Heterosigma akashiwo

Heterosigma akashiwo (Hada) Hada ex Hara et Chichara is a microscopic alga in the class Raphidophyceae.

Description
Heterosigma akashiwo is a swimming marine alga that episodically forms toxic surface aggregations known as a red tide or harmful algal bloom (HAB).

Life cycle
Heterosigma akashiwo produces cysts as a resting stages.

Heterosigma forms massive brown tides that impact the survival of organisms at every trophic level. This alga has been shown to kill finfish, compromise fish and sea urchin egg development and impact copepod as well as oyster survival. The 1997 H. akashiwo bloom in British Columbia, for example, coincided with a dramatic increase in mortality of captive salmon. Moreover, the global distribution of H. akashiwo is increasing as is the frequency of H. akashiwo HAB formation.