ultramic.2008.04.014). The imaging experiment, which was conducted at 100 times greater pressure than in previous TEM studies, may lead to new ways of probing materials that undergo subtle but important structural changes as chemical reactions proceed on their surfaces. Generally, researchers aiming to record atomic-resolution TEM images conduct their experiments under high vacuum and at moderate temperatures because higher pressures and temperatures limit resolution and image quality. The usual imaging conditions, however, differ greatly from typical industrial catalytic reaction conditions, which may alter a catalyst's structure from an inactive to a catalytically active form. To get an up-close view of catalysts under demanding conditions, J. Fredrik Creemer of Delft University of Technology, in the Netherlands; Stig Helveg of catalyst manufacturer Haldor Topsøe, in Denmark; and coworkers designed a TEM-compatible microreactor and used it to probe a Cu/ZnO methanol-synthesis catalyst. While activating the catalyst at high temperature in hydrogen, the team directly observed the growth, structure, and evolution of copper nanocrystals with angstrom resolution on a subsecond timescale. - Chemical & Engineering News - ISSN 0009-2347 - Copyright © American Chemical Society	<urn:uuid:bfa20536-714f-4a68-8d36-093af9ef0a0a>	2.609375	339	Truncated	Science & Tech.	17.314859	95,578,405
R package ipdw provides the functionality to perform interpolation of georeferenced point data using inverse path distance weighting. Interpolation is accomplished in two steps. First, path distances are calculated from each georeferenced (measurement) point to each prediction point. Path distances, which honor barriers in the landscape, are calculated based on cell-to-cell movement through an underlying Raster object that represents movement cost. These path distances are subsequently used as interpolation weights. The two-step routine follows the order of operations described in Suominen et al. (2010) substituting the ESRI path distance algorithm with the gdistance wrapped version of the igraph adjacency algorithm. The ipdw package was developed with coastal marine applications in mind where path distances (as the fish swims) rather than Euclidean (as the crow flies) distances more accurately represent spatial connectivity. Interpolation of sparse grids in coastal areas otherwise end up bleeding through land areas. Stable version from CRAN or development version from GitHub install.packages('devtools') # package devtools needed devtools::install_github("jsta/ipdw") Joseph Stachelek and Christopher J. Madden (2015). Application of Inverse Path Distance weighting for high density spatial mapping of coastal water quality patterns. International Journal of Geographical Information Science preprint \| journal Tapio Suominen, Harri Tolvanen, and Risto Kalliola (2010). Surface layer salinity gradients and flow patterns in the archipelago coast of SW Finland, northern Baltic Sea. Marine Environmental Research journal	<urn:uuid:32f88b54-1ed1-4da1-8e4d-51ddedcf29a5>	2.765625	341	Product Page	Software Dev.	20.411231	95,578,406
You are here: Home Homestead Living Science Climate Change Facts Sheet Climate Change Facts Sheet by earthpolicy July 3, 2014, 8:10 am Stabilizing the earth’s climate depends on cutting carbon emissions fast. Here are some of the most alarming climate change facts. Global emissions of carbon dioxide (CO2)—the principal climate-altering greenhouse gas—come largely from burning coal, oil, and natural gas. Coal, mainly used for electricity generation, accounts for 44 percent of global fossil-fuel-related CO2 emissions. Oil, used primarily for transportation, accounts for 36 percent of CO2 emissions. Natural gas, used for electricity and heating, accounts for the remaining 20 percent of CO2 emissions. Worldwide, fossil fuel subsidies topped $620 billion in 2011, while renewable energy received just $88 billion in subsidies. Since the Industrial Revolution, the planet has warmed by roughly one degree. 2013 marked the 37th consecutive year of above-average temperatures. Fully 4 billion people alive today have never experienced a year that was cooler than last century’s average. If we continue with business as usual, burning ever more oil, coal, and natural gas, the global average temperature is projected to rise some 11 degrees Fahrenheit (6 degrees Celsius) by the end of this century. In addition to more widespread drought and more numerous wildfires, climate change brings more extreme heat waves. In the last decade, daily record high temperatures outnumbered record lows in the United States two to one, and that ratio is increasing. Crop ecologists have a rule of thumb that each 1-degree-Celsius rise in temperature above the norm during the growing season lowers wheat, rice, and corn yields by 10 percent. Field tests show that this may be conservative. This century, as waters warm and ice continues to melt, seas are projected to rise some 2 meters (6 feet), inundating coastal cities worldwide, such as New York, London, and Cairo, and agricultural hotspots, like rice-growing river deltas. Earth Policy Institute’s Plan B shows the steps needed to cut global carbon emissions 80 percent. Cutting carbon emissions involves shifting from fossil fuels to renewable sources of energy, dramatically ramping up efficiency, and protecting and restoring forests and other natural systems. Data and additional resources available at www.earth-policy.org. See more Previous article The DIY Solar Charger: 7 Plans Next article Blogger ‘The Blonde Vegan’ Gets the Vegan Diet Really, Really Wrong One Ping Pingback:Sustainablog \| Jeff McIntire-Strasburg has been blogging a greener world via sustainablog since 2003! Leave a Reply Cancel reply Your email address will not be published. Required fields are marked Comment Name Email * Website Save my name, email, and website in this browser for the next time I comment. Upload a photo / attachment to this comment (PNG, JPG, GIF - 6 MB Max File Size): (Allowed file types: jpg, gif, png, maximum file size: 6MB.	<urn:uuid:e31e7277-4602-48a2-9787-261287c5571d>	3.203125	620	Truncated	Science & Tech.	38.215282	95,578,407
When species’ ranges meet: assessing differences in habitat selection between sympatric large carnivores Differentiation in habitat selection among sympatric species may depend on niche partitioning, species interactions, selection mechanisms and scales considered. In a mountainous area in Sweden, we explored hierarchical habitat selection in Global Positioning System-collared individuals of two sympatric large carnivore species; an obligate predator, the Eurasian lynx (Lynx lynx), and a generalist predator and scavenger, the wolverine (Gulo gulo). Although the species’ fundamental niches differ widely, their ranges overlap in this area where they share a prey base and main cause of mortality. Both lynx and wolverines selected for steep and rugged terrain in mountainous birch forest and in heaths independent of scale and available habitats. However, the selection of lynx for their preferred habitats was stronger when they were forming home ranges and they selected the same habitats within their home ranges independent of home range composition. Wolverines displayed a greater variability when selecting home ranges and habitat selection also varied with home range composition. Both species selected for habitats that promote survival through limited encounters with humans, but which also are rich in prey, and selection for these habitats was accordingly stronger in winter when human activity was high and prey density was low. We suggest that the observed differences between the species result primarily from different foraging strategies, but may also depend on differences in ranging and resting behaviour, home range size, and relative density of each species. Our results support the prediction that sympatric carnivores with otherwise diverging niches can select for the same resources when sharing main sources of food and mortality. KeywordsInterspecific interaction Human disturbance Eurasian lynx Wolverine Reindeer The study was funded by the Swedish Environmental Protection Agency, the Norwegian Directorate for Nature Management, the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas), the World Wide Fund for Nature (Sweden), and the private foundations Olle och Signhild Engkvists Stiftelser and Marie-Claire Cronstedts Stiftelse. We thank Peter