Many Southern California beachgoers have at some point seen a sea lion lolling lethargically on the sand, sometimes surrounded by orange cones to keep people from disturbing it.

That sight has become much more common in the past few weeks, as a toxic algae bloom has sickened dozens of the usually playful pinnipeds and caused them to strand themselves on the shore.

The nonprofit Marine Mammal Care Center in San Pedro has been responding to the crisis, taking in about 100 California sea lions poisoned by domoic acid, which comes from an algae called Pseudo-nitzschia.

“Most of the time the ocean is a diverse place with lots of types of algae,” said Dave Bader, chief operations and education officer at the Marine Mammal Care Center – but when conditions are right, Pseudo-nitzschia can take over.

It gets eaten by small ocean organisms and fish, which are then eaten by sea lions, pelicans and other animals. If they ingest enough of the neurotoxin, sea lions may become lethargic or aggressive or behave strangely, bobbing their heads as if drunk. It can even cause seizures and death.

Bader said there’s no antidote, but humans can help nurse wildlife back to health.

“The critical thing is to get to an animal as quickly as we can,” and give a sea lion fluids to flush out the toxin, provide anti-seizure medication if needed and feed it uncontaminated fish, he said. The center gives the animals a place to rest and recuperate, with its fenced-off enclosures containing pools they can swim in.

When there’s not an explosion of toxic algae, the Marine Mammal Care Center typically sees younger pinnipeds who have been weaned from their mothers but became stranded after being unable to find enough food on their own.

After admitting 66 animals from January through early June, the center took in 99 sick sea lions just in the month leading up to the July 4 holiday, Bader said, adding, “we’re definitely bursting at the seams.”

Center staff and volunteers are thawing more than 1,000 pounds of frozen fish a day to feed their patients. They’ve already run through the 150,000 pounds of herring that was expected to last the whole year, and they’re about $500,000 over their annual budget, Bader said.

The good news is some of the earliest patients that came to the center in June are doing well and will be ready for release soon. The less good news, Bader said, is that with oceans warming, becoming more acidic and being flushed with nutrients that boost the algae (such as in urban and agricultural runoff), “what we are seeing is an increase in the frequency and intensity of these types of algae blooms.”

To learn about volunteering, donating and other opportunities to support the Marine Mammal Care Center, click here.

Editor’s note: This story has been updated to clarify the timeline of how many animals the Marine Mammal Care Center has seen this year.

Public should stay away from sick sea lions, use caution in eating seafood, officials say