Domoic acid, a toxic substance naturally produced by marine algae, is now believed to cause memory loss in sea lions, which leads them to be washed ashore, disoriented and suffering.

University of California researchers concluded that when ingested by sea lions, the domoic acid toxin affects the hippocampus area, known to be the center of memory and emotions of the brain, making the sea lions lose their ability to navigate and find food, according to Yahoo News.

For the study, the researchers conducted behavioral tests and MRI scans on 30 California sea lions that were found stranded by the Marine Mammal Center in Sausalito, north of San Francisco, as published in the journal Science.

"In this study, we were able to correlate the extent of hippocampal damage to specific behavioural impairments relevant to the animals' survival in the wild. This is the first evidence of changes to brain networks in exposed sea lions, and suggests that these animals may be suffering a broad disruption of memory, not just spatial memory deficits," said Peter Cook of Emory University, leader of the research team, according to The International Business Times.

Now that the scientists are able to link the toxin to the memory loss and shore stranding of sea lions, they can continue the project, this time, in order to determine just how much domoic acid is needed to trigger the brain damage.