Officials with the San Francisco Bay Regional Water Quality Control Board said that harmful algal blooms also known as “red tides” found recently in parts of the Bay have not so far brought widespread fish deaths like a similar event in the region last year.

The water board and other agencies have been monitoring the algal blooms seen since early this month along parts of the shoreline in areas off of Alameda, between Emeryville to Albany, and certain parts of Marin County, but have not found any significant harm to aquatic life.

However, the water board is advising people and their pets to avoid swimming or otherwise coming in contact with discolored water in the Bay until further notice.

An Oakland Public Works crew removes dead fish from Lake Merritt on Aug. 31, 2022, during a red tide outbreak. A similar harmful algal bloom this month has not resulted in mass die-offs of fish. (City of Oakland via Bay City News)

The water board has issued a list of frequently asked questions about the algal bloom that can be found its website.

Last summer, a red tide in the Bay led to large quantities of fish deaths attributed to depleted oxygen in the vicinity of the algal blooms, though the water board notes that red tides are relatively common and are known to occur off of California’s coast or come into San Francisco Bay.

Anyone who spots a suspected harmful algal bloom can fill out an online form or send an email or call 844-729-6466.

Reports of dead fish can be sent to the SF Bay Harmful Algae Bloom 2023 project on iNaturalist, set up by the California Department of Fish and Wildlife.

Dan McMenamin is the managing editor at Bay City News, directing daily news coverage of the 12-county greater Bay Area. He has worked for BCN since 2008 and has been managing editor since 2014 after previously serving as BCN’s San Francisco bureau reporter. A UC Davis graduate, he came to BCN after working for a newspaper and nonprofit in the Davis area. He handles staffing, including coaching of our interns, day-to-day coverage decisions and management of the newswire.