A dead gray whale washed up on a beach in Alameda on Saturday night, becoming the first reported whale death in the San Francisco Bay Area this year.
The California Academy of Sciences initially reported the whale floating off the coast of Robert W. Crown Memorial State Beach, according to a statement shared by the Marine Mammal Center. The whale may have been stuck in mud or a sandbar, but by early Sunday morning the corpse had dislodged and was floating freely with the tide.
The whale is an adult female gray whale estimated to be about 40 feet long. Academy staffers were able to get close enough via boat for observation and collected blubber samples and measurements, which could be used in case the whale disappeared before it can be moved, said Moe Flannery, ornithology and mammalogy senior collection manager at California Academy of Sciences.
The whale is not the same animal that was entangled in a gill net off the coast of San Francisco two weeks ago, according to the Marine Mammal Center.
The mammal will be towed to waters off Angel Island State Park for a necropsy, which will attempt to determine a cause of death, according to Marine Mammal Center statement. The towing was tentatively planned for Monday.
Some dead whale necropsies can be done at the site where the whale is found, which is “typically a better option” because towing the whale becomes difficult and costly, Flannery said. But because the gray whale was floating near a popular beach and was near mud flats that were unsafe to walk on, the situation was “more complicated,” she added.
The U.S. Coast Guard was aware of the whale and towing effort but was not involved in the operation, said U.S. Coast Guard Petty Officer Hunter Schnabel.
The National Oceanic and Atmospheric Administration declared an Unusual Mortality Event for gray whales in 2019 due to a larger-than-usual number of dead whales in poor condition washing ashore along their migration range. The UME has since closed, according to the Marine Mammal Center statement.
“Climate change is affecting the food that the whales are able to get in the Arctic, so they were not gaining enough weight in the summer feeding grounds to make their long migration down to Mexico and back up to the Arctic,” Flannery said.
Despite the death, researchers can take it as a positive sign that this is the first dead gray whale that has washed up in the San Francisco Bay Area this year, Flannery explained.
“Hopefully we will start to see the population recover,” Flannery said. It will likely take around a decade for the population to return to its pre-UME levels, he added.
Research from the Marine Mammal Center and Cal Academy has identified malnutrition, entanglement and vessel strike trauma to be the leading causes of death for gray whales in recent years. Other factors in deaths include infectious diseases, natural predation, harmful algae blooms and human interactions.