Segerström and Tom Wiklund for field assistance and Jon Arnemo for veterinary assistance. We thank Gustaf Samelius, Johan Månsson, Tomas Willebrand, and an anonymous reviewer for valuable comments on earlier drafts. - Arnemo JM, Evans A, Fahlman Å (2011) Biomedical protocols for free-ranging brown bears, gray wolves, wolverines and lynx. http://www.rovviltportalen.no/content.ap?thisId=500039688. Accessed 29 Jan 2011 - Boles BK (1977) Predation by wolves on wolverine. Can Field Nat 91:68–69Google Scholar - Boulinier T, Mariette M, Doligez B, Danchin É (2008) Choosing where to breed: breeding habitat choice. In: Danchin É, Giraldeau L-A, Cézilly F (eds) Behavioural ecology. Oxford University Press, New York, pp 285–321Google Scholar - Giraldeau L-A (2008) Solitary foraging strategies. In: Danchin É, Giraldeau L-A, Cézilly F (eds) Behavioural ecology. Oxford University Press, New York, pp 233–255Google Scholar - Haglund B (1966) De stora rovdjurens vintervanor Ι. (Winter habits of the lynx (Lynx lynx L.) and wolverine (Gulo gulo L.) as revealed by tracking in the snow). Viltrevy 4:81–310Google Scholar - Hall LS, Krausman PR, Morrison ML (1997) The habitat concept and a plea for standard terminology. Wildl Soc Bull 25:173–182Google Scholar - Mattisson J, Odden J, Nilsen EB, Linnell JDC, Persson J, Andrén H (2011b) Factors affecting Eurasian lynx kill rates on semi-domestic reindeer in northern Scandinavia: can ecological research contribute to the development of a fair compensation system? Biol Conserv 144:3009–3017CrossRefGoogle Scholar - Pedersen VA, Linnell JDC, Andersen R, Andrén H, Linden M, Segerström P (1999) Winter lynx Lynx lynx predation on semi-domestic reindeer Rangifer tarandus in northern Sweden. Wildl Biol 5:203–211Google Scholar - R Development Core Team (2009) R: a language and environment for statistical computing. R Foundation for Statistical Computing, ViennaGoogle Scholar - Rodgers AR, Carr AP, Beyer HL, Smith L, Kie JG (2007) HRT: home range tools for ArcGIS. In: Ontario Ministry of Natural Resources, Centre for Northern Forest Ecosystem Research, Thunder Bay, Ontario, CanadaGoogle Scholar - Sokal RR, Rohlf FJ (1981) Biometry.The principles and practice of statistics in biological research, 2nd edn. Freeman, San FranciscoGoogle Scholar - Samelius G, Alisauskas RT, Lariviere S, Bergman C, Hendricson CJ, Phipps K, Wood C (2002) Foraging behaviours of wolverines at a large arctic goose colony. Arctic 55:148–150Google Scholar	<urn:uuid:e9f82346-a3f4-4be3-97d3-b2b20158b0b7>	2.8125	1,148	Academic Writing	Science & Tech.	32.108697	95,578,417
Report on Heard (Australia) — February 1998 Bulletin of the Global Volcanism Network, vol. 23, no. 2 (February 1998) Managing Editor: Richard Wunderman. Heard (Australia) No evidence of recent activity in March Please cite this report as: Global Volcanism Program, 1998. Report on Heard (Australia). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 23:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199802-234010. 53.106°S, 73.513°E; summit elev. 2745 m All times are local (unless otherwise noted) During 18-21 March geologists sampled Holocene lava flows on Heard Island. On beaches of the N Laurens Peninsula, they found fresh pumice ranging in size up to about 20 x 20 cm . The pumice was concentrated among other storm- transported debris a little distance above the normal surf zone and appeared to have been deposited by wave action. Light creamy green to pale gray in color, the pumice had angular, ovoid or flattened shapes and contained predominantly microphenocrysts and occasional phenocrysts visible to the naked eye. Lithic fragments were not observed. On Heard Island, Big Ben's summit was usually obscured by clouds. The summit was visible on 20 March, however, and at this time no evidence of recent volcanic activity was observed at Mawson Peak, Big Ben's recently active crater (figure 3). Similarly no plume was seen coming from Heard when McDonald vented steam in early April. In accord with these observations, scientists inferred that the December 1996-January 1997 volcanic activity attributed to Heard actually denoted activity at McDonald. References. LeMasurier, W.E., and Thompson, J.W., primary eds., 1990, Volcanoes of the Antarctic Plate and Southern Oceans, Antarctic Research Series: American Geophysical Union, Washington, D. C. (ISBN 0066-4634). Collerson, K. D., 1997, Field studies at Heard and McDonald Island in March 1997: unpublished Australian National Antarctic Research Expedition (ANARE) report. Geologic Background. Heard Island on the Kerguelen Plateau in the southern Indian Ocean consists primarily of the emergent portion of two volcanic structures. The large glacier-covered composite basaltic-to-trachytic cone of Big Ben comprises most of the island, and the smaller Mt. Dixon volcano lies at the NW tip of the island across a narrow isthmus. Little is known about the structure of Big Ben volcano because of its extensive ice cover. The historically active Mawson Peak forms the island's 2745-m high point and lies within a 5-6 km wide caldera breached to the SW side of Big Ben. Small satellitic scoria cones are mostly located on the northern coast. Several subglacial eruptions have been reported in historical time at this isolated volcano, but observations are infrequent and additional activity may have occurred. Information Contacts: Kenneth Collerson, Department of Earth Sciences, University of Queensland, Brisbane, Queensland 4072, Australia; Kevin Kiernan, Department of Geography and Environmental Sciences, University of Newcastle, Newcastle, New South Wales 2300, Australia; Richard Williams, Australian Antarctic Division, Channel Highway, Hobart, Tasmania, Australia; Andrew Tupper, Northern Territory Regional Forecasting Centre, Bureau of Meteorology, P. O. Box 735, Darwin, Northern Territory 0801, Australia.	<urn:uuid:85143318-e713-47a2-a05e-8e86c7d1e078>	2.84375	746	Knowledge Article	Science & Tech.	46.151928	95,578,440
A new computer simulation conducted at the University of Bristol (UB) and University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science has revealed the epic, ocean-spanning journeys travelled by millimetre-sized coral larvae through the world's seas. The pathways traveled by >14 million modeled coral larval over a one-year period using the Connectivity Modeling System developed by Dr. Claire Paris at the University of Miami. Note the empty no-man's-land that larvae have difficulty breaching -- this is the East Pacific Dispersal Barrier. Credit: S. Wood/Univ. of Bristol The study, published in Global Ecology and Biogeography, is the first to recreate the oceanic paths along which corals disperse globally, and will eventually aid predictions of how coral reef distributions may shift with climate change. Coral reefs are under increasing threat from the combined pressures of human activity, natural disturbances and climate change. It has been suggested that coral may respond to these changing conditions by shifting to more favourable refuges, but their ability to do this will depend on the ocean currents. Sally Wood, a Ph.D. candidate at UB, explains: "Dispersal is an extremely important process for corals. As they are attached to the seafloor as adults, the only way they can escape harmful conditions or replenish damaged reefs is by releasing their young to the mercy of the ocean currents." Where these intrepid explorers end up is therefore an important question for coral reef conservation. However, tracking the movement of such tiny larvae in the vast oceans is an impossible task. "This is where computer simulation comes in," adds Wood. Collaborating across the pond, Wood used the Connectivity Modeling System (CMS) developed by Dr. Claire Paris, associate professor of Applied Marine Physics at UM to identify the billions of paths taken. This larval migration model had been tested in a previous study against the reef-building coral Montastraea annularis in the Caribbean, where consensus between modeled estimates of genetic structure were found. "Simulating an unprecedented number of mass spawning events from all known shallow reefs in the global ocean proved essential to identifying critical long dispersal distance events that promote the establishment of new coral colonies. What we found using the CMS are rare long distance dispersers that are thought to contribute to species persistence in isolated coral reefs, and to geographic range shifts during environmental