Photo: Marjorie Cox//The Marine Mammal Center
Five more gray whales were found dead in San Francisco Bay area this week. The new deaths are the latest in a string of whale fatalities in the region, which brings the total for 2025 to 14, according to local authorities.
The news comes from the California Academy of Sciences and The Marine Mammal Center, that published a joint press release Wednesday, confirming the deaths. All were gray whales, found between May 21 and May 26.
The causes of death are still undetermined, due to difficulty in performing post-mortem examinations of the remains. “Necropsy response efforts and data collection have been challenging for a number of cases due to inaccessible locations that hinder full post-mortem investigations, as well as poor tissue quality from advanced decomposition, and the lack of available locations to tow for further investigation,” noted the release.
Even more troubling, the spate of deaths continues an ongoing trend. In total, 13 gray whales and one minke whale have died in the San Francisco Bay region since the start of the year. The last times we saw numbers that high were in 2019 and 2021, when the 2019-2023 Unusual Mortality Event (UME) claimed 14 and 15 whales, respectively.
The deaths have been accompanied by an unusually high amount of whale sightings in the area. Cal Academy reports 33 individual whales confirmed – a stark contrast to only four in 2024. The reason behind both the increased whale sightings and accompanying deaths is still being investigated, but the animals are expected to spend another week or two in the area, before migrating north to arctic feeding grounds.
