KCBX Two-Way: Toxic algae may be affecting SLO County marine mammals

Jun 25, 2019

Summer has arrived on the Central Coast, and that means birthing time for sea lions and large gatherings of sea lions and other marine mammals. But something in San Luis Obispo County ocean waters may be affecting the behavior of area marine mamals. A recent video went viral of a sea lion biting a Paso Robles teenager at a south San Luis Obispo County beach. It's a rare event that could be the result of toxic algal blooms. 

To learn more, KCBX News’ Tyler Pratt sat down with San Luis Obispo Tribune reporter Gabby Ferreira in the KCBX studios.

TYLER PRATT: Gabby, you broke the story for the Tribune. What happened?

GABBY FERREIRA: A 13-year-old girl from Paso Robles was at Pismo Beach the Friday before last. She was in the surf a little bit north of the pier. Her friend was taking pictures of her standing in the surf at sunset. All of the sudden the sea lion, out of nowhere, came up and bit her on her thigh.

PRATT: Is she OK?

FERREIRA: She’s fine. From what I understand, she was taken to Sierra Vista Regional Medical Center after the attack. And California Department of Fish and Wildlife scientists were consulted to make sure that she got the right antibiotics because marine mammals have different bacteria in their mouths. I understand it was a nasty injury, but she's doing OK.

PRATT: You report this could have something to do with toxic algae. What's going on here?

FERREIRA: So [Fish and Wildlife officials] believe the sea lion they later found on the beach was suffering from demoic acid toxicosis, or demoic acid poisoning, which happens when marine animals, like sea lions, eat little fish and creatures that have been eating toxic algae. If these sea lions eat enough fish that have been eating toxic algae, they can get demoic acid poisoning from [them].

PRATT: [Fish and Wildlife officials] think they found a sea lion that might have been the one that bit the girl, and it was exhibiting the symptoms and acting weird?

FERREIRA: Yes, correct. Fish and Wildlife officials got to Pismo Beach after the girl had already been taken to the hospital. An officer on the beach saw a sea lion that was in the surf area and [it] was acting super weird. [The officer] followed that sea lion while it was in the surf. The sea lion swam down a little bit, got up on the beach, and started biting things like sticks. Then it made its way over to a lifeguard stand and started biting the base of the lifeguard stand, which is metal. That’s not normal sea lion behavior. So [Fish and Wildlife officials] thought, 'OK, the sea lion is exhibiting signs of demoic acid poisoning and it is most likely though sea lion that bit this girl.' They called the Marine Mammal Center, which took the sea lion to its clinic in Morro Bay to start treating it for demoic acid poisoning. The last I checked with Marine Mammal Center officials, that sea lion is up in Sausalito being treated at their main clinic.

PRATT: You report that there's been about two dozen instances of sea lions in our county over the past couple of weeks with this toxicity. Is there a risk to the sea lion population and is there risk to people?

FERREIRA: From what I understand, that number—two dozen from SLO County—that was on Wednesday when they gave me that number. I was told by the Marine Mammal Center they think there might have been some sort of algal bloom in our waters that the fish were eating that then the sea lions were eating that was causing this. So they have seen an uptick in sea lions that they're treating for demoic acid poisoning. They said most of the sea lions they've been finding have been in the Pismo Beach and Oceano Dunes areas. The algal blooms come and go. [Marine Mammal Center staff] said they do tend to see more demoic acid poisoning events in the summertime. So if you do see a sea lion that is acting weird on the beach you should call the Marine Mammal Center at 415-289-7325 [SEAL].