changes," said Paris. Some of the results yielded by the team were surprising. While the majority of simulated larvae settled close to home, others travelled as far as 9,000 km., almost the entire width of the Pacific Ocean. When considered over multiple generations, this means that corals are able to cross entire ocean basins, using islands and coastlines as 'stepping stones.' However, a few places proved too distant for all but the hardiest of larvae: Coral in the tropical eastern Pacific are almost entirely cut off from those on islands of the central Pacific by a daunting 5000 km of open ocean. Geographically isolated reefs such as these may be particularly vulnerable, as they are not stocked with external recruits as frequently. The model captured the start of the coral larvae's journey to its survival, and further work is ongoing to complete the story. Even after overcoming the trials of the open ocean, coral larvae arriving at a suitable location must first negotiate a 'wall of mouths' to settle on the reef face, and then compete fiercely for the space to thrive and grow. Development of the CMS was funded through the NSF-RAPID program (OCE-1048697) to CBP. The University of Miami's mission is to educate and nurture students, to create knowledge, and to provide service to our community and beyond. Committed to excellence and proud of the diversity of our University family, we strive to develop future leaders of our nation and the world. Founded in the 1940's, the Rosenstiel School of Marine & Atmospheric Science has grown into one of the world's premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. For more information, please visit http://www.rsmas.miami.edu. Paper: 'Modeling dispersal and connectivity of broadcast spawning corals at the global scale', by S. Wood, C.B. Paris, A. Ridgwell, & E.J. Hendy. Global Ecology and Biogeography (2013). Barbra Gonzalez \| EurekAlert! Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany 25.06.2018 \| Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF Dry landscapes can increase disease transmission 20.06.2018 \| Forschungsverbund Berlin e.V. For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy. Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 16.07.2018 \| Physics and Astronomy 16.07.2018 \| Life Sciences 16.07.2018 \| Earth Sciences	<urn:uuid:853b6db8-4c2e-41b1-b647-e8e47a803444>	3.84375	1,614	Content Listing	Science & Tech.	38.98293	95,578,465
This article needs additional citations for verification. (February 2009) (Learn how and when to remove this template message) Fluid mechanics is a branch of physics concerned with the mechanics of fluids (liquids, gases, and plasmas) and the forces on them. Fluid mechanics has a wide range of applications, including mechanical engineering, civil engineering, chemical engineering, biomedical engineering, geophysics, astrophysics, and biology. Fluid mechanics can be divided into fluid statics, the study of fluids at rest; and fluid dynamics, the study of the effect of forces on fluid motion. It is a branch of continuum mechanics, a subject which models matter without using the information that it is made out of atoms; that is, it models matter from a macroscopic viewpoint rather than from microscopic. Fluid mechanics, especially fluid dynamics, is an active field of research with many problems that are partly or wholly unsolved. Fluid mechanics can be mathematically complex, and can best be solved by numerical methods, typically using computers. A modern discipline, called computational fluid dynamics (CFD), is devoted to this approach to solving fluid mechanics problems. Particle image velocimetry, an experimental method for visualizing and analyzing fluid flow, also takes advantage of the highly visual nature of fluid flow. - 1 Brief history - 2 Main branches - 3 Relationship to continuum mechanics - 4 Assumptions - 5 Navier–Stokes equations - 6 Inviscid and Viscous Fluids - 7 Newtonian versus non-Newtonian fluids - 8 See also - 9 Notes - 10 References - 11 Further reading - 12 External links The study of fluid mechanics goes back at least to the days of ancient Greece, when Archimedes investigated fluid statics and buoyancy and formulated his famous law known now as the Archimedes' principle, which was published in his work On Floating Bodies – generally considered to be the first major work on fluid mechanics. Rapid advancement in fluid mechanics began with Leonardo da Vinci (observations and experiments), Evangelista Torricelli (invented the barometer), Isaac Newton (investigated viscosity) and Blaise Pascal (researched hydrostatics, formulated Pascal's law), and was continued by Daniel Bernoulli with the introduction of mathematical fluid dynamics in Hydrodynamica (1739). Inviscid flow was further analyzed by various mathematicians (Leonhard Euler, Jean le Rond d'Alembert, Joseph Louis Lagrange, Pierre-Simon Laplace, Siméon Denis Poisson) and viscous flow was explored by a multitude of engineers including Jean Léonard Marie Poiseuille and Gotthilf Hagen. Further mathematical justification was provided by Claude-Louis Navier and George Gabriel Stokes in the Navier–Stokes equations, and boundary layers were investigated (Ludwig Prandtl, Theodore von Kármán), while various scientists such as Osborne Reynolds, Andrey Kolmogorov, and Geoffrey Ingram Taylor advanced the understanding of fluid viscosity and turbulence. Fluid statics or hydrostatics is the branch of fluid mechanics that studies fluids at rest. It embraces the study of the conditions under which fluids are at rest in stable equilibrium; and is contrasted with fluid dynamics, the study of fluids in motion. Hydrostatics offers physical explanations for many phenomena of everyday life, such as why atmospheric pressure changes with altitude, why wood and oil float on water, and why the surface of water is always level and horizontal whatever the shape of its container. Hydrostatics is fundamental to hydraulics, the engineering of equipment for storing, transporting and using fluids. It is also relevant to some aspect of geophysics and astrophysics (for example, in understanding plate tectonics and anomalies in the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields. Fluid dynamics is a subdiscipline of fluid mechanics that deals with fluid flow—the science of liquids and gases in motion. Fluid dynamics offers a systematic structure—which underlies these practical disciplines—that embraces empirical and semi-empirical laws derived from flow measurement and used to solve practical problems. The solution to a fluid dynamics problem typically involves calculating various properties of the fluid, such as velocity, pressure, density, and temperature, as functions of space and time. It has several subdisciplines itself, including aerodynamics (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). Fluid dynamics has a wide range of applications, including calculating forces and moments on aircraft, determining the mass flow rate of petroleum through pipelines, predicting evolving weather patterns, understanding nebulae in interstellar space and modeling explosions. Some fluid-dynamical principles are used in traffic engineering and crowd dynamics. Relationship to continuum mechanics Fluid mechanics is a subdiscipline of continuum mechanics, as illustrated in the following table. The study of the physics of continuous materials The study of the physics of continuous materials with a defined rest shape. Describes materials that return to their rest shape after applied stresses are removed. Describes materials that permanently deform after a sufficient applied stress. The study of materials with both solid and fluid characteristics. The study of the physics of continuous materials which deform when subjected to a force. \|Non-Newtonian fluids do not undergo strain rates proportional to the applied shear stress.\| \|Newtonian fluids undergo strain rates proportional to the applied shear stress.