Marine mammal rescuers are dealing with an unprecedented influx of sick seals at the Marine Mammal Center Morro Bay triage center.
So far this year, at least 84 sea lions, 63 elephant seals and five harbor seals have passed through the Morro Bay facility. The animals are suffering from either starvation or poisoning from toxic algae blooms, said Shawn Johnson, director of veterinary science at the center’s headquarters in Sausalito.
“It’s been a perfect storm,” he said. “We’ve been the busiest we’ve ever been at the center.”
The Marine Mammal Center serves most of Central and Northern California. Animals that are rescued along the Central Coast are brought to the Morro Bay facility to be stabilized for several days and readied for transport to the main hospital in Sausalito. A seal is typically rehabilitated for four or five weeks before it is ready to be released back into the wild.
This year, the center has rescued 658 seals from its entire California coast service area. The center typically gets 600 animals a year, but they have already surpassed that number with five more months to go.
“The good news is that we have already released 330 animals,” Johnson said.
Most of the sea lions are juveniles that have weaned prematurely and are not able to fend for themselves, Johnson said. Normally, a sea lion pup will nurse until May but many were abandoned by their mothers in March and April.
“We think it is a lack of food availability in the Channel Islands where their rookeries are located,” Johnson said. “The moms could not feed the pups and abandoned them.”
About a quarter of the sea lions are suffering from domoic acid poisoning. Domoic acid is a toxin that is produced by some algae blooms and accumulates in the tissue of sardines and anchovies, a favorite food of sea lions. Domoic acid causes brain damage and seizures in sea lions.
“They get a huge dose of that toxin,” he said. “We’ve been seeing a really high number of domoic acid cases, mostly in Monterey and San Luis Obispo counties.”
On Saturday, two sea lions were being nursed at the Morro Bay Center after suffering seizures probably brought on by domoic acid poisoning, volunteer Aubrey St. Marie said. One was found Friday in Morro Bay and one early Saturday in Cayucos.
The reason for the large number of sick elephant seals is not known. The seals are typically pups from the Piedras Blancas rookery that have not learned how to forage for themselves and end up on local beaches looking malnourished.
As the summer progresses, the animal rescue volunteers have something else to worry about. Some forecasters say there is a strong probability that next winter will be an El Niño winter with heavy rain and powerful storms possible.
Although many people are hoping an El Niño will break the state’s profound drought, the weather phenomenon causes many problems for marine mammals including disruption of the marine food chain and heavy surf washing seal pups off the beach.
“We are definitely concerned and preparing for an El Niño next year,” Johnson said.