Hundreds of sea lions and dolphins along California’s southern coast are falling victim to toxic algal blooms.
In June, over 1,000 marine animals have fallen ill or died due to toxic algal blooms along California’s coast, as reported by the National Oceanic and Atmospheric Administration (NOAA).
The problem is exacerbated by climate change, according to experts. Rescue groups are receiving more than 200 daily reports of distressed marine mammals.
Sea birds, dolphins, and sea lions are particularly affected by the rapid growth of algae species producing the toxin domoic acid. The harmful algal blooms disrupt the food chain, with smaller marine creatures ingesting the toxins and passing them on to larger mammals.
“They eat a meal of those highly toxic fish and then they become toxified themselves, and if they get enough of that material, it of course can kill them, which is happening now,” said David Caron, a biological sciences professor at the University of Southern California.
The impact has been severe in Santa Barbara and Ventura counties. The Channel Islands Marine & Wildlife Institute, responsible for rescuing and treating sick animals, is struggling to keep up with the high number of distress reports.
Marine mammals affected by domoic acid can experience disorientation, seizures, and even death underwater.
Toxic algal blooms not only harm marine animals but can also pose risks to humans. Consuming fish contaminated with toxins can lead to illness, although the California Department of Public Health monitors toxin levels and closes shellfish beaches as needed.
It’s important to note that approaching stranded sea lions and dolphins should be avoided, as these animals may exhibit aggressive behavior due to the toxins. Instead, people should contact rescue organizations for assistance.
These organizations have been successful in rescuing and rehabilitating affected animals by providing them with food, fluids, and care until the toxins are flushed out of their systems.
While algal blooms typically occur between March and June in California, this year they may be peaking later due to the prolonged and rainy winter.
Climate change is believed to play a role in the expansion of harmful algal blooms, although not all species of algae produce toxins.
Warmer water temperatures associated with climate change create suitable conditions for the growth of harmful algae in new areas.
As a result, these blooms are spreading to previously unaffected regions. Scientists are actively studying the impact of climate change on coastal organisms and working to understand the intricate relationship between climate change and the proliferation of harmful algal blooms.
“But we have a fair amount of evidence, especially in inland waters, that climate change is exacerbating some of the problems that we’re seeing with harmful algae,” he said.