Toxic Algae May be Causing Brain Damage and Memory Loss for California Sea Lions

Sea lions may be being poisoned by toxic algae. Scientists have done brain scans and behavioral tests of California sea lions that stranded on shore and found that an algal toxin may be disrupting their brain networks.

Blooms of toxic algae typically occur in the spring and fall along the California coast. However, these blooms have been increasing in frequency and severity. Hundreds of sea lions strand on California beaches every year with symptoms of domoic acid poisoning.

In this latest study, the researchers studied 30 California sea lions undergoing veterinary care and rehabilitation. Researchers examined the animals' spatial memory and performed MRI to see the extent of brain lesions.

The researchers could actually see structural damage in the brains of affected sea lions, especially in the hippocampus. This looped structure in the center of the brain is known to be important for memory processes in humans and rodents. Animals with damage to the hippocampus showed impaired performance on short- and long-term spatial memory tasks.

"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, one of the researchers, in a news release. "We don't know exactly why the algae lead to the strandings. But sea lions are dynamically foraging-and for an animal like that, if you don't know where you are, you have a big problem."

The findings reveal that these blooms may be impacting the brains of sea lions. With repeated exposure, sea lions may be more prone to strandings.

The findings are published in the journal Science.

Related Articles

How Skates and Rays Evolved Their Wings

How Earth's History Influenced the Evolution of Birds and Their Diversity

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).