Toxin Produced: no toxin reported
Syndrome: none described; fish kills possibly due to oxygen depletion and bird kills due to production of surfactants.
Akashiwo sanguinea (formerly called Gymnodinium sanguineum or Gymnodinium splendens) can form dense blooms, especially in summer to early fall. It is reported to kill fish and birds. Mortality may be due to clogging of shellfish gills, the production of surfactants, or to oxygen depletion when blooms decay.