Toxic Algae Causing Brain Damage And Memory Loss In California Sea Lions

Posted: Dec 15 2015, 10:27am CST | by , in News | Latest Science News


Toxic Algae Causing Brain Damage and Memory Loss in California Sea Lions
Photo Credit: Getty Images

Deficits in spatial memory will make it difficult for sea lions to find food for themselves and survive in the wild.

Sea lions stranded on California beaches are facing huge trouble. 

According to a new study, a toxin produced by marine algae is causing deadly brain damage in sea lions. It may lead to memory loss and make it difficult for them to find their food and survive in the wild.

Toxic domoic acid appears naturally in spring, but the frequency and severity of the algal blooms have increased significantly in recent years due to environmental change and human impacts on the marine system.

For the study, researchers took brain scans and behavioral tests of sea lions that washed up on the west coast shores and found that hundreds of them had symptoms of domoic acid poisoning including disruption in brain networks, loss of sense of direction (disorientation) and seizures. 

Chronic exposure to the toxin mostly damaged the hippocampus, a part of brain which is linked to memory. "In this study, we were able to correlate the extent of hippocampal damage to specific behavioral impairments relevant to the animals' survival in the wild.” Team leader Peter Cook from University of California, Santa Cruz said.

To assess memory loss in sea lions, researchers adapted behavioral tests and then used MRI scans to see the extent of structural damages in the brains of affected sea lions, especially in the hippocampus. Animals with damage to the hippocampus performed poorly in long and short term memory related tasks.  In the scanners, researchers could see structural differences in the brains of sea lions.

"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.” Cook said.

Still researchers are not sure how heavy and how often exposure to the algan toxic is to cause this kind of brain damage. 

California sea lions have been washing up on the beaches since 2013 and researchers suggest that not only sea lions but dolphins, fur seals and sea otters might also have been affected. But the problem is unlikely to go away as warming ocean waters and agricultural runoff are causing algal outbreaks.

Peter Cook says.“The blooms are just going to get bigger and bigger. Sea lions are just tip of the iceberg.”

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Hira Bashir covers daily affairs around the world.




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