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Why Are So Many Gray Whales Showing Up On The Shores Of The Bay Area?

Hey Area is where we find answers to questions you ask. Listener Harry Tarpey wanted to know Why are so many whales washing up dead around the Bay Area?

Walking along Bay Area beaches, you expect to see beautiful open water, seagulls, families soaking in the sun and not a 90,000 pound gray whale carcass. 

“Whales are suspended in water. Their bodies aren't used to being on land,” says Dr. Shawn Johnson. 

“So they get flattened as they start to decompose, their skin starts to slough and, it turns a white and that's they're brown or dark skin coming off.” He’s the Director of Veterinary Science at the Marine Mammal Center (MMC) of Sausalito where they’ve been busy researching the gray whales' deaths. 

In a normal year, the number of dead gray whales they find in the Bay Area is anywhere from zero to four. This year it’s thirteen. That’s enough for the National Oceanic and Atmospheric Administration to declare an Unusual Mortality Event (UME) and cause for investigation. Numbers of dead gray whales haven’t been this high in 20 years. 

The Marine Mammal Center has been on the scene investigating 12 of the 13 dead gray whales to wash up on the San Francisco Bay. 

“We do a full necropsy or in human medicine is called autopsy. And that allows us to determine the cause of death and often why they stranded in the first place,” explains Johnson.

This year between Mexico to Alaska almost 200 gray whales have stranded. During necropsies, marine biologists are finding seaweed and even plastic in the whales’ bellies in contrast with their normal diet of seafloor invertebrates. 

“Basically they were starving to death,” says Johnson.

Gray whales usually only eat in Alaska before migrating to the warmer waters of Baja California Mexico to spawn in the winter. Recently the whales are underfed before they leave Alaska which causes the whales’ starvation during their northern migration. Mother whales and their nursing calves are especially susceptible to starvation. The emaciated whales stray from their migration patterns looking for food in unlikely places

“Some of them also got hit by ships coming into the bay where they normally don't go and getting into the path of these cargo ships that come into our bay,” says Johnson

Johnson says they may be able to use information from necropsies. The Marine Mammal Center works with the government organization National Oceanic and Atmospheric Association (NOAA) to share information and make policy recommendations around the spike in gray whale deaths.

“If we know that this is going to happen next spring, maybe we can put in some more regulations or recommendations to the shipping industry to help maybe prevent some of the ship strikes that happened this season.

If you’re concerned about these whales, the Marine Mammal Center says here’s actually something you can do 

“You could be hiking in a really remote beach in Point Reyes and find a dead whale on the beach. And, and you might be the very first person have seen that whale on the beats...So taking photographs of it. Getting, uh, an estimation of how long it is and, and then calling us here at the Marine Mammal Center.”

That way they can get to the whale quickly and learn as much as possible. 

To report a stranded marine mammal: Call (415) 289-SEAL or email rescue@tmmc.org (photos are especially helpful).