Jules Leon climbed into a Ford pickup truck fitted with a net, a wheeled crate he calls a “moon buggie” and a defective winch. It was March 18 and Leon was on his way to Redondo Beach — for his third call of the day.
Leon, a responder with San Pedro’s Marine Mammal Care Center, checked in with lifeguards to confirm that a sick sea lion was last seen just north of the Avenue B Lifeguard Tower. Leon located the sea lion — which showed clear signs of domoic acid toxicosis — and, with the help of ocean lifeguard Charles Pogue, quickly captured and transported the mammal back to the Marine Mammal Care Center for treatment.
Next door to that center, at the International Bird Rescue faciltiy, senior wildlife rehabilitation technician Jennifer Martines did all she could to nurture cormorant chicks. Dressed in black from head-to-toe, including a full-face covering and a cormorant puppet, Martines fed the young as their mothers would.
The Marine Mammal Care Center, International Bird Rescue and other organizations, as well as elected officials, were in crisis-response mode.
That’s because Southern California’s 2025 toxic algae bloom was unprecedented — in scale, length and deadliness. Hundreds of dolphins and sea lions succumbed to elevated levels of domoic acid from San Diego to Santa Barbara. Not even birds were spared. Ultimately, multiple marine species — including some that hadn’t been affected before — required treatment. For months, from late winter to early summer, rescue centers nursed sick animals back to health and investigated why this bloom was so much worse than previous ones.
Dave Bader, the chief operating officer of the Marine Mammal Care Center, said that having toxic algae blooms of this magnitude for four consecutive years — two of which were record-setting — is telling about the overall health of the ocean.
“In previous decades, we would see a bloom like this every so often, maybe every seven years or so,” Bader said in a previous interview in April. “This acid bloom is early, and we’re on track to impact just as many animals, if not more.”
That came true.
The waters off the Los Angeles County coast began showing signs of a toxic bloom in February — for the fourth year running.
Though not typically an annual event, elevated levels of a phytoplankton fueled by nutrient-rich waters that produce a potent neurotoxin, domoic acid, have been regularly detected since 2022.
This year’s bloom came early. And in fewer than three months, the algae bloom had spread from San Diego, where it originated, to Santa Monica. A month later, it had migrated north of Santa Barbara.
“I don’t know what’s going on in the ocean,” said Alissa Deming, vice president of conservation and medicine and lead veterinarian at the Pacific Marine Mammal Center in Laguna Beach, said at the time. “Starting in February is unreal.”
The effects of the unusually early and large toxic bloom were immediate.
San Pedro’s Marine Mammal Care Center, for example, began fielding more than 60 calls a day regarding the bloom — with reports of sick and deceased animals up and down the coast. The daily routines of early morning surfers, dog walkers and lifeguards alike were interrupted by beached and sick dolphins, sea lions and birds, causing concern among beach communities across Southern California.
Besides domoic acid, which can cause gastrointestinal and neurological issues, the bloom also produced the “extremely deadly” saxitoxin, said Clarissa Anderson, director of the Southern California Coastal Ocean Observing System and biological oceanographer at the Scripps Institution of Oceanography in San Diego.
“This dual bloom event may intensify the impacts on marine wildlife,” the nonprofit Heal the Bay said in an April report, “contributing to the recent surge in animal distress and mortality along our coast.”
The impacts of the dual blooms were certainly palpable — as reports of sick animals increased for weeks along the coast.
As the toxic algae bloom continued worsening and the number of deceased mammals reached into the hundreds, various city leaders and organizations came together to address the crisis.
Keith Matassa of the Ocean Animal Response and Research Alliance analyzed and documented the results of numerous dolphin necropsies. The L.A. County Sanitation Districts organized a demonstration on how it monitors the health of sea life off the coast of San Pedro. Los Angeles Mayor Karen Bass met with environmental experts on June 4 at San Pedro’s AltaSea research facility to discuss the latest impacts of climate change — including the possible impacts of wildfire runoff.
Twenty days later, the Marine Mammal Care Center released two rehabilitated sea lion pups, Wren and Hue, to great fanfare in Hermosa Beach. In September, Ariana Gastelum and Kylie Clatterbuck of the International Bird Rescue released six rehabilitated western gulls at White Point Beach in San Pedro. Finally, on Friday, Sept. 19, members of the Aquarium of the Pacific released a rescued green sea turtle back into the wild near the San Gabriel River outlet in Seal Beach.
Looking to the future, AltaSea hosted an Ocean Tech Showcase on Oct. 7 that featured aspiring new advancements in ocean-centric technology. During the event, Andrew Thompson of Bluesonde Technologies Inc. presented a buoy that provides real-time water quality monitoring that could provide early detection of an approaching toxic algae bloom.
The bloom, as of October, had long passed — giving emergency marine responders a chance to regroup and prepare for the next one that may be on the horizon.
The International Bird Rescue currently has three birds still in its care, but hasn’t seen any additional birds with the same symptoms. The Marine Mammal Care Center only has six patients and none is suffering from domoic acid poisoning.
That center has now pivoted its focus to catching entangled sea lions and animals that are injured but otherwise healthy.
JD Bergeron, the International Bird Rescue’s CEO, said the 2025 harmful algae bloom was more complex because it involved numerous species of birds and was complicated by the fact that there were several toxins present this year — an uncommon phenomenon.
The 2025 algae bloom, Bergeron added, was a learning experience — and the IBR officials are writing up new response protocols and plans so they’re better prepared should the algae bloom crisis continue next year.
Bader, the Marine Mammal Care Center COO, said that facility is collaborating with the NOAA Westcoast Stranding Network to establish best practices to learn something from each bloom to be better prepared for the future.
“Climate change and its impacts are here today,” Bader said, “and we need to really get on board with slowing down the rate of change so that the negative consequences are lessened rather than ever increasing.”
Staff writer Erika Ritchie and freelancer Melissa Heckscher contributed to this report.