Necropsy shows gray whale washed up on Bolinas Beach died from ship strike
BOLINAS, Marin County -- The death of a gray whale found on Bolinas Beach last week was most likely caused by blunt force trauma from a vessel, the Marine Mammal Center said Thursday.
In a necropsy of the whale carried out on Saturday, a team of scientists found injuries indicative of blunt force trauma, and "the scale of the trauma is consistent with vessel collision as the cause of death," the Marin Headlands-based center said.
The whale was an otherwise healthy 35-foot subadult male, the center said, and decomposition showed that he probably died two days prior to the examination.
Still, the overall condition of the whale was good news, the center said.
"It was relief to see this young male gray whale in such good body condition with a thick layer of blubber and lots of fat and oil," said Moe Flannery, senior collections manager of ornithology and mammalogy at the California Academy of Sciences. "Although it is the first stranding of the year in the Bay Area, we are hopeful the good body condition is an indicator that the species is doing better now compared to the last few years."
The National Oceanic and Atmospheric Administration (NOAA) has declared an ongoing "unusual mortality event" since 2019 as elevated numbers of gray whales began washing ashore in poor body condition.
According to NOAA, the number of gray whales migrating along the West Coast has dropped 38 percent during this time.
The Marine Mammal Center said the leading causes of death for these animals are malnutrition, entanglements and trauma from vessel strikes.
Gray whales are currently migrating north along the coast from their birthing grounds in Baja California, Mexico up to their traditional feeding grounds in Alaska, the center said.
The center determined that at least four whales died from ship strikes along the coast between April and August of 2022.
