 A sharp change in flow velocities can also prevent some motile plankton from orienting themselves or swimming vertically.This fluid mechanism is called gyrotactic trapping.Critical Scales and Thin Layers

Phytoplankton

Zooplankton

Red tide

Karenia brevis

Algal bloom

Dinoflagellate

Halocline

Thermocline

Pycnocline

Chemotaxis