VENTURA, Calif. — Hundreds of sick and dying seabirds and seals have been washing up on beaches in Ventura and Santa Barbara counties, CBS Los Angeles reports.

Elaine Ibarra, who works with the Santa Barbara Wildlife Care Network, estimated hundreds of pelicans and loons have died.

She blamed domoic acid, which is a naturally occurring toxin in plankton that fish eat. Then, other marine wildlife eats the fish.

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There is a bigger than normal plankton bloom this year, Ibarra explained, and depending on how much the animals eat, it can be fatal.

"That could be from temperature, runoff. We've had a lot of rain this year, so some people are speculating that it might have to do with the runoff into the water," she said.

Ibarra said it's normal to see seals and birds die during this time of year from domoic acid, but she has never seen so many.

Ventura County is getting hit the hardest, she added.

"They're very stressed out, and it is really hard to see something have a seizure and know there's very little that you can do to help," the animal care coordinator said.

She said it is impossible to predict how long the plankton bloom will last but it may not end until early summer.

Kyle Cory often walks on Silver Strand beach and sees the ill sea birds all the time.

"I can see anywhere between 6 and 12 every walk. So there's something going on," he said. "It's affected me in a bad way because it's just not good to see on the beach."

He said he will keep documenting the dead wildlife he sees, hoping it'll somehow help.

"How many have to die before somebody cares?" he asked.

Experts said there have been no reports of humans getting sick from domoic acid but advised people to avoid eating shellfish during the plankton bloom.