Toxic algae put sea lions in a serious trouble. A new study published in journal Science has reported that the sea mammal is increasingly exposed to a neurotoxin that is causing brain damage.

The neurotoxin is hurting sea lions’ spatial memory and making them prone to getting confused and forgetting their path, according to the study. It may be the reason why the creature has been seen in huge numbers stranded on the west coast.

The study said humans could not be blamed this harmful neurotoxin as marine algae produce it naturally. Tiny sea creatures amplify the neurotoxin by consuming it. Domoic acid, marine algal blooms responsible for the neurotoxin, thrives under warm ocean waters, which is a result of global warming. It means humans might be blamed for sea lions’ problem, the study explained.

Scientists said domoic acid’s neurotoxic effects are not new. They started studying the neurotoxin’s effects more than two decades ago. Peter Cook, a researcher at Emory University and the study’s lead author, said he and his colleagues have been studying the domoic acid from last ten years when he was a graduate student at the University of California at Santa Cruz.

According to Cook, there are some neurotoxins that result in general brain damage, but the domoic acid causes specific lesions on the hippocampus. “It hadn't really been studied in marine mammals. People didn't see it as a large-scale ecological concern”, he explained.