Along the scenic shores of California’s Central Coast, a quiet crisis has been unfolding — one that is tragic, troubling, and all too familiar. Since February, over 150 dolphins and sea lions have been found dead along Santa Barbara County beaches, casualties of a toxic algal bloom driven by warming oceans and environmental shifts.
The culprit is domoic acid, a naturally occurring neurotoxin produced by certain species of algae. When conditions are right — warmer water temperatures, nutrient runoff, and changes in ocean currents—these algae can bloom in massive quantities. Small fish like anchovies ingest the toxin, and when sea lions or dolphins eat those fish, the effects can be devastating.
Organizations such as the Channel Islands Marine Wildlife Institute (CIMWI) and the Channel Islands Cetacean Research Unit (CICRU) have been on the front lines of the response. The symptoms they’re seeing are heartbreaking: marine mammals coming ashore disoriented, foaming at the mouth, convulsing, or worse. In some instances, the toxicity has led to dangerous behavior — like a recent case in Ventura County, where a likely poisoned sea lion bit and dragged a surfer from his board.
“This neurotoxin is crippling and killing sea lions and dolphins,” said Ruth Dover, managing director of CIMWI in an interview with the Santa Barbara Independent. “It’s heartbreaking for beachgoers to witness, and it’s exhausting for our team.”
Though sea lions have a slightly better survival rate when treated quickly — about 50 percent — dolphins are far more fragile. According to Michelle Berman Kowalewski, founder and director of CICRU, dolphins are particularly vulnerable due to their physiology and instincts. Adapted to deep, cool waters, they panic when weakened and pushed ashore by the tide. Once stranded, their thick insulation works against them. “They almost start to cook on the inside because they can’t dump their heat enough to cool off,” she explained. “They’re already sick, they’re panicked, they’re overheating, and there’s just very little chance for survival at that stage.”
This year’s bloom may not yet rival the catastrophic event of 2023 — when CICRU responded to 120 dolphin deaths in a single month — but the numbers are rising. Since February, CICRU has already logged more than 50 dolphin deaths, well above the annual average of 30 to 40. CIMWI is seeing similarly grim figures, responding to around 150 distress calls per day, with a 90 percent fatality rate. Despite these challenges, there have been bright spots. CIMWI has successfully rehabilitated 10 animals this season, including a young seal pup rescued from Hendry’s Beach.
Historically, large domoic acid blooms occurred every four to seven years. But now, blooms are being recorded every year, and they’re happening earlier than ever. What used to be a springtime issue now begins in February, adding stress to already fragile marine populations. Scientists like Alyson Santoro, a marine microbiologist at UC Santa Barbara, say the reasons are complex and intertwined. “We’re changing so many things at the same time — it’s hard to nail down any one thing,” Santoro said.
Warming ocean temperatures, altered upwelling cycles, increased acidification, and excessive nutrient runoff from storms and wildfires are all likely contributors. One new concern: phosphorus-based fire retardants from recent wildfires in Los Angeles may also be feeding this year’s bloom.
Santoro’s lab, which samples harmful algae blooms at Stearns Wharf as part of the Southern California Coastal Ocean Observing System, plays a key role in tracking these shifts. But she warns that monitoring programs are under constant threat due to funding cuts, especially from the National Oceanic and Atmospheric Administration (NOAA). “The only way you can really understand these things is sustained observations over a lot of years,” she said. “And that’s not a very sexy thing. People want a solution now, and so these programs are always on the chopping block.”
The reality is this: human activity is making the oceans more hospitable to harmful blooms, and wildlife is paying the price. As marine life faces rising stress from climate change and habitat disruption, their ability to withstand toxins like domoic acid is weakening. Each new bloom compounds the damage, creating a cycle that’s increasingly difficult to break.
If you encounter a distressed sea lion or dolphin, do not approach. Maintain a distance of at least 50 feet and immediately contact CIMWI at (805) 567-1505 or CICRU’s dolphin stranding hotline at (805) 500-6220. Reporting location details quickly can give marine rescue teams a fighting chance to help.
While this story is sobering, it also serves as a reminder of the delicate balance between ocean health and human influence. As the frequency of these blooms rises, so too does the urgency to act — by protecting marine environments, reducing pollution, supporting long-term scientific research, and respecting the wildlife that call our coastlines home.
