Hundreds of sea lions and dolphins are turning up severely ill or dying on Southern California’s beaches as the region experiences what one wildlife group says is the worst so-called red tide they’ve ever seen.

Since June 8, more than 100 dolphins and more than 100 sea lions have died in the Santa Barbara area because of domoic acid toxicity from algal blooms, according to Sam Dover, executive director of the Channel Islands Marine & Wildlife Institute.

Before June 8, he said the institute was maybe getting one call a day about a sick animal. Now they’re getting over 300 calls a day.

“We’ve never had numbers this high. It’s just out-of-control high,” Dover said. “This is the worst in my lifetime.”

In Los Angeles County, the Marine Mammal Care Center has reached its capacity because of the “exceptionally high” number of sick animals. The ailing sea lions and dolphins also are turning up farther south in Orange County and San Diego as the toxic algal bloom spreads.

Here’s what you need to know about California’s red tide:

What’s happening

A dolphin that succumbed to domoic acid toxicity.

Sea lions and dolphins have been showing up on California beaches with seizures or passing out, even dying, Dover said.

“I’d see one and 100 yards down beach another, and another, and another,” he said. “It became overwhelming pretty rapidly.”

It started in Santa Barbara, which remains the epicenter of the problem, and it has spread farther south and north in recent days.

Dover and other volunteers must decide whether to cordon off an area to give the animals room to hopefully recover, whether to bring them in for treatment or whether euthanasia can help a suffering animal that’s past the point of being able to survive.

If they’re brought in for treatment, Dover said they’re given fluids, food and anti-inflammatories, all of which can help flush the toxins from their bodies.