Algae bloom suspected of sickening sea lions

Jul 21, 2017

A Central Coast marine mammal center is currently treating over 20 ailing sea lions that have washed up on San Luis Obispo County beaches this week.

Diana Kramer is operations manager for the Marine Mammal Center’s facility in Morro Bay.

“We are now getting a tidal wave of California sea lions that are stranding onshore in SLO county. All of them - for the most part - presenting the same symptoms: confusion, disorientation, a very classic head weaving or bobbing, confused look, and sadly, some of them with seizures as well,” Kramer said.

The animals are most likely being poisoned by domoic acid toxicosis. The neurotoxin is naturally occurring, produced by algae. Kramer said staff had not yet conclusively diagnosed the animals, but that the symptoms seen are classic of that issue in sea lions.

“When we have a large bloom of that algae and an increase in the toxin produced, what happens is the fish or shellfish eat that algae, they become full of that toxin, and then when the sea lions eat those things, it builds up in their system and causes these symptoms we are seeing,” Kramer said.

This latest slew of sick animals started Monday when the center got a call about what appeared to be a sick sea lion on the beach in Oceano. When Kramer and her team went to go investigated, they came across other sea lions washed up on the beach as well.

Since the facility in Morro Bay is akin to an emergency room for sea mammals, the animals are stabilized locally for a few days, then transported to the main hospital in the Bay Area, for longer-term care. Kramer says the most important treatment is hydration to flush out the toxin. Most of the animals should recover.

If you come across what looks like a sick sea lion on a beach, Kramer says please give it a wide berth.

“If they see something on the beach that might be sick, giving it that space...these animals are sick and not feeling well, so giving it at least 50 feet of distance and giving us a call,” is the best action, Kramer said.

To report a distressed animal, call 415-289-SEAL.