The whale was found on Ocean Beach and reported to the Marine Mammal Center at 6:30 a.m. Monday, the San Francisco Chronicle reported. Scientists at the center will conduct a necropsy Tuesday to determine the cause of death.
“The death of nine gray whales in the San Francisco Bay Area this year is a cause for serious concern and reinforces the need to continue to perform and share the results of these type of investigations with key decision-makers,” the center’s lead research pathologist Dr. Padraig Duignan said in a statement.
1/2: The Marine Mammal Center confirms a dead gray whale washed ashore early this morning at Ocean Beach in San Francisco. Our scientists & partners plan to perform a necropsy, or animal autopsy, tomorrow in an attempt to determine the cause of death. 📸 Credit Sarah Maria Curran pic.twitter.com/6sDhSnhz8H— The Marine Mammal Center (@TMMC) May 6, 2019
The scientists do not yet know the age, sex or length of the whale found Monday. Eight other gray whales have washed up in the Bay Area in the past two months: three of them died after collisions with ships and four died of malnutrition, the center has concluded so far.
“Their skeleton seems to stick out more and more,” Duignan told the told the Los Angeles Times earlier this month of the whales that died of starvation.
Duignan said that the center usually sees only two or three dead gray whales a year. But the problem isn’t limited to the Bay Area. More gray whales this year appear to be suffering from malnutrition as they migrate up the Pacific Coast from Mexico to the Arctic. Thirty-one dead whales have been found along the entire Pacific Coast, 21 in all of California. Living whales show signs of poor nutrition, and there are markedly fewer mother and calf pairs, the Los Angeles Times reported.
This year has seen the most dead gray whales for this time of year since 2000, when 86 died. University of California Davis School of Veterinary Medicine research associate Frances Gulland told the Los Angeles Times that the number could rise to 60 or 70 by the end of the migration period.
“If this continues at this pace through May, we would be alarmed,” she said.
Scientists don’t yet know why the whales appear to be suffering more this year. In addition to the deaths, marine biologist Steven Swartz said 23 percent of the whales he had observed without calves were skinny, more than three times the normal number. However, other species of whale have not been impacted.
Researchers think the gray whales did not get enough to eat while feeding in the Arctic last summer, and NOAA’s Alaska Fisheries Science Center plans to study the whales’ Arctic feeding habits to better understand what might be happening.
One hypothesis is that the loss of sea ice might have rendered prey more scarce. Another possibility is that a marine heat wave discovered off the Gulf of Alaska in 2013 might have impacted the surrounding ecosystem.
Gray whales were removed from the endangered species list in 1994 after an international agreement to stop hunting the 90,000 pound creatures in 1946 helped their population to recover, CNN explained. There are now around 27,000 gray whales in the world, so this year’s deaths do not threaten the species on a population level. But Duignan told the Los Angeles Times that it’s important to understand any changes with the whales. “We are concerned because whales are an indicator species for the health of the ocean,” he said. “We use them to tell us what’s happening out there.”
Washington state biologist John Calambokidis agreed.
“It’s not like we’re ringing the alarm bell that this population is threatened or at risk,” he said. “As a researcher, I feel that you want to at least understand what is going on.”