---
id: red_tide
type: element
name: Red tide / harmful algal bloom
task_types: [semantic_segmentation, classification]
preferred_heads: [validity, context, semantic_segmentation]
label_formats: [mask, polygon, image_label]
positive_label: red_tide
negative_policy: unlabeled_is_ignore
typical_sensors: [PMS, MUX, MSS, MSI, OLI]
typical_resolutions_m: [10, 30]
---

# Red Tide

Red tide is often a broad water-color anomaly rather than a sharp object. It may
need both local texture/color features and broader context.

## Required Context

- Water background and turbid-water hard negatives are important.
- Clouds, haze, sunglint, and sensor striping should be explicit context or ignored.
- Do not assume external water/land masks.

## Recommended Output

- Pixel-level red-tide probability for segmentation data.
- Scene or patch-level likelihood when only weak labels are available.