\| In a mechanical view, a fluid is a substance that does not support shear stress; that is why a fluid at rest has the shape of its containing vessel. A fluid at rest has no shear stress. The assumptions inherent to a fluid mechanical treatment of a physical system can be expressed in terms of mathematical equations. Fundamentally, every fluid mechanical system is assumed to obey: For example, the assumption that mass is conserved means that for any fixed control volume (for example, a spherical volume) – enclosed by a control surface – the rate of change of the mass contained in that volume is equal to the rate at which mass is passing through the surface from outside to inside, minus the rate at which mass is passing from inside to outside. This can be expressed as an equation in integral form over the control volume. The continuum assumption is an idealization of continuum mechanics under which fluids can be treated as continuous, even though, on a microscopic scale, they are composed of molecules. Under the continuum assumption, macroscopic (observed/measurable) properties such as density, pressure, temperature, and bulk velocity are taken to be well-defined at "infinitesimal" volume elements -- small in comparison to the characteristic length scale of the system, but large in comparison to molecular length scale. Fluid properties can vary continuously from one volume element to another and are average values of the molecular properties. The continuum hypothesis can lead to inaccurate results in applications like supersonic speed flows, or molecular flows on nano scale. Those problems for which the continuum hypothesis fails, can be solved using statistical mechanics. To determine whether or not the continuum hypothesis applies, the Knudsen number, defined as the ratio of the molecular mean free path to the characteristic length scale, is evaluated. Problems with Knudsen numbers below 0.1 can be evaluated using the continuum hypothesis, but molecular approach (statistical mechanics) can be applied for all ranges of Knudsen numbers. The Navier–Stokes equations (named after Claude-Louis Navier and George Gabriel Stokes) are differential equations that describe the force balance at a given point within a fluid. For an incompressible fluid with vector velocity field , the Navier–Stokes equations are These differential equations are the analogues for deformable materials to Newton's equations of motion for particles, the Navier–Stokes equations describe changes in momentum (force) in response to pressure and viscosity, parameterized, here, by the kinematic viscosity . Occasionally, body forces, such as the gravitational force or Lorentz force are added to the equations. Solutions of the Navier–Stokes equations for a given physical problem must be sought with the help of calculus. In practical terms only the simplest case can be solved exactly in this way. These cases generally involve non-turbulent, steady flow in which the Reynolds number is small. For more complex cases, especially those involving turbulence, such as global weather systems, aerodynamics, hydrodynamics and many more, solutions of the Navier–Stokes equations can currently only be found with the help of computers. This branch of science is called computational fluid dynamics. Inviscid and Viscous Fluids An inviscid fluid has no viscosity, . In practice, an inviscid flow is an idealization, one that facilitates mathematical treatment. In fact, purely inviscid flows are only known to be realized in the case of superfluidity. Otherwise, fluids are generally viscous, a property that is often most important within a boundary layer near a solid surface, where the flow must match onto the no-slip condition at the solid. In some cases, the mathematics of a fluid mechanical system can be treated by assuming that the fluid outside of boundary layers is inviscid, and then matching its solution onto that for a thin laminar boundary layer. For fluid flow over a porous boundary, the fluid velocity can be discontinuous between the free fluid and the fluid in the porous media (this is related to the Beavers and Joseph condition). Further, it is useful at low subsonic speeds to assume that a gas is incompressible — that is, the density of the gas does not change even though the speed and static pressure change. Newtonian versus non-Newtonian fluids A Newtonian fluid (named after Isaac Newton) is defined to be a fluid whose shear stress is linearly proportional to the velocity gradient in the direction perpendicular to the plane of shear. This definition means regardless of the forces acting on a fluid, it continues to flow. For example, water is a Newtonian fluid, because it continues to display fluid properties no matter how much it is stirred or mixed. A slightly less rigorous definition is that the drag of a small object being moved slowly through the fluid is proportional to the force applied to the object. (Compare friction). Important fluids, like water as well as most gases, behave – to good approximation – as a Newtonian fluid under normal conditions on Earth. By contrast, stirring a non-Newtonian fluid can leave a "hole" behind. This will gradually fill up over time – this behaviour is seen in materials such as pudding, oobleck, or sand (although sand isn't strictly a fluid). Alternatively, stirring a non-Newtonian fluid can cause the viscosity to decrease, so the fluid appears "thinner" (this is seen in non-drip paints). There are many types of non-Newtonian fluids, as they are defined to be something that fails to obey a particular property – for example, most fluids with long molecular chains can react in a non-Newtonian manner. Equations for a Newtonian fluid The constant of proportionality between the viscous stress tensor and the velocity gradient is known as the viscosity. A simple equation to describe incompressible Newtonian fluid behaviour is - is the shear stress exerted by the fluid ("drag") - is the fluid viscosity – a constant of proportionality - is the velocity gradient perpendicular to the direction of shear. For a Newtonian fluid, the viscosity, by definition, depends only on temperature and pressure, not on the forces acting upon it. If the fluid is incompressible the equation governing the viscous stress (in Cartesian coordinates) is - is the shear stress on the face of a fluid element in the direction - is the velocity in the direction - is the direction coordinate. If the fluid is not incompressible the general form for the viscous stress in a Newtonian fluid is where is the second viscosity coefficient (or bulk viscosity). If a fluid does not obey this relation, it is termed a non-Newtonian fluid, of which there are several types. Non-Newtonian fluids can be either plastic, Bingham plastic, pseudoplastic, dilatant, thixotropic, rheopectic, viscoelastic. In some applications another rough broad division among fluids is made: ideal and non-ideal fluids. An Ideal fluid is non-viscous and offers no resistance whatsoever to a shearing force. An ideal fluid really does not exist, but in some calculations, the assumption is justifiable. One example of this is the flow far from solid surfaces. In many cases the viscous effects are concentrated near the solid boundaries (such as in boundary layers) while in regions of the flow field far away from the boundaries the viscous effects can be neglected and the fluid there is treated as it were inviscid (ideal flow). When the viscosity is neglected, the term containing the viscous stress tensor in the Navier–Stokes equation vanishes. The equation reduced in this form is called the Euler equation. - Applied mechanics - Bernoulli's principle - Communicating vessels - Computational fluid dynamics - Secondary flow - Different types of boundary conditions in fluid dynamics - Batchelor (1967), p. 74. - Kundu, P.K., Cohen, I.M., & Hu, H.H., Fluid Mechanics, Chapter 10, sub-chapter 1 - Batchelor (1967), p. 145. - Batchelor, George K. (1967), An Introduction to Fluid Dynamics, Cambridge University Press, ISBN 0-521-66396-2 - Falkovich, Gregory (2011), Fluid Mechanics (A short course for physicists), Cambridge University Press, ISBN 978-1-107-00575-4 - Kundu, Pijush K.; Cohen, Ira M. (2008), Fluid Mechanics (4th revised ed.), Academic Press, ISBN 978-0-12-373735-9 - Currie, I. G. (1974), Fundamental Mechanics of Fluids, McGraw-Hill, Inc., ISBN 0-07-015000-1 - Massey, B.; Ward-Smith, J. (2005), Mechanics of Fluids (8th ed.), Taylor & Francis, ISBN 978-0-415-36206-1 - White, Frank M. (2003), Fluid Mechanics, McGraw–Hill, ISBN 0-07-240217-2 - Nazarenko, Sergey (2014), Fluid Dynamics via Examples and Solutions, CRC Press (Taylor & Francis group), ISBN 978-1-43-988882-7 - Free Fluid Mechanics books - Annual Review of Fluid Mechanics - CFDWiki – the Computational Fluid Dynamics reference wiki. - Educational Particle Image Velocimetry – resources and demonstrations	<urn:uuid:431f8a7f-7d36-4b90-9578-d27f04181e90>	3.453125	3,173	Knowledge Article	Science & Tech.	31.874329	95,578,476
