Aggressive sea lion encounters have been reported along California's coastline. Explanation provided.
Rewritten Article:
Up and down the sun-kissed Southern California coastline, friendly and playful sea lions have taken a weird turn, launching attacks on humans swimming in the water. These marine creatures are in distress, contaminated by the ocean they call home according to experts, with reports of sick sea lions reaching unprecedented levels and many succumbing to their poisoning.
Just 15-year-old Phoebe Beltran, a resident of Long Beach, was swimming on March 30, when a sea lion went for her right arm. Recalling the incident to CNN affiliate KCAL, Beltran described feeling "so scared, so shocked, but still experiencing intense pain on my arm, like, again and again." Despite the bites, bruises, and scratches, she didn't require stitches, she said.
Up the coast in Ventura County, a surfer near Oxnard had a close encounter on March 21. The sea lion caught him by surprise, charging from the water towards RJ LaMendola at top speed. According to LaMendola's social media post, the attack left him deeply shaken and traumatized. He wrote that the sea lion's "expression was feral, almost demonic, devoid of the curiosity or playfulness I'd always associated with sea lions."
The culprit is more likely domoic acid poisoning caused by toxic algal blooms, often referred to as "red tide," say experts. John Warner, CEO of the Marine Mammal Care Center in Los Angeles, told CNN, "The sea lions are coming in almost comatose by the time they're stranding. Something is happening in this particular bloom that seems worse on multiple levels." He added that this season has been the worst the center has ever experienced.
Similarly, dolphins have been affected. When the neurological toxin gets into sea lions' food supply, it inhibits their breathing and causes seizures, including a type called "stargazing" when sea lions extend their heads back for an unusually long time with their eyes closed. Warner explained, "when they are affected with this toxin, they're out of their minds... they're scared, totally disoriented and frightened... They're struggling to even get out of the water, so they don't drown."
In these disoriented and panicking states, sea lions react in a hyper-energetic and aggressive manner. If a person swims or walks past them, unexpected interactions can occur. Warner stated, "if someone swims or walks next to them and they don't see the animal or the animal doesn't see them, that's where some negative interactions can take place."
![A sea lion ailing from suspected domoic acid poisoning is retrieved by local volunteers in Santa Barbara, California, for medical assessment on March 25, 2025. [Captured by David Swanson / AFP] [Courtesy of DAVID SWANSON/AFP via Getty Images]](https://asb-media.info/en/img/20250406133249_california-sea-lion-rescue-santa-barbara-domoic-acid-poisoning-march-25-2025-david-swanson-afp-getty-images.jpeg "Maladed California sea lion, suspected to have been affected by domoic acid poisoning, retrieved by local volunteers for assessment in Santa Barbara, CA, on March 25, 2025. (Image by David Swanson / AFP) (Image by DAVID SWANSON/AFP via Getty Images)")
The center gets about 3,000 to 4,000 calls per year regarding sick and stranded animals when there isn't an emergency. In the past five weeks alone, they've received over 2,000 calls to their hotline, a situation Warner compared to a "tsunami."
The True Cause: Human-Induced Climate Change and Toxic Algal Blooms
Domoic acid is found naturally in the Pacific Ocean. However, a process called upwelling, caused by strong coastal winds, brings the acid into the aquatic food chain. As cold water is churned up from the ocean floor, it carries nutrients and nourishes smaller marine organisms that serve as food for larger species, such as sea lions, dolphins, pelicans, whales, and various kinds of fish. Algal blooms, fueled by nutrients in the water, generate copious amounts of toxic algae, thereby entering the food chain.
Human activities, including climate change and excessive land development, intensify the impact of the algal blooms. Warmer ocean temperatures and increased acidity promote the proliferation of algae. Agricultural runoff of nitrogen fertilizers also feeds the algal blooms, just as it enriches land-based plants. Previously, such blooms occurred every few years, but now they happen annually.
The recent toxic events are more severe than ever, with ocean toxicity levels higher this year. Warner estimates that 50% to 65% of animals will recover and return to the ocean, but a lower survival rate is expected this time compared to previous blooms. This year's events have already seen an increase not only in the number of sick animals but also in the intensity of their sickness.
Healing the Affected Animals
About 80% of the sea lions treated by the center this year are pregnant, Warner surmises. The toxic domoic acid forces many expectant mothers to expel their fetuses to survive. Warner emphasized the importance of keeping the mother pregnant, because "every day that the mom still is pregnant is really affecting whether she will survive this." The overall sea lion population remains robust, but this trend could have long-term consequences for the species.
To bring the animals back to health, the Marine Mammal Care Center tries to flush the water-soluble toxin out of the sea lions. This involves giving them anti-seizure medications to prevent permanent brain damage, along with plenty of fluids and nutrition. Initially, they tube-feed the sea lions twice a day. However, this year, recovery has taken longer, and they try to get the animals back to the ocean as soon as possible so that they can treat more sick animals.
They've also established a triage site in their parking lot to care for around 25 additional animals. However, their budget for the year includes treatment for only 300 animals, so they face financial constraints in handling the current crisis.
Domoic acid poisoning is fatal for dolphins. This season has been the worst the center has witnessed for dolphins, with over 70 strandings in Los Angeles County alone. Unfortunately, there's little hope for rehabilitation, and most dolphins who strand are already deceased. The best they can do is to humanely euthanize those still struggling on the beaches. As of the end of March, the center has treated 240 animals, but their budget only covers 300 for the entire year.
LaMendola, the surfer attacked by a sea lion, was near the Channel Islands, the main breeding ground for California sea lions. A higher number of baby sea lions and elephant seals are now stranding, adding to the ongoing crisis.
This toxic crisis highlights the need for long-term solutions to mitigate the effects of climate change, pollution, and human activities on ocean health and marine life.
- The strange behavior of sea lions along the Southern California beaches could be linked to their contaminated environment, as the high levels of sick sea lions are attributed to toxic algal blooms, often caused by human-induced climate change.
- In light of the current crisis, the Marine Mammal Care Center in Los Angeles is working tirelessly to rehabilitate affected animals, providing nutritious food and anti-seizure medication to help them recover from domoic acid poisoning. They've established a triage site for around 25 additional animals but face financial constraints, as their budget only covers treatment for 300 animals annually.
- The increased toxicity levels in the ocean this year have led to severe consequences for not only sea lions but also dolphins, with over 70 strandings in Los Angeles County alone. Unfortunately, most of the dolphins are beyond rehabilitation, and the center provides humane euthanasia for those still suffering on the beaches.
