STATES CHRONICLE – Not all of us are lucky enough to pretend to be marine biologists when an aquatic mammal drifts ashore. Most of us are stuck wondering why the animal would do that, or might even try to help the poor beast. Recently, scientists figured out the answer to why some of the animals drift ashore, more specifically the reason for sea lions get stranded due to brain damage caused by toxic algae.
Hundreds of sea lions get stranded ashore each year in California, and scientists have been baffled as to why for years. Now, a new study finally showed who the real culprit was.
The domoic acid, found in a species of microscopic algae, was found to cause permanent brain damage to the sea mammals, as well as some species of crabs.
One-time exposure is not really that dangerous, but when we’re talking about constant exposure, as is the case with the sea creatures, the domoic acid causes long-term brain damage that affects not only spatial memory, as the scientists believed up until now, but also disruption in brain networks, disorientation, and even seizures.
The research, led by Peter Cook and Charan Ranganath of the Dynamic Memory Laboratory at the UC Davis Center for Neuroscience, took MRIs of the brains of 30 sea lions under the care of the Marine Mammal Center in Sausalito.
The purpose was to find out the level of brain damage and lesions suffered by the mammals after being in contact with the toxic algae.
The scientists found that the part of the brain most affected by the domoic acid was the hippocampus, the part of the brain connected to memory.
However, even more worrisome, is the fact that the brain operations affected were not only those that took place in the hippocampus, but also those that involved interactions between the hippocampus and other unaffected brain structures.
The animals are usually affected by the toxin in the microscopic algae when the algae are in bloom, but extensive exposure can lead to brain damage over time.
Not only that, but the algae appear to have started blooming out of season, causing harm not only to the sea mammals, but also to the crab population.
Scientists believe the strange behavior of the algae to be caused by factors such as climate change and human interaction.
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