The Hidden Victims of Wildfires: Marine Mammals?

Think about the Southern California wildfire back in 2025. Burning hillsides, orange skies, and neighborhoods reduced to ash. So we assume that animals living on land are the only victims. But is this really true?
During a recent interview with R. Privitera, a manager at the California Marine Mammal Center, it became clear that wildfires are not only devastating forests and homes but also indirectly poisoning the ocean.
And the victims are marine animals.
Wildfires release massive amounts of ash, debris, and ‘nutrient-rich’ runoff into coastal waters. These nutrients, especially nitrogen and phosphorus, easily wash into the ocean when rain follows fire seasons.
The result? Explosive algae blooms.
Some species of algae produce ‘domoic acid,’ a powerful neurotoxin. Small fish like anchovies and sardines eat the toxic algae. Large predators, such as sealions, eat those fish. The toxin follows the food chain pyramid. Seeing how many sea lions are being rehabilitated in the center due to the domoic acid problem really substantiates this.
According to Privitera, affected sea lions often arrive disoriented or actively seizing. Some display unusual aggression. In severe cases, domoic acid causes death. What makes this especially alarming is that the connection is not obvious. A wildfire kilometers inland can eventually lead to a neurological crisis in marine mammals along the coast.

Algae blooms are not entirely new to California’s waters. However, the frequency and intensity of toxic blooms appear to be increasing.
Privitera explained that during major bloom events, the Marine Mammal Center sees a dramatic increase in patients. Facilities become overwhelmed. Some sea lions recover with treatment. Others do not.
This isn’t a single isolated event. It’s becoming a recurring pattern.
Climate change plays a critical role. Warmer ocean temperatures create more favorable conditions for harmful algae growth. At the same time, stronger and more frequent wildfires produce larger amounts of nutrient runoff.
We often categorize disasters separately. But the systems are interconnected. Forest, river, and ocean. Fire does not stop at the shoreline.
Wildfires are not just a land issue. Algae blooms are not just an ocean issue. Climate change is not just an atmospheric issue.
The crisis affecting sea lions is not an isolated event; it is evidence of how closely land and sea are connected and how far the consequences of climate-driven disasters now reach.
Image cited:
NOAA Fisheries. “Toxic Algal Bloom Suspected in Dolphin and Sea Lion Deaths in Southern California.” NOAA, 2023, www.fisheries.noaa.gov/feature-story/toxic-algal-bloom-suspected-dolphin-and-sea-lion-deaths-southern-california. Accessed 1 Mar. 2026.










