If you see a sea lion acting weird, stay away. Probably just stay away no matter what, but now more than ever. Photo: Wikimedia Commons
If you’ve been on a beach in California more than a few times, there’s a decent chance you’ve run into a bunch of sea lions. It’s a nice experience, despite the smell. There are plenty of them along the stretch of beautiful coastline, but a toxic algae bloom seems to be making them far more aggressive than usual. Now, officials are warning anyone who runs into a sea lion acting funny to stay far away from it.
“If you see a sick sea lion on the beach, follow these steps,” wrote the Los Angeles County Department of Beaches and Harbors. “Stay away. Keep at least 50 feet between yourself and the animal. Do NOT try to pet the animal, take a selfie with it, put it back in the water, or do anything else that might stress the animal out. When stressed, the animals may become agitated and bite. Call Marine Mammal Care Center Los Angeles at 800-39-WHALE (94253) or, if you’re in Malibu, the California Wildlife Center at 310-458-WILD (9453).”
It’s likely that the sea lions are suffering from something called domoic acid toxicity, which is produced by an algae called Pseudo-nitzschia australis. It’s a phytoplankton that, during larger-than-normal algal blooms, releases a neurotoxin that builds up in the bodies of smaller prey. When a sea lion chows down on, say, a whole pile of sardines or anchovies, all that toxin that’s built up in the prey is passed along to the predator. Once it’s in the sea lion, the toxin hits the brain and heart. When things are normal, the toxin isn’t present in high enough levels to cause any problems, but when there’s a whole whack of it kicking around in a sea lion’s system, it can cause seizures and heart failure.
According to reports, the particular phytoplankton that’s producing the neurotoxin grows best when up-welling from the deeper ocean brings more nutrients to the surface. Those nutrients, as you’d expect, act as a kind of fertilizer. It’s entirely possible that El Niño is kicking that up-welling into higher gear.
Sea lions generally like to make their way to the Channel Islands around this time of year. It’s a nice place to give birth to a little baby sea lion, but this year, that trip to the nursery happened to coincide with the algal bloom. Now, marine mammal rescue teams are receiving up to 300 reports a day of sea lions behaving strangely. Over a hundred have been found dead, as well as more than a few dolphins.
“This is the worst domoic acid event to date, according to Alissa Deming, a vet at the Pacific Marine Mammal Center in Orange County,” wrote IFL Science. “It has led some sea lions to become violent if they are approached by humans.”
Domoic acid toxicity can manifest itself in a variety of ways, but according to the California Marine Mammal Stranding Network, disorientation, lethargy, bulging eyes, impaired locomotion, debilitated cognitive ability, rhythmic head bobbing and weaving, uncontrollable body movements, grand mal seizures, and being unresponsive, are the most glaringly obvious signs.
Domoic acid can mess up a human, too. It’s the same stuff that causes Amnesic Shellfish Poisoning, which one can get by eating a bunch of contaminated shellfish. While it’s more likely that you’ll just end up blowing up your toilet while simultaneously vomiting into your bathtub if you get it, there have been cases that ended in paralysis and even death.
