HUNTINGTON BEACH, Calif. (KABC) -- The largest algae bloom on record is taking place off California's central and southern coast, and over the last few weeks it has sickened and killed hundreds of sea lions and dolphins.
"The size of this one again and the numbers of animals that are coming ashore is large," said Justin Viezbicke, California stranding coordinator for the National Oceanic and Atmospheric Administration. "Larger than we've seen really in the last, I'd say close to probably 20 years."
Viezbicke said while there is no risk to humans through water contact, sea mammals like sea lions and dolphins are getting sick from suspected domoic acid toxicity, which happens after eating contaminated food.
"It's created this opportunity for this algae to grow, basically, so it's growing and it's gotten to the point where there's enough of it out there," Viezbicke said.
Viezbicke said it's worked its way through the food chain, resulting in marine mammals eating contaminated fish.
Marine Mammal Care Center CEO John Warner said the bloom is causing a large influx of sea lions to be stranded on beaches up and down Southern California coasts.
He said they're treating them as fast as they can but an unknown number of sick sea lions remain on the beaches.
"To feel helpless, to be full and know that there's animals in need is probably the worst experience for all of us who work here and are volunteers as well," Warner said.
Viezbicke urges people to stay away from stranded sea lions because they may be under distress and be aggressive.
"We've had a number of bites that have been reported in Santa Barbara, L.A. and Orange counties," he said. "When these sea lions are affected by this neurotoxin there is definitively an increase chance for harmful interactions between humans and animals."
Beachgoers who see a stranded or dead animal on the beach are encouraged to report it by calling the NOAA at 866-767-6114.