How To Write a Proof - Proving Parallel Lines - YouTube Published on Oct 7, 2013 Guess You Like How To Write a Proof for Parallel Lines 10 Places Science Can't Explain The REAL Answer To The Viral Chinese Math Problem "How Old Is The Captain?" The 5 LESSONS In Life People Learn TOO LATE Proving Parallel Lines With Two Column Proofs - Geometry, Practice Problems What are the Different Angles Formed by a Transversal with Two Parallel Lines? HARD Google Interview Question - The 25 Horses Puzzle Two-Column Proof Practice I Proving Parallel Lines with Angle Relationships What is 0 to the power of 0? Using SSS, SAS, ASA, AAS, and HL to prove two triangles are congruent How To Regrip A Golf Club \| Golf Pride Can You Solve The Hardest Easy Geometry Problem? Where Do Parallel Lines Intersect? This Is How We Know Earth Isn't Flat Writing a Proof for Parallel Lines What is 6÷2(1+2) = ? The Correct Answer Explained Angles, parallel lines, & transversals (Hindi) \| Lines and Angles \| Class 7 (India) \| Khan Academy 5 Tips to Solve Any Geometry Proof by Rick Scarfi Why √a√b isn't always equal to √ab Get The Newest Version 2018 TubeMate ALL RIGHTS RESERVED.	<urn:uuid:e9e64374-641c-4eca-b40b-985afbde7fec>	3.671875	313	Content Listing	Science & Tech.	51.184412	95,578,489
Stephen Hawking may have just solved one of the most vexing mysteries in physics — the "information paradox." Einstein's theory of general relativity predicts that the physical information about material gobbled up by a black hole is destroyed, but the laws of quantum mechanics stipulate that information is eternal. Therein lies the paradox. Hawking — working with Malcolm Perry, of the University of Cambridge in England, and Harvard University's Andrew Stromberg — has come up with a possible solution: The quantum-mechanical information about infalling particles doesn't actually make it inside the black hole. "I propose that the information is stored not in the interior of the black hole, as one might expect, but on its boundary, the event horizon," Stephen Hawking said during a talk Tuesday at the Hawking Radiation conference, which is being held at the KTH Royal Institute of Technology in Stockholm, Sweden. The information is stored at the boundary as two-dimensional holograms known as "super translations," he explained. But you wouldn't want super translations, which were first introduced as a concept in 1962, to back up your hard drive. "The information about ingoing particles is returned, but in a chaotic and useless form," Hawking said. "For all practical purposes, the information is lost." Hawking also discussed black holes — whose gravitational pull is so intense that nothing, not even light, can escape once it passes the event horizon — during a lecture Monday in Stockholm. It's possible that black holes could actually be portals to other universes, he said. "The hole would need to be large, and if it was rotating, it might have a passage to another universe. But you couldn't come back to our universe," Hawking said at the lecture, according to a KTH Royal Institute of Technology statement. "So, although I'm keen on spaceflight, I'm not going to try that." - Iron-rich Minerals on Mars Could Contain Life's Fatty Acids - Telescope Upgrade Produces Stunningly Clear Views of Space - Twin Exoplanets Look Alike, Act Alike … But Have Completely Different Origins - How 'Electric Microbes' Could Generate Power (And More) for Space Missions (Video) This article originally published at Space.com here	<urn:uuid:1034d693-3767-4662-b8d1-62ff359afbfd>	2.921875	472	Truncated	Science & Tech.	32.658303	95,578,506
WGS 84 — Past, Present and Future The World Geodetic System (WGS) was conceived as a practical geodetic reference system that maintains consistency with the best scientific terrestrial reference system at the time but also retains some stability. It has evolved from its beginnings as WGS 60 to its present manifestation as WGS 84. A significantly improved Earth Gravitational Model and global geoid were released in 1996, and the realization of the WGS 84 reference frame is consistent with the International Terrestrial Reference Frame (ITRF) 1994 at the 5-cm level. Evaluations of WGS 84 relative to ITRF94 have been made by comparing International GPS Service (IGS) GPS orbits with the National Imagery and Mapping Agency’s precise orbits and by computing WGS 84 positions for a globally distributed set of IGS stations with known ITRF94 coordinates. The results indicate that there is no practical difference between ITRF94 and WGS 84 for mapping, charting, navigation and many survey applications. KeywordsGlobal Position System Global Position System Orbit Geodetic Reference System International Terrestrial Reference Frame International Earth Rotation Service Unable to display preview. Download preview PDF. - Cunningham, J. and Curtis, V.L., WGS 84 Coordinate Validation and Improvement for the NIMA and Air Force GPS Tracking Stations, NSWCDD/TR-96/201, Nov. 1996, Dahlgren, Virginia.Google Scholar - Defense Mapping Agency, Technical Report, Department of Defense World Geodetic System 1984, DMA TR 8350.2, Second Ed., 1 Sept. 1991.Google Scholar - Lemoine, FG., Smith, D.E., Smith, R, Kunz, L, Pavlis, EC, Pavlis, N.K., Klosko, SM, Chinn, D.S., Torrence, M.H., Williamson, R.G., Cox, CM, Rachlin, K.E, Wang, Y.M, Kenyon, SC, Salman, R, Trimmer, R, Rapp, RH, and Nerem, RS, The Development of the NASA/GSFC and NIMA Joint Geopotential Model, Proc. of the International Symposium of Gravity, Geoid, and Marine Gravity 1996 (GraGeoMar96), Tokyo, Japan, 30 Sep-5 Oct 1996 (in preparation).Google Scholar - Malys, S. and Slater, J, Maintenance and Enhancement of the World Geodetic System 1984, Proc. ION GPS-94, Salt Lake City, Utah, Sept. 1994, pp. 17–24.Google Scholar - McCarthy, D.D., Ed, IERS Standards (1992), IERS Technical Note 13, July 1992, Observatoire de Paris, France.Google Scholar - Moritz, H, “Geodetic Reference System 1980”, Bulletin Geodesique, Vol. 54, No. 3, Paris, France, 1980.Google Scholar - Swift, ER, Gouldman, M.W, Merrigan, M.J. and Curtis, V.L., GPS Orbit Estimation and Station Coordinate Improvement Using a 1992 IGS Campaign Data Set, NSWSCDD/TR-94/267, Oct. 1994, Dahlgren, Viriginia.Google Scholar	<urn:uuid:7bc690c7-4e2a-4d91-a077-3d603dd5e25c>	2.71875	692	Truncated	Science & Tech.	65.515128	95,578,521
I can never understand how I feel about robots. On one hand, they creep me the hell out: But then on the other hand, they do work sometimes work for humanities benefit. You know, like recording data on lava flowing into the ocean. Blockchain and cryptocurrency news minus the bullshit. Visit Hard Fork. This lava is coming from Hawaii’s Kīlauea Volcano, which has caused, and is still causing, devastation and suffering in its vicinity. You can find more information about that on the USGS site. The project will last about three weeks and is being undertaken in conjunction with the University of Hawai’i at Hilo, MIT, and the US Geological Survey’s Hawaiian Volcano Observatory. The robots themselves are collecting as much data as possible, including water temperature, oxygen levels, pH levels, underwater acoustics, and more. Data from this project will help researchers understand the impact of volcanic eruptions on the environment, including on the air quality on the Hawaiian islands. If you’d like to help out those impacted by the Kīlauea Volcano, Hawaii News Now has a guide here.	<urn:uuid:7bc32d86-96fd-4b68-9f5c-c7fc9700ca25>	2.578125	239	News Article	Science & Tech.	46.637615	95,578,524
