Alarming number of whale deaths reported around San Francisco Bay Area

Watch: Killer whales attack gray whales

A drone from a whale watch boat caught amazing footage of up to 30 orca whales attacking 2 adult gray whales.

SAN FRANCISCO – An alarming number of gray whale deaths have been reported around the San Francisco Bay Area this year, with six carcasses discovered during the past week alone.

According to staff at the California Academy of Sciences, a research institute and natural history museum based in San Francisco, 15 stranded whales, made up almost entirely of gray whales, have been found dead across the region since the start of 2025.

The figure is the highest since 2021, when what was called an Unusual Mortality Event was underway.

According to NOAA Fisheries, from 2019 to 2023, the population experienced a decline of roughly 45%, which was investigated by biologists.

A research team determined that ecosystem changes in the whales' feeding areas ultimately led to changes in food availability, malnutrition and a decrease in birthing rates.

DUNGENESS CRAB DIE-OFF UNDERWAY ALONG US WEST COAST

An alarming number of gray whale deaths have been reported around the San Francisco Bay Area this year, with six carcasses discovered over the past week alone.

(California Academy of Sciences / FOX Weather)

Marine scientists said it is difficult to determine what is causing the latest surge, with only a few cases tied to vessel strikes.

Staff from The Marine Mammal Center also noted an unusually high number of sightings of live marine animals in San Francisco Bay, with 33 individual gray whales spotted since January.

"By comparison, only six gray whales were sighted in the bay in 2024," staff said. "Roughly one-third of these whales have stayed in the bay for at least 20 days, and their overall body condition has ranged from normal to emaciated. The reason or potential reasons behind the massive spike in sightings this year are still being investigated by researchers. It is expected that gray whales will be in the bay for another one to two weeks before continuing their annual northern migration to arctic feeding grounds," staff stated.

SPECTATORS GATHER AS KILLER WHALE WASHES ASHORE FLORIDA COAST

Researchers in Mexico, Canada and the U.S. are said to be actively monitoring the population and have also reported low calf counts.

The whales will soon feed around the Arctic before making their round trip along the U.S. West Coast back down to the warm waters off Mexico for the winter.

NOAA estimates the population is around 10,000, which is significantly higher than the North Atlantic right whale count, which is estimated to be near 400 individuals.

The North Atlantic right whale species has simultaneously experienced a significant die-off, which has been tied to entanglements or vessel strikes.