As the days get longer and the summer sun grows closer, beachgoers flock to enjoy tanning, catching waves and walking along the sand, but under the ocean’s picturesque waves lies a toxic problem: domoic acid. Produced by a microalgae species, the toxic bloom has occurred for several consecutive years along the Southern California coastline, affecting both marine-life and humans. Although the bloom only lasts a few weeks at a time, its effects are devastating to local marine life, and disturbing for humans who come across affected animals.
This toxic algae bloom event occurs at warm temperatures naturally, but with global ocean temperatures rising, the bloom will not only become more frequent, but in higher concentrations as well. Specifically, this algae bloom is a species of plant-like microorganisms known as “pseudo-nitzschia australis,” which produces a toxin called domoic acid. In warm weather conditions, the algae can rapidly reproduce, causing a massive spike in the population and subsequently damaging the local ecosystem. Pollution also contributes to these conditions, from “human activities like increased fertilizer use and sewage runoff as well as warming waters due to climate change create the types of conditions in which algal blooms like these thrive,” according to the Mammal Marine Care Center, a conservation and rehabilitation organization.
The algal bloom is absorbed by the smallest animals in the food chain, such as fish, which other larger animals — dolphins, sea lions or seabirds — prey on, and through a domino effect, the toxins spread up the food chain.
In sea lions, the domoic acid can target vital organs, cause nerve damage and seizures or bobbing movements. This may also make them aggressive or unpredictable when beached. Dolphins, another species affected by the algal bloom, will swim in shallow circles, become confused or even wash up on the shore. For seabirds like pelicans or cormorants, eating fish high in domoic acid can mean severe injury or death.
Jamie King, a Senior Conservation Biologist for the resource conservation district of the Santa Monica Mountains (RCDSSM), which is a locally funded state agency, has seen firsthand the effects and damage due to this event. King stated that as a past state park employee and a land manager, she’s seen “ill birds or mammals behaving oddly on the beach,” as a result of domoic acid poisoning. More specifically, she has spotted “sea lions, sitting up on the beach, which they normally wouldn’t do for long periods of time or waving back-and-forth physically.”
Recently, many surfers and beachgoers have reported on social media accounts of aggressive behavior, mainly exhibited by sea lions. While sea lions aren’t entirely docile creatures, they typically do not attack unless provoked. However, a local Ventura County surfer named RJ LaMendola was violently attacked by a sea lion while surfing off the coast of Oxnard. According to The Inertia, this incident could potentially be linked to the toxic algae bloom, as sea lion bites are extremely rare, and this behavior is one of the main symptoms of domoic acid poisoning.
Antal Szijj, a local ecologist for the Army Corps of Engineers, shared a more emotional sentiment regarding the effects of this event. “I’m sure they’re [beachgoers] saddened to see animal carcasses on the beach,” he said. “[It] has the effect of making [the bloom] more real to them.”
While the situation is saddening, the severity of this event may help to draw attention to one of Earth’s most prevalent issues: climate change. Both King and Szijj agreed that most people are unaware of what goes on in the ocean, and why these events occur. Drawing attention to the toxic algae bloom helps to keep local beach-goers and marine life safe from dangerous situations.
