4 gray whales found dead in San Francisco Bay Area in past week
Four dead gray whales have washed ashore in the Bay Area in the past week, prompting concern among scientists about the length and intensity of a die-off of the giant mammals that is now in its third year, the San Francisco Chronicle reported.
The first whale carcass landed at San Francisco’s Crissy Field on March 31. Another was found in the Fitzgerald Marine Reserve at Moss Beach on Saturday. A third found floating in the bay was towed Wednesday to Angel Island, where staff from the Marine Mammal Center in Sausalito were to perform a necropsy Thursday morning when they got a call that a fourth had washed up on Muir Beach.
On Friday, the Marine Mammal Center said a ship strike was the cause of death of the 41-foot adult female found on Muir Beach. Scientists from the center and the California Academy of Sciences found signs of blunt-force trauma — hemorrhaging and bruising around the animal’s jaw and neck — typical of that kind of impact. They have not determined for certain the cause of death for the other animals, though a ship strike is also suspected for the one at Moss Beach. The deaths are part of a pattern seen before in a similar die-off in 1999 and 2000. This one has lasted three years so far.
“Our team hasn’t responded to this number of dead gray whales in such a short span since 2019, when we performed a startling 13 necropsies in the San Francisco Bay Area,” said Dr. Pádraig Duignan, director of pathology at the Marine Mammal Center, in a statement. “Gray whales are ocean sentinels due to their adaptability and foraging habits, meaning they have a lot to tell us about the health of the ocean, so to see the species continue to suffer with the added threats of human interaction is a major cause for concern.”
The necropsy of the gray whale towed to Angel Island found it to be a young 37-foot male that did not show signs of either a ship strike or malnutrition, the two main causes of gray whale deaths since 2019. The same was true for the animal that washed up on Crissy Field, the Marine Mammal Center said.