Gray whales are dying at alarming rates in San Francisco Bay, with 18% of those entering the area from 2018 to 2025 not surviving, according to a study in Frontiers in Marine Science. Ship strikes account for at least 40% of confirmed deaths, though experts suggest the true toll could be nearly double, as many carcasses go unrecovered. Researchers like Josephine Slaathaug manually cataloged whale sightings and carcasses, revealing the hidden scale of human-caused fatalities.

The whales’ presence in the Bay is linked to climate-driven food shortages in Arctic feeding grounds. Declining sea ice disrupts phytoplankton blooms, reducing prey for migrating whales. Scientists speculate they may be foraging in the Bay’s muddy depths, a theory supported by observed sediment plumes and stomach contents. This shift brings them into conflict with busy shipping lanes, where container terminals and ferries create lethal overlaps.

Efforts like Whale Safe, which shares whale locations with ship captains, and Blue Whales Blue Skies, promoting slower speeds, aim to reduce collisions. However, current speed limits—some ferries hit 30 knots—remain far above the 10-knot threshold proven to improve survival rates. Without stricter measures, the Bay’s growing whale population risks becoming a casualty zone.

This crisis underscores the urgency of balancing maritime commerce with marine conservation. As climate change reshapes ecosystems, protecting vulnerable species like gray whales demands coordinated action to mitigate human threats.