Dead fish wash ashore as toxic red tide hits the San Francisco Bay Area

At least 21 marine animals have washed ashore dead throughout the San Francisco Bay Area in the last week — potential victims of the return of the same toxic red tide that killed thousands of fish in the region last year.

Harmful algae blooms of this kind can be caused by a number of different microorganisms, but this red tide is associated with one called Heterosigma akashiwo, which was also the culprit behind last year’s event, said Ian Wren, an algae expert and staff scientist for San Francisco Baykeeper.