Blubber Trouble

Warm water imperils young sea lions

It’s a cool, foggy morning in the Marin Headlands as volunteers and staff start their morning routines at the Marine Mammal Center in Sausalito.

This being the Bay Area, the cool and foggy part of this story isn’t newsworthy—but the scores of emaciated sea lion pups that have deluged the center in recent weeks? They’re making the news all over.

The pups have been rescued from beaches all the way up to Bodega Bay, and the center expects the wash-ups to continue for months to come. For the third year running, the pups were driven out of the Channel Island rookery before being weaned.

The culprit? The ocean water is too warm, and the sea lions’ anchor foods—anchovies and sardines—have dispersed.

As a result, adult sea lions can’t keep up with feeding themselves, let alone their pups. Now the center is scrambling to handle an influx of pups during what’s usually a slow time of year at the world-class animal-rescue center.

The animals being rescued are typically around eight months old, says Dr. Shawn Johnson, lead veterinarian at the center, “and half the weight they are supposed to be.” Sea lions, he says, will typically stick with mom until about their 11th month.

The Sausalito center houses a full-scale veterinarian hospital and necropsy lab on the site of an old Nike missile base.

It’s a popular destination for school groups, but the scene is kind of sad out back today. An outdoor pen finds about eight pups huddled on a heating pad. “We had to buy the heating pads,” says Johnson. “The little ones aren’t usually here this time of year.”

Where you’d expect blubbery beasts, you see instead the animals’ ribs. “They should still be in the Channel Islands nursing,” says Johnson.

Once the pups get their strength back, they are transferred to a saltwater pool to get them ready for the journey back to the sea. Between 50 and 60 percent of the pups that come here are released back to sea in Pt. Reyes National Park. The rest wind up at zoos and aquariums, or they die.

“This is normally the slow season,” says Johnson. He says a more typical winter morning would find vets, researchers and other staff catching up on scientific papers and maintenance projects around the facility.

Johnson says there are usually 10 to 15 animals onsite in January and February—sea otters, sea lions, harbor seals. That’s about how many sea lion pups are now coming into the center every week. In late February, there were about 150 in the facility—and more on the way. Almost 1,000 pups have been found stranded this year.

Earlier in the morning, Johnson had been on a conference call with a biologist at the Channel Islands. The news is not good from Southern California. “We are bracing to be at or near capacity in a few weeks, and it’s making us all very nervous,” says Johnson. “It’s bad timing.”

Volunteers have been called in, and the center issued an online “SOS” for new ones. The center was coming up short on medicine and food, so there’s been a push in fundraising at the nonprofit, whose annual budget is around $6.5 million.

Temporary volunteers are put to work in the spacious “fish kitchen,” where they sanitize items used to feed the sea lions. Trained volunteers prepare the food and feed the animals. For healthier sea lions, there are buckets of fat Alaskan herring; sicker animals get a liquid mix of herring, fish oil and water.The center goes through 400 pounds of $1-a-pound herring a day trying to save the stranded pups.

The pup wash-ups are driven by rising ocean temperatures, says Johnson. Those have been running 2 to 5 degrees Celsius above average, from the Aleutian Islands all the way down to Baja California, despite the apparent absence of an El Niño trigger.

The warming trend has dispersed the anchovies and sardines that sea lions rely on, says Johnson. “The sea lion moms are not eating too much themselves, but they are putting lots of effort into finding food. They can’t keep up.”

There’s a ripple effect up and down the chain when a “sentinel species” struggles.

“It’s very concerning to us,” Johnson says. The health of
these apex predators “is a good indicator of the general health of the ocean. If sea lions can’t find enough food for themselves, what does it mean for other [sea creatures],” he says—let alone fishermen trying to make a