Death In The Bay: Five More Gray Whales Wash Up Along San Francisco Coastline

Five gray whales have died in the San Francisco Bay Area region in the past week or so, bringing that unfortunate number to more than a dozen this year, the California Academy of Sciences said Wednesday. The causes of death for all five whales have yet to be determined by the San Francisco-based Academy of Sciences and its partners at the Marin Headlands-based Marine Mammal Center. Two whales died Monday: a gray whale near Alcatraz Island and a gray whale at Point Bonita in Marin County.

Last Thursday, two gray whales also died: a subadult female near Berkeley and a whale in Fisherman’s Bay on Southeast Farallon Island off the San Francisco coast. On May 21, a yearling gray whale was found dead in Bolinas in Marin County. Wildlife officials said necropsy response efforts and data collection have been challenging due to the inaccessible locations of the whales, poor tissue quality from advanced decomposition, and the lack of available locations to tow for further investigation. So far in 2025, 13 gray whales and one minke whale have died in the region. Three of the deaths were caused by likely vessel strikes. Academy of Sciences officials said they haven’t responded to this many dead gray whales in the area since the height of what they call an Unusual Mortality Event in 2019 (14 individuals) and in 2021 (15 individuals).

The Marine Mammal Center’s Cetacean Conservation Biology team said there have been an unusually high number of whale sightings in the San Francisco Bay this year, with 33 individual gray whales confirmed via photo identification (only four gray whales were sighted in the Bay in 2024). Roughly a third of these whales stayed in the Bay for at least 20 days, and their overall body condition ranged from normal to emaciated.

Researchers are still investigating why there has been such a massive spike in sightings this year. They expect gray whales to stay in the year for another week or two before continuing their annual northern migration to arctic feeding grounds. Scientists in Southern California reported record-low calf counts earlier this year, which is a cause for concern, Academy of Sciences officials said. Researchers say it’s vital that all boaters — from large commercial vessels to sailboats — be “whale aware” and continue to slow down. Gray whales often have a very low profile in the water, making them difficult to see. People can report dead, injured or stranded marine mammals in the San Francisco Bay Area by calling the California Academy of Sciences at (415) 379-5381 for dead animals or the Marine Mammal Center at (415) 289-7325 for live animals.