Desert bugs raise hopes of finding life on Mars Dormant life has been discovered alive and well in one of the driest corners of Earth. A freak shower in the world’s driest desert has surprised scientists by waking up sleeping microbes – and at the same time increased the chances of finding life on Mars. The US team discovered incredibly hardy bacteria that can lie dormant in the soil for decades without a hint of water. When it unexpectedly rained in their habitat, the most arid corner of South America’s Atacama desert, they bounced back into life. Planetary scientist Dr Dirk Schulze-Makuch, from Washington State University, said: “It has always fascinated me to go to the places where people don’t think anything could possibly survive and discover that life has somehow found a way to make it work. “Jurassic Park references aside, our research tell us that if life can persist in Earth’s driest environment there is a good chance it could be hanging in there on Mars in a similar fashion.” The researchers took soil samples from six different locations in the Atacama desert between 2015 and 2017. Microbes had been found in the desert before, but it was not clear if they were original residents or dying vestiges of life blown in by the wind. The answer came after an extremely rare rain shower triggered an explosion of biological activity. Genetic tests revealed several indigenous species of bacteria that had adapted to live in the harsh environment. A return trip to the Atacama in 2016 and 2017 revealed that the same bugs were gradually reverting to a dormant state as the soil around them dried up. Dr Schulze-Makuch said: “In the past researchers have found dying organisms near the surface and remnants of DNA but this is really the first time that anyone has been able to identify a persistent form of life living in the soil of the Atacama desert. “We believe these microbial communities can lay dormant for hundreds or even thousands of years in conditions very similar to what you would find on a planet like Mars and then come back to life when it rains.” Billions of years ago Mars had oceans and lakes where early life forms may have thrived. As the planet dried up and grew colder, the Martian bugs could have survived in much the same way as their Atacama counterparts, the scientists believe. “If life ever evolved on Mars, our research suggests it could have found a sub-surface niche beneath today’s severely hyper-arid surface,” Dr Schulze-Makuch added. A European rover due to land on Mars in 2021 as part of the ExoMars mission will drill two metres into the soil to look for signs of life. The findings are published in the journal Proceedings of the National Academy of Sciences.	<urn:uuid:815c44e8-bb79-41bc-a603-6c9bef2a4faa>	3.375	602	News Article	Science & Tech.	43.299044	95,578,526
Some four-winged insect orders, such as the Lepidoptera, have developed a wide variety of morphological wing coupling mechanisms in the imago which render these taxa as "functionally dipterous" (effectively two-winged) for efficient insect flight. All, but the most basal forms, exhibit this wing coupling.:4266 The mechanisms are of three different types - jugal, frenulo-retinacular and amplexiform. Jugal wing coupling The more primitive groups of moth have an enlarged lobe-like area near the basal posterior margin, i.e. at the base of the forewing, called jugum, that folds under the hindwing in flight.:631-664 Frenulo-retinacular wing coupling Other groups of moth have a frenulum on the hindwing that hooks under a retinaculum on the forewing. The retinaculum is a hook or tuft on the underside of the forewing of some moths. Along with the frenulum, a spine at the base of the forward or costal edge of the hindwing, it forms a coupling mechanism for the front and rear wings of the moth. Amplexiform wing coupling In the butterflies[a] and in the Bombycoidea[b] there is no arrangement of frenulum and retinaculum to couple the wings. Instead, an enlarged humeral area of the hindwing is broadly overlapped by the forewing. Despite the absence of a specific mechanical connection, the wings overlap and operate in phase. The power stroke of the forewing pushes down the hindwing in unison. This type of coupling is a variation of frenate type but where the frenulum and retinaculum are completely lost. - Dudley, Robert (2002). The biomechanics of insect flight: form, function, evolution (Reprint, illustrated ed.). Princeton University Press. p. 476. ISBN 978-0-691-09491-5. - Stocks, Ian (2008). "Wing coupling". In Capinera, John L. Encyclopedia of Entomology. Gale virtual reference library. 4 (2 ed.). Springer Reference. p. 4345. ISBN 978-1-4020-6242-1. Retrieved 14 November 2010. - Scoble, M.J. (1995). The Lepidoptera: form, function and diversity (Reprint (illustrated) ed.). Oxford University Press. p. 416. ISBN 978-0-19-854952-9. Retrieved 14 November 2010. Subsec. "Wing coupling". Pp 56-60. - Powell, Jerry A. (2009). "Lepidoptera". In Resh, Vincent H.; Cardé, Ring T. Encyclopedia of Insects (2 (illustrated) ed.). Academic Press. p. 1132. ISBN 978-0-12-374144-8. Retrieved 14 November 2010. - Gorb, Stanislav (2001). "Inter-locking of body parts". Attachment devices of insect cuticle. Springer. p. 305. ISBN 978-0-7923-7153-3. Retrieved 16 November 2010. - Pinhey, E (1962). Hawk Moths of Central and Southern Africa. Longmans Southern Africa, Cape Town.	<urn:uuid:825f8232-2ae3-48b2-86fb-20a02da3266b>	3.546875	696	Knowledge Article	Science & Tech.	64.164179	95,578,543
India-Based Neutrino Observatory (INO) The deep underground laboratory at Kolar Gold Fields (KGF) in India started in 1951. During the subsequent few decades a series of experiments were conducted at KGF to measure the flux of muons as a function of depth up to a depth of 2.7 km. The first atmospheric neutrino interaction ever was observed at KGF in 1965. This laboratory later also looked for nucleon decay and placed limits on the proton lifetime. The KGF underground laboratory ceased its operation in 1992 due to the closure of the mine. The India-based Neutrino Observatory (INO) project is a recent initiative to revive the underground laboratory activities in India. The plan is to construct a new underground laboratory complex under a mountain with at least 1000m rock coverage for conducting experiments in the emerging field of neutrino physics. It is expected that over the years, INO will become a full-fledged underground science laboratory hosting experiments that can exploit its special low-background environment and infrastructure.	<urn:uuid:5cc85dd8-226f-44a5-8224-58d2fbb2cf48>	2.96875	211	Knowledge Article	Science & Tech.	33.889837	95,578,546
Choose some complex numbers and mark them by points on a graph. Multiply your numbers by i once, twice, three times, four times, ..., n times? What happens? Make a footprint pattern using only reflections. Triangle ABC has equilateral triangles drawn on its edges. Points P, Q and R are the centres of the equilateral triangles. What can you prove about the triangle PQR? Find out how the quaternion function G(v) = qvq^-1 gives a simple algebraic method for working with rotations in 3-space. The first part of an investigation into how to represent numbers using geometric transformations that ultimately leads us to discover numbers not on the number line. How did the the rotation robot make these patterns? A design is repeated endlessly along a line - rather like a stream of paper coming off a roll. Make a strip that matches itself after rotation, or after reflection What groups of transformations map a regular pentagon to itself? Arrow arithmetic, but with a twist. Points off a rolling wheel make traces. What makes those traces have symmetry? Explore the meaning behind the algebra and geometry of matrices with these 10 individual problems. A security camera, taking pictures each half a second, films a cyclist going by. In the film, the cyclist appears to go forward while the wheels appear to go backwards. Why? There are thirteen axes of rotational symmetry of a unit cube. Describe them all. What is the average length of the parts of the axes of symmetry which lie inside the cube? Introduces the idea of a twizzle to represent number and asks how one can use this representation to add and subtract geometrically. Follow hints using a little coordinate geometry, plane geometry and trig to see how matrices are used to work on transformations of the plane. This problem provides training in visualisation and representation of 3D shapes. You will need to imagine rotating cubes, squashing cubes and even superimposing cubes! Investigate the transfomations of the plane given by the 2 by 2 matrices with entries taking all combinations of values 0. -1 and +1. My train left London between 6 a.m. and 7 a.m. and arrived in Paris between 9 a.m. and 10 a.m. At the start and end of the journey the hands on my watch were in exactly the same positions but the. . . . How can you use twizzles to multiply and divide? Find the shape and symmetries of the two pieces of this cut cube. An environment for exploring the properties of small groups. I noticed this about streamers that have rotation symmetry : if there was one centre of rotation there always seems to be a second centre that also worked. Can you find a design that has only. . . . Charlie likes tablecloths that use as many colours as possible, but insists that