Datasets:
patrickbdevaney
/
mia9

Dataset card Data Studio Files
xet
 Community
1
text
stringlengths
0
6.44k
than optimum freshwater inflows, at least during dry periods.
The relationships between salinity and environmental responses must be
examined to understand how freshwater discharges and salinity variations affect
Introduction
Freshwater Flow and Ecological Relationships in Biscayne Bay 1-4
the plants and animals that inhabit the system. Therefore the initial focus of the
MFL development efforts is on identifying the important species (e.g., popular
gamefish, economically valuable species, endangered species) and indicator
species and their food sources, which normally use areas of reduced salinity
during all or part of their life cycle.
MFL WORK IN OTHER FLORIDA ESTUARINE SYSTEMS
Previous efforts to establish minimum flows and levels in estuarine waters in
Florida that have produced written documentation are summarized in Table 1.
Most of these reports are recent, and many are not complete. As noted by Estevez
(2000), "very few published or unpublished accounts exist to inform the
establishment of minimum flows in highly altered riverine estuaries, especially
when honoring the additional constraint that such minimum flow methods rely
primarily on living resources." That has not changed much since his work, but
general direction is being given with the pioneering work in the Loxahatchee, St.
Lucie, Caloosahatchee and St. Johns Rivers and their associated estuaries.
Lagoonal ecosystems, such as Biscayne Bay, are still basically unstudied with
regard to the best approach to establishing MFLs. This discussion was further
revised and published in 2002 (Estevez 2002).
Flannery and Peebles (2002) report that in examining indicators for MFL
establishment in the west coast of Florida, “best professional judgment”
combined with good fisheries science has resulted in the preliminary
determination that a “maximum percentage removal” standard is the best
approach for those riverine estuaries.
When an estuary has a very low level of anthropogenic impacts, establishment of
MFLs may look at the pre-development conditions for the estuary and watershed
and determine if it is possible to restore some or all of the pre-development
estuarine functions. Given the level of development in all the watersheds in
Florida, this is not a common approach. Mattson (2002), however, describes the
approach to the management of freshwater flows in the Suwannee River estuary
and characterizes the approach as a "natural flow regime principle" which
assumes that an altered hydrologic regime (i.e., the MFL) "...is still near-natural
in terms of magnitude, frequency, duration and timing of freshwater inflows..."
Table 1
Other MFLs Projects in Estuarine Waters in Florida
Water Body WMD
Status and
Date Summary of MFL Indicators MFL Target Source
Northwest
Fork of the
Loxahatchee
River
SFWMD Final Draft
Nov 2002
Prevent flows into the NW Fork
less than 35 cfs for more than 20
days more than once every six
years
Vegetation: Presence/absence of six
freshwater swamp tree species (other
than cypress)
Recovery
(i.e., currently significant
harm is occurring)
SFWMD
2002a. b. c
St. Lucie
River and
Estuary
SFWMD Final Draft
May 2002
Sufficient flows to prevent loss of
oligohaline habitat (0.5 to 5.0 psu)
in the estuary for two successive
months during the dry season,
during two years in a row
Salinity Regime: Maintain
oligohaline zone as a VEC with ongoing work to characterize responses
of benthic plants and oysters to rapid
changes in salinity and identify
specific species of VEC's as indicators
Prevent Significant Harm
(i.e., - currently
significant harm is not
occurring
SFWMD
2002d, e
Lake
Okeechobee,
the Everglades
and Biscayne
Aquifer
SFWMD Draft
Feb 2000
Only the Everglades has an
estuarine component. Sufficient
flows are designated to maintain
desired salinities in coastal
estuaries
Soils: Meet limits on low water levels
and duration to maintain appropriate
conditions in the two dominant soil
types in freshwater portions of the
ecosystem
Recovery
(i.e., Currently significant