We've been seeing another spike in gray whale mortality this year around the Bay Area that isn't well explained, but an unusual number of gray whales have been entering and hanging out in SF Bay this spring.
Over the past week, five more dead gray whales have turned up around the Bay, bringing the recent local death toll to 14. As KRON4 reports, the first in this recent group was a dead yearling found in Bolinas on May 21. The following day, May 22, a female gray whale was found dead in the Bay near the Berkeley Marina, and another whale death was recorded at Southeast Farallon Island.
On Memorial Day, May 26, two more dead whales were found at Point Bonita and on Alcatraz Island.
Officials with the Marine Mammal Center and California Academy of Sciences say that the causes of death for these most recently found whales likely won't be determined due to advanced decomposition and complications around performing post-mortem examinations.
Several whale deaths that have occurred around the Bay earlier this year have been attributed to boat strikes, and malnutrition may be a factor as well. Eight previous whale deaths have been recorded since this year's northern migration began, seven of those being gray whales. A rare Minke whale showed up in the Bay appearing ill, and had to be euthanized in early April after beaching in Emeryville.
The Academy of Sciences notes that 33 individual gray whales have been spotted in San Francisco Bay so far this year, up from just four last year. And at least 10 of these whales have gone on to spend 20 or more days in the Bay.
Local whale experts say this is the largest number of gray whale deaths in the region since 2021, when 15 were recorded, and the larger North Pacific gray whale population appeared to be in decline. And at this rate, the local gray whale death toll this year is likely to exceed that of 2021.
In 2023, one apparently sick gray whale spent a record two months roaming around San Francisco Bay before ultimately dying.
Officials say that the whale migration should move beyond the Bay Area within a couple of weeks, and gray whale sightings should dissipate.
Reports of humpback whales in the Bay have been fewer the last few migration seasons, but they had been making regular appearances here for several years, likely because schools of anchovies were plentiful in previous seasons.
Gray whales are opportunistic eaters who can find plankton and other food in the Bay, and they may be pausing in their trips north to eat before reaching the ultimately feast in the waters off Alaska. Experts in previous years have noted gray whales arriving in the Bay looking emaciated, and some sightings this year have been of skinny whales as well, according to the Cal Academy.
Top image: Photo by Kate High/California Academy of Sciences