his tablecloths have some symmetry. Can you work out how many colours he needs for different tablecloth designs? A gallery of beautiful photos of cast ironwork friezes in Australia with a mathematical discussion of the classification of frieze patterns. Overlaying pentominoes can produce some effective patterns. Why not use LOGO to try out some of the ideas suggested here? Proofs that there are only seven frieze patterns involve complicated group theory. The symmetries of a cylinder provide an easier approach. Prove that the graph of f(x) = x^3 - 6x^2 +9x +1 has rotational symmetry. Do graphs of all cubics have rotational symmetry? Mark a point P inside a closed curve. Is it always possible to find two points that lie on the curve, such that P is the mid point of the line joining these two points? Patterns that repeat in a line are strangely interesting. How many types are there and how do you tell one type from another? What is the volume of the solid formed by rotating this right angled triangle about the hypotenuse? A white cross is placed symmetrically in a red disc with the central square of side length sqrt 2 and the arms of the cross of length 1 unit. What is the area of the disc still showing? The coke machine in college takes 50 pence pieces. It also takes a certain foreign coin of traditional design... Put your visualisation skills to the test by seeing which of these molecules can be rotated onto each other.	<urn:uuid:9b8d8c9b-147e-4f09-94d7-ad390b12d03e>	3.875	936	Content Listing	Science & Tech.	60.2001	95,578,560
Sometimes called the fourth state of matter, plasma consists of ionized gas wherein one or more electrons aren't bound to a molecule or atom. You may never observe such an exotic substance, but you encounter solids, liquids and gases daily. Many factors affect which of these states matter exists in. Intermolecular Forces at Work Atoms, matter's basic building blocks, combine to create molecules such as water. Intermolecular forces (IMF) between molecules help determine a substance's phase. When the IMF is weak, a substance is usually a gas when the atmospheric pressure is 1 atm (a unit of standard atmospheric pressure) and the temperature is 25 degrees Celsius (77 Fahrenheit). Conversely, the substance will probably be a solid at that same pressure and temperature when the IMF is strong. Solids, Liquids, Gases and Particles Different phases of matter behave in unique ways. In a solid, attraction between particles is greater than their energy of motion -- particles are also close. Particles in liquids are close but their energy of motion and attraction are about the same. Finally, gas particles are far apart and their energy of attraction is less than their energy of motion. Temperature, pressure and a substance's composition affect the way it changes phases. A phase diagram shows the phases that different substances assume at various temperatures and pressures. Vaporization, condensation, sublimation, deposition, freezing, and melting are some of the ways phase changes occur. Vaporization happens when liquid turns to gas, while condensation describes the process in which gas turns back into liquid. When water evaporates, vaporization occurs, and water vapor can return to the liquid state by condensing. Some substances, such as solid carbon dioxide (dry ice) can pass directly from the solid state to the gas state -- scientists call this sublimation. Deposition is the opposite process -- a gas bypasses the liquid state and changes into a solid. Freezing is changing from liquid to solid, and melting is changing from solid to liquid. A substance may transition from liquid to gas by boiling, from liquid to solid by freezing, and from solid to liquid by melting. Ice, liquid water and water vapor may consist of the same molecules, but they differ in several important ways. For example, it's difficult to compress a solid or liquid to a large degree, but you can easily compress a gas. Liquids and gases assume the shape of their containers, but solids do not. Gases have an additional ability to expand when they assume a container's shape and match the container's volume.	<urn:uuid:8671399c-a86e-460a-b386-7ef22ac1360c>	3.84375	527	Knowledge Article	Science & Tech.	36.182924	95,578,561
The majority of the Earth’s terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming1,2,3,4. Despite evidence that warming enhances carbon fluxes to and from the soil5,6, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12–17 per cent of the expected anthropogenic emissions over this period7,8. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon–climate feedback that could accelerate climate change. Access optionsAccess options Rent or Buy article Get time limited or full article access on ReadCube. All prices are NET prices. Subscribe to Journal Get full journal access for 1 year only $3.90 per issue All prices are NET prices. VAT will be added later in the checkout. We would like to thank the Global Soil Biodiversity Initiative (GSBI) for support during this project. This project was largely funded by grants to T.W.C. from Marie Skłodowska-Curie actions, the British Ecological Society and the Yale Climate and Energy Institute. M.A.B. and W.R.W. were supported by grants from the US National Science Foundation and W.R.W. from the US Department of Energy and K.E.O.T.-B. by the Linus Pauling Distinguished Postdoctoral Fellowship programme. The experiments that produced the data were funded by grants too numerous to list here. Extended data figures This file contains Supplementary Text and Data, Supplementary Figures and Supplementary Tables - see contents page for details.	<urn:uuid:cbf1835a-2afc-47da-8a89-992e3a883b45>	2.828125	579	Truncated	Science & Tech.	46.682071	95,578,585
Its not often that amateurs can provide an important support to professional astronomers involved in an international space mission. At a recent comet conference for the forthcoming Rosetta mission, which will orbit comet 67P/Churyumov–Gerasimenko in 2014, and place a lander on the surface. 2011 FR143 was discovered by the Mt.Lemmon Sky Survey (part of the Catalina Sky Survey) on 2011 Mar. 29 and followed until Apr. 26. Its orbit was quite unusual (a=6.83 AU, e= 0.45 and a period of 17.9 yrs) and with a Tisserand parameter of 2.73 it was put in our special list of the T3 observing project. CBET 3069 and M.P.E.C. 2012-F87, issued on 2012, March 25, announced the discovery of a periodic comet by A. R. Gibbs on Mar. 22.8, through the Mount Lemmon 1.5-m reflector. On his images, Gibbs, found a stellar coma and a long, narrow tail about 7.4 arcmin long in p.a. 292.5 deg. The new object has been designated P/2012 F5 (GIBBS) by the Minor Planet Center. Cbet Circular No. 3065, issued on 2012, March 22, announces the recovery of comet P/2005 JY126 = P/2012 F4 (CATALINA) by our team; this comet was discovered on 2005, June 7.32 by Catalina Sky Survey and it was last observed on 2007, January 13. The newly discovered Comet SWAN has now entered the LASCO C2 instrument field on the SOHO spacecraft. This field observes closer to the Sun than the C3 instrument. A few days ago Vladimir Bezugly noted a new comet in images taken with the SWAN instrument on the Solar and Heliospheric Observatory (SOHO) satellite. The comet was located within 20 degrees of the Sun and appeared to be on a Kreutz sungrazing orbit that will take it within a few solar radii of the Sun’s surface. Unfortunately no ground-based observations were possible. This unusual minor planet was discovered by the Spacewatch sky survey on 2011, Dec. 26. It moves along a very eccentric orbit (perihelion close to Mars, aphelion nearly 3 AU away from Saturn). Currently its about 1 AU from Earth and 2 AU from the Sun, approaching its perihelion, scheduled for the end of April 2012 (q= 1.7 AU). Cbet nr. 3021, issued on 2012, February 16, announces the discovery of a new comet (discovery magnitude 21.6) by Larry Denneau and Richard Wainscoat in four exposures taken with the 1.8-m Pan-STARRS 1 telescope at Haleakala on February 15.3. The new comet has been designated P/2012 C3 (PANSTARRS). Cbet nr. 3019, issued on 2012, February 12, announces the discovery of a new comet (discovery magnitude 15.3) by Manfred Bruenjes on 30-s CCD exposures taken on two nights with a 0.36-m f/2.0 Schmidt-Cassegrain reflector on February 11.1 & 12.08. The new comet has been designated C/2012 C2 (BRUENJES). Cbet nr.3016, issued on 2012, February 11, announces the discovery of a new comet (discovery magnitude 18.8) by R. H. McNaught on CCD images obtained on February 5.5, 2012 taken with the 0.5-m Uppsala Schmidt telescope at Siding Spring. The new comet has been designated C/2012 C1 (McNAUGHT).	<urn:uuid:fd1b21db-9b15-4960-8920-093bb9788d99>	2.625	809	Content Listing	Science & Tech.	81.390604	95,578,612
