Gray Whales Increasingly Entering San Francisco Bay Face High Mortality from Ship Strikes and Malnutrition Amid Climate Change

Tue, 14 Apr 2026 06:09:00 +0200

Gray whales, traditionally known for their long migrations between Arctic feeding grounds and Baja California breeding lagoons, are increasingly venturing into San Francisco Bay as climate change disrupts their primary food sources in the Arctic. Researchers documented 114 individual whales entering the Bay between 2018 and 2025, with many appearing unusually thin and foraging in this unfamiliar, high-traffic area. Nearly one in five of these whales did not survive, according to a study published in Frontiers in Marine Science. Of 70 gray whale deaths recorded in the region during this period, 30 were confirmed vessel strikes, while many others showed signs of malnutrition. Scientists identified 21 of the dead whales as individuals previously cataloged in the Bay using unique skin markings from public sightings and surveys. Only four whales were seen in the Bay in more than one year, suggesting limited repeat use and high mortality risk. San Francisco Bay's foggy conditions and role as