The Marine Mammal Center in Marin County is on the front lines of a statewide response to a surge in sea lion pups turning up on California beaches emaciated and sometimes sick, at a time they still should be in the company of their mothers, nursing and learning to forage.
Already this year, the rehabilitation center in the Marin Headlands has received at least 108 California sea lions in need of care — mostly pups, but some juveniles and adults, as well, staff veterinarian Cara Field said Tuesday.
Even more were in line to arrive from triage centers farther south Wednesday, facility personnel said.
The marine mammal hospital usually takes in just a few California sea lion babies in January of a given year.
The most ever was last January, when there were 10, so “we’ve received a huge increase,” Field said.
The situation is similar across the network of marine mammal care facilities on the West Coast, many of them based in Southern California, closer to the Channel Islands sea lion rookery and other off-shore breeding grounds reaching into Baja.
Scores of malnourished pups, their big, dark eyes appearing even larger than usual in their thin faces, are being rehabilitated, taxing the nonprofit centers that take them in.
“Looking at the data over the past 10 years, this is the busiest January on record, as far as strandings go,” said Justin Viezbicke, California Stranding Network Coordinator for the National Marine Fisheries Service.
Statewide, there were just more than 250 strandings by the end of January, he said.
At the Pacific Marine Mammal Center in Laguna Beach, 38 sea lions are in care.
The Marine Mammal Care Center at Fort MacArthur in San Pedro had 87 sea lions, including 78 pups and eight sea lions of other ages, said Raymond Simanavicius, marketing and development manager.
Statewide, it’s the third year in a row that an unusual number of enfeebled young sea lions have been rescued from the California shoreline. The underlying cause remains a mystery.
“We’re getting twice the number we did in 2013, but we don’t know what the reason is,” Simanavicius said, referring to an episode in 2013 when the high number of sea lion fatalities and strandings was officially elevated to what the National Oceanic and Atmospheric Administration calls an “unusual mortality event.”
The Marin Headlands facility, whose usual response area includes a 600-mile stretch of coastline as far south as San Luis Obispo, is caring for animals recovered from its usual territory, but most are from the Santa Barbara area, which has just been overwhelmed, Field said. Though sea lions frequent the Sonoma Coast, no stranded pups have been reported there, likely because most of those finding themselves in trouble are too young and too weak to have made it that far north, she said.
The continued problems for the state’s sea lion population have puzzled scientists.
It’s possible the coastal waters, with an estimated sea lion population around 300,000, has reached its carrying capacity, Viezbicke said.
It’s also true that the ocean along the coastline is warmer this year, but whether that’s affected the sea lions’ prey or predators isn’t clear.
“At this point we can only speculate on what factor or factors may be contributing to this,” Viezbicke said.