Baro-electric effect and celestial magnetism The nature of the terrestrial magnetism has been creating a problem in geophysics. This book is devoted to the elaboration of the Sutherland hypothesis of the phenomenon proposed in 1903 and almost forgotten now. He supposed the electric charge redistribution in a celestial body under the action of inhomogeneous mechanical stresses (reaction against gravity) and the magnetic field moment resulted from the axial rotation of the charged body. In this book the effect is estimated quantitatively from the quantum theory point of view among others. To describe the magnetic field, generated because of the axial rotation of electrically charged object, electrodynamics of slowly rotating observer is developed. Presented are the estimates of planetary electric and magnetic fields created due to both its internal self-gravitation and external tidal influences. The contribution of the effect into the main geomagnetic field is estimated as approximately 10%. The contribution into the magnetic moments of giant planets is larger. Also considered are other possible geophysical manifestations of the effect including specific properties of the fair weather electricity and possible earthquake forerunners. This book could be recommended not only to Ph.D. students, university faculty members, and researchers, but also to everyone interested in the application of scientific results.	<urn:uuid:70962c8a-3d08-4229-9418-31a375a97dbd>	2.609375	256	Product Page	Science & Tech.	14.635357	95,578,634
How do you use the "round" command? The 'round' expression? It just rounds a floating point number to the nearest whole number. Eg. round(0.7) = 1, round(6.3) = 6. It was missing from System Expressions on the wiki, so I added it. oh... I thought it could be used for grids. Like round 29 to closest 32. You can also use it for that, to round x to the nearest multiple of 32 is something like: round(x / 32) * 32 If the alignment is wrong try floor(x / 32) * 32. Develop games in your browser. Powerful, performant & highly capable. Ok thanks! Since mmf didn't use decimals i was used to do just X/32*32. It's worth noting that division defaults to floating point calculation in Construct - you have to explicitly use Round or Int to specify integer operations (which is opposite to MMF where you explicitly specify when you want to use float operations). You do not have permission to view this topic	<urn:uuid:f674cb47-f38e-4912-abdd-de85cb02cf09>	3.171875	228	Q&A Forum	Software Dev.	83.549549	95,578,640
"Our test wind screen set up on the Rhône glacier resulted in a definite cooling of the air near the surface, with the drop in temperature being up to three degrees centigrade," reported Professor Hans-Joachim Fuchs of the Institute of Geography of the Johannes Gutenberg University Mainz. "We also suspect that this could make it possible to slow down the melting rate of the ice. However, although we were able to observe this phenomenon, we are unable to offer any clear proof of it.” Together with 27 geography students, Professor Fuchs on Friday night presented the results of a project study during which the participants investigated the effects of global climate change on the Rhône glacier and developed solutions to this problem. For this purpose, the students spent 10 days in the Wallis region in August 2008 and set up a wind screen with a length of 15 meters and a height of three meters. Over a period of six days, eleven digital measuring stations were used to record 95,000 measurement values to determine the air temperature directly at the wind screen, in its immediate vicinity, and at a distance from it. The data evaluation showed that the cooling effect was greatest when the sky was clear and there was a prevailing downwind. The temperatures within the wind screen were on average 1.5 to 2 degrees lower at night than the temperatures outside the wind screen. The maximum temperature difference recorded was as much as 3 degrees centigrade. "The further away the stations were from the wind screen, the higher the temperature measured," Fuchs reported. "This is a very definite, well-defined and above all consistent trend, which shows that the wind screen experiment worked." Even on days with low pressure weather conditions, characterized by strong cloud cover and rain, with the wind coming from the south-west, the night-time temperatures inside the wind screen were 0.8 to 1 degree centigrade lower than outside the wind screen. Although the temperatures inside the wind screen area were generally lower during the day, the effect was not as clear as it was at night, as other influences such as direct solar radiation had an effect on the measuring stations. "The effectiveness of the wind screen would surely have been even greater if we had had stable high-pressure weather conditions with stronger, catabatic glacier winds," Fuchs added. For technical reasons, it was not possible to measure the temperature of the ice surface with special infrared devices. Consequently, no data about the cooling of the glacier ice is available. "We were able to observe, though, that the hardness of the ice in the vicinity of the wind screen remained approximately the same throughout the day, while outside the wind screen, the ice crystals melted on the surface and the hardness decreased." Further observations of the project team support the estimate that the melting rate decreased in the vicinity of the wind screen. A survey among visitors to the Rhône glacier also formed part of the project study. Although it was concluded that most of the 230 respondents were aware of climate change, they had no knowledge about the possible consequences and dangers. Against this background, the team designed a learning path called "Seeing and understanding the glacier", which runs along a kilometer-long footpath to a famous ice grotto. The grotto is visited by up to 1,500 tourists per day during the summer months. In addition, a folder was designed to inform people about the glacier, the way it is changing as well as the possible effects of climate change. Both the learning path and the folder were financed by a Swiss company. Another sub-project was the educational film produced by the students of Mainz university using professional equipment, which is to be shown to the public on 6 February 2009. "The test wind screen is, of course, much too small for a glacier. However, as it showed a clear cooling effect, this provides a starting point for further ideas and improvements to the construction. The students have already submitted recommendations in this regard." Project manager Fuchs also pointed out that this is merely a matter of treating the symptoms, while treating the cause remains the "top priority." According to Professor Fuchs, however, the glacier is retreating too quickly to wait until there is global insight into climate protection. "Most of our drinking water reserves are still bound in the glacier ice, but how long will this still be the case?" Prof Dr Hans-Joachim Fuchs \| alfa Global study of world's beaches shows threat to protected areas 19.07.2018 \| NASA/Goddard Space Flight Center NSF-supported researchers to present new results on hurricanes and other extreme events 19.07.2018 \| National Science Foundation A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses... For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth. To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength... For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications. Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar... Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction. A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical... Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy. "Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy.... 13.07.2018 \| Event News 12.07.2018 \| Event News 03.07.2018 \| Event News 20.07.2018 \| Power and Electrical Engineering 20.07.2018 \| Information Technology 20.07.2018 \| Materials Sciences	<urn:uuid:1749fb94-eaf7-488e-82bb-9f1eb99a06c7>	4.0625	1,470	Content Listing	Science & Tech.	43.904029	95,578,658