Either industrial toxic discharge or Red tide phenomena?
Red tide is a common name for
algal blooms, which are large concentrations of aquatic
microorganisms, such as
protozoans and
unicellular algae (e.g.
dinoflagellates and
diatoms).[
citation needed] The
upwelling of nutrients from the
sea floor, often following massive storms, provides for the algae and triggers bloom events. Harmful algal blooms can occur worldwide, and natural cycles can vary regionally.
[1]
Red tide in a harbor,
Japan
The growth and persistence of an algal bloom depends on wind direction and strength, temperature, nutrients, and
salinity.
[1] Red tide species can be found in oceans, bays, and
estuaries, but they cannot thrive in
freshwater environments.
[2][1] Certain species of
phytoplankton and dinoflagellates like
Gonyaulax found in red tides contain
photosynthetic pigments that vary in color from brown to red. These organisms undergo such rapid multiplication that they make the sea appear red. When the algae are present in high concentrations, the water may appear to be discolored or
murky. The most conspicuous effects of red tides are the associated wildlife mortalities and harmful human exposure. The production of natural
toxins such as
brevetoxins and
ichthyotoxins are harmful to
marine life.
[3] Effects of red tides can worsen locally due to wind driven
Langmuir circulation and their
biological effects.
