US EditionNearly 1 in 5 Gray Whales Entering San Francisco Bay Die There, Study Finds
Researchers matched 21 photo-identified whales to carcasses and found vessel strikes caused many deaths, underscoring pressure on a population already in decline.
- Researchers reported Monday, April 13, 2026, in Frontiers in Marine Science that nearly 1 in 5 gray whales entering San Francisco Bay die there, highlighting significant risks along their 16,000-kilometer migration route.
- Gray whales migrate between the Arctic and Mexico annually, but since 2018 hungry whales began stopping in the bay to feed as Arctic conditions worsened, coinciding with population declines and increased die-offs in recent years.
- Sonoma State University whale biologist Josephine Slaathaug identified 114 whales visiting the bay between 2018 and 2025 using 100,000 photos; of 70 documented carcasses, 30 deaths were caused by vessel strikes, though scientists believe this underestimates the toll.
- A 42-foot adult female gray whale was found dead near the Golden Gate Bridge on Tuesday, with a necropsy performed at Angel Island on Wednesday indicating injuries consistent with a suspected vessel strike.
- The Marine Mammal Center reported this as the first death in the Bay Area this year, with the population now at 12,900, the lowest since the 1970s. Marine ecologist Joshua Stewart warned desperate whales face a "high chance of not making it back out.
16 Articles
16 Articles
Gray whales are entering San Francisco Bay and many aren’t surviving
Gray whales are beginning to break their long-established migration patterns, venturing into risky new territory like San Francisco Bay as climate change disrupts their Arctic food supply. But this unexpected detour is proving deadly: nearly one in five whales that enter the Bay don’t survive, with many struck by ships in the crowded, foggy waters.
The Conversation
littlebytesnews.comGray whales are dying in San Francisco Bay at an alarming rate – this isn’t normal
Gray whales have unique markings, making it possible to track each one in the bay. Jane Tyska/Digital First Media/East Bay Times via Getty ImagesAt least six gray whales have died in San Francisco Bay from mid-March to early April 2026. These deaths follow a pattern over the past few years, and they are raising concerns among marine biologists like us that 2026 is becoming another dangerous year for a struggling population. The majority of easte…
Of gray whales that enter San Francisco Bay, nearly 18% die there, scientists find
Gray whales migrate from Arctic waters full of food to the lagoons of Baja Mexico—but as the climate crisis gathers pace, they have been sighted foraging in unexpected places. Recently, some have begun to explore the dangerously busy waters of San Francisco Bay. Scientists at the Marine Mammal Center and the California Academy of Sciences investigating an unexpectedly high death toll among gray whales have found that almost 20% of individuals se…
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