Researchers at the National Oceanic and Atmospheric Administration uncovered a correlation earlier this year between the interaction of the toxins DDT and domoic acid and the occurrence of epileptic seizures in California sea lions at the Channel Islands National Marine Sanctuary.
As reported by the Environment News Service, the researchers were aware that exposure to domoic acid, especially during brain development, caused sea lions to seize; but the increased threats from exposure to DDT have just recently been understood.
DDT is a synthetic pesticide that was banned in the 1970s for poisoning humans, wildlife and the environment. Due to its previous widespread use, it lingers in high levels in some areas, including the California coast. Though the presence of DDT is declining, the neurotoxin domoic acid is on the rise from harmful algal blooms produced by pollution and a warming climate.
The recent seizure research draws attention to the growing risks associated with algal toxins. Scientists are also exploring how the toxins’ interactions with other contaminants may harm marine mammals, as well as humans.