Starving gray whales turning up in extraordinary numbers

05/16/2019

Gray whales are travelers, migrating the farthest of any other whale species, from Alaska to Baja and back again every year, but this spring California proved a dead end for some. Ten gray whales have washed up since March, primarily in and around the San Francisco Bay. The Marine Mammal Center, the first responder for marine mammals across 600 miles of California coastline, attributed half of the deaths to ship strikes and the other half to malnutrition, based on necropsies. The journey that gray whales make every year from Alaska, where they feed, to Baja, where they breed, is roughly 11,000 miles. They are the most frequently sighted whales in California, passing by the state during their southern migration in winter and again in April and May as they return north. “What we saw this year was that there appeared to be very little food in their customary feeding areas in the Arctic: they don’t have sufficient reserves,” Mary Jane Schramm, a spokeswoman for the Greater Farallones National Marine Sanctuary, told the Light. As a result, more whales are stopping in the San Francisco Bay. Bill Keener, a whale expert at Golden Gate Cetacean Research, explained in a recent press release that he thinks the whales are looking for food or seeking shelter, given their weakened state. Compared to the typical one or two passing underneath the Golden Gate Bridge—a dangerous shipping route for whales—each season, Mr. Keener’s team has seen as many as five a week at several points this spring. “We’ve seen them foraging in the San Francisco Bay, but what they are finding is a subject of concern,” Ms. Schramm added. “The bay has a history of industry and is certainly not the clean environment they would ordinarily find in the Arctic.” The year is exceptional: this spring brings the total number of gray whales to which the Marine Mammal Center has responded during its 44-year history to 80. Late last month, a gray whale washed up on Limantour Beach. Though there was evidence of both malnutrition and impact with a ship, a spokesman from the Marine Mammal Center, Giancarlo Rulli, said the cause of death is pending further investigation: it isn’t clear if the whale was already dead when it was hit. Three deaths occurred in San Francisco, two in Pacifica, and four others in Richmond, San Mateo, Hercules and Rodeo. The center released a steady stream of press memos over the past two months documenting the deaths, drawing the link between malnutrition and anomalous oceanographic conditions. Insufficient layers of ice in the Arctic—which create the habitat for the algae that in turn feeds the bottom organisms the grays typically consume—is a possible contributing factor, Ms. Schramm said. Once common throughout the Northern Hemisphere, gray whales are now only found in the North Pacific, where there are two populations. The eastern population was listed as endangered until 1994; the western population remains very low, at around 200 individuals, and is listed as both endangered and depleted. Speaking on behalf of the sanctuary, which has helped implement voluntary slow-downs for ships, Ms. Schramm said: “Many of the gray whales traveling through the relative safety of our outer coast waters of the sanctuary are detouring into the dire straits of San Francisco Bay in an act of desperation. Anyone on boats and other watercraft should prevent additional stress by staying at least 300 feet away and give them every break you possibly can.”