Stranded and Suffering: California’s Sea Lions Face a Growing Threat from Toxic Algal Blooms
- Kaia Africanis
- Apr 18
- 3 min read
Along California’s coast, a crisis is escalating. Sea lions are increasingly falling victim to domoic acid poisoning, a neurotoxin produced by harmful algal blooms that are becoming more intense and widespread. These blooms, driven by climate change and pollution, are wreaking havoc on marine mammals and ecosystems alike.
The Science Behind the Suffering
Domoic acid is produced by certain species of Pseudo-nitzschia, microscopic algae that bloom rapidly in warm, nutrient-rich waters. The toxin accumulates in fish like sardines and anchovies—mainstays in a sea lion’s diet—and moves up the food chain. Once ingested, domoic acid attacks the brain, causing disorientation, seizures, memory loss, and often death.
Neurological Chaos in the Wild
Sea lions affected by domoic acid often strand themselves, unable to navigate or survive in the wild. In 2023, more than 1,000 sea lions perished in one of the worst toxic bloom events ever recorded. Hundreds more were impacted in 2024, and by early 2025, SeaWorld San Diego had already treated 47 sea lions and 30 seabirds.
In a heartbreaking 2025 incident, a sea lion suffering from severe neurological damage attacked beachgoers before being euthanized. It was a stark reminder that the consequences of ecological imbalance are beginning to affect humans, too.
Climate Change and Runoff: A Dangerous Duo
Harmful algal blooms are flourishing under the combined pressures of warming ocean temperatures and nutrient runoff from agriculture. Climate change acts as a catalyst, warming the water and disrupting the marine food web. Meanwhile, excess fertilizers and manure wash into coastal waters, feeding blooms that poison marine life and destabilize entire ecosystems.
Permanent Damage, Even for Survivors
Survival doesn’t always mean recovery. Sea lions exposed to domoic acid can suffer long-term damage to the hippocampus, impairing memory and behavior. Mothers may abandon their pups. Some animals strand far from the ocean, confused and vulnerable. Even with rescue, many never regain the skills needed to live in the wild.
A Personal Reflection
This isn’t just another story for me—it’s a lived experience. While living in South Florida, I volunteered with the Marine Mammal Rescue Unit, spending long nights in rehab pools supporting dolphins after strandings. Many were calves, too weak to swim or stay conscious. Since dolphins are voluntary breathers, if they lose strength or awareness, they drown. We would rotate through shifts, gently holding them up so they could rest without slipping beneath the surface. I’ve seen how fragile life becomes when our oceans are broken. And now, watching sea lions suffer that same fate, I can’t stay silent.
Policy Rollbacks We Must Fight
These tragedies are not just environmental—they’re political. Several Trump-era rollbacks worsened the very conditions that now threaten marine life. We must fight to undo them:
Clean Water Act weakened: Trump’s Navigable Waters Protection Rule removed safeguards for wetlands and streams, allowing more nutrient runoff to pollute coastal waters.
National Ocean Policy dismantled: The shift away from climate and ecosystem resilience left marine conservation fragmented and underfunded.
NEPA and marine protections gutted: Fast-tracking industrial projects weakened oversight meant to protect marine mammals and their habitats.
Defunding of algal bloom monitoring: Critical NOAA and EPA programs tracking harmful algal blooms were slashed, limiting early response and public safety tools.
A Call for Action
We must act now—by restoring clean water protections, reinstating a science-based National Ocean Policy, funding marine mammal rescue efforts, and demanding climate accountability. Sea lions and dolphins are more than victims; they are sentinels. Their suffering signals the health of our ocean—and the urgency of our response.
Commentaires