Why are gray whales dying in San Francisco's waters? US scientists search for clues

Experts suggest the San Francisco Bay area offers a rare opportunity to study migratory shifts and changes in foraging due to climate change; with protections, the bay could become a new foraging stopover aiding the gray whales' migration and recovery.

The Coast Guard and ferry companies implemented safety measures and training to give whales space, slow down, and call sightings; officials also planned to install an infrared camera on Angel Island to monitor surface activity at night in high-traffic areas.

Researchers noted very low calf counts, signaling a low birth rate; this, combined with a high rate of human-caused mortality in the area, raises concerns about the population's ability to recover.

Researchers reported a second whale needed immediate attention after the first, and there was no place to hold the first whale, causing the second to float out of the bay.

An approximately 30-40 tonne gray whale began floating in the bay and was towed by the Army Corps of Engineers to a secluded beach for a necropsy; before the first necropsy could be completed, researchers were called to attend a second whale needing immediate attention, and it floated out of the bay.

Slaathaug's study examining hundreds of photographs and carcasses from 2018 onward was published in Frontiers in Marine Science this week, describing a high rate of death in San Francisco Bay and whales' vulnerability to vessel strikes.

Two gray whales were sighted in San Francisco Bay in January 2026, indicating the season began earlier than the usual peak in April.

In 2025, a record total of 21 Eastern North Pacific gray whales were found dead in the broader San Francisco Bay, signaling a period of elevated mortality in the region.