Sausalito’s Marine Mammal Center sees record number of stranded seal pups

Another species of marine wildlife has begun turning up, emaciated and weak, in record numbers on the California coast in what continue to be alarming signs of oceanic distress.

Unhealthy northern fur seal pups have been found stranded on beaches in record numbers, newly weaned and weighing little more than typical birth weight for the species, marine mammal experts said.

“They’re adorable, but on the other hand they’re these little bags of skin and bones,” said Jeff Boehm, executive director of the Marine Mammal Center near Sausalito.

As of Friday, the nonprofit center on the Marin Headlands had taken in 85 northern fur seals, which live out in the Pacific Ocean’s waters and islands and would only rarely be found on shore.

That number is more than double the previous record of 31 pups in 2006, according to the center.

“To have these guys up on our shores is the first sign they’re not well,” Boehm said.

Veterinarians estimate they are between 4 and 5 months old.

The majority turned up on shore in Santa Cruz and San Luis Obispo counties. One pup was found stranded in Mendocino County, two were found in Marin County and none has yet been rescued from the Sonoma Coast.

The seal pups likely were born on the Channel Islands in Southern California or the Farallon Islands about 30 miles beyond San Francisco’s Golden Gate.

The northern fur seal strandings are the latest in a string of alarming marine events. Experts have been working all year to address an “unusual mortality event” among California sea lions. In addition, wildlife rescue crews have been trying to rehabilitate a record number of the rarely seen and endangered Guadalupe fur seal pups, also showing up stranded.

The Marine Mammal Center began taking in California sea lions as early as December of last year, most of them malnourished pups who should still have been with their mothers, Boehm said.

Since then, the center has taken in 1,344 California sea lions. Boehm said it is possible that by the end of the year, they will surpass the last record of 1,356 California sea lions in 2009.

Experts believe the undernourishment of the sea lions and seals is directly related to a persistent band of atypical warm water, which some scientists have unaffectionately dubbed “the blob,” off the California coast that is causing shifts in the ocean environment and the availability of food.

Boehm said that the warmer water prevents nutrient-rich colder waters from rising and bringing a bounty of forage fish, primarily sardines and anchovies, into seal habitat.

Experts believe that is forcing mothers to leave their pups for longer periods of time in search of food. The mothers are underfed, and as a result so are their pups, Boehm said.

The warm-water trend could be extended with the El Niño weather pattern predicted this winter in the equatorial Pacific Ocean. “All the playbooks seem to be changing,” Boehm said.

You can reach Staff Writer Julie Johnson at 521-5220 or julie.johnson@pressdemocrat.com. On Twitter @jjpressdem.