Brent Kearney

In a previous article, I introduced the L.A. Times special report, Altered Oceans. The second part of the special report explores a consequence of the extreme algae growth that seems to be taking over the oceans: marine mammals are succumbing to domoic acid poisoning. The new algae that has appeared on the west coast of the U.S. produces domoic acid, and it has made its way into the food chain.

Sea lions have been called the “sentinels of ocean and human health” — if there is something wrong with them, then there is something wrong with the ocean, and if there is something wrong with the ocean, we have a problem too. Sea lions have been found in odd places, disoriented and behaving strangely, some of them going into seizures. The Marine Mammal Care Center at Ft. MacAurthur in San Pedro has been overflowing with them.

The problem turns out to be that domoic acid causes neurological damage: it kills cells in the hippocampus, an area of the brain responsible for short-term and spacial memory. Damage to this area impairs the ability to navigate. Thus, the reason they are turning up disoriented in strange places. More extensive damage apparently induces seizures and other serious health problems, as many of the sea lions must be euthanized, failing a response to treatment procedures.

Studies of clams along the same shores show high levels of domoic acid as well. Unfortunately the clams are a main part of the diet of a local Native American tribe, and harvested by thousands of others. Sea lions are fairly high level mammals, like us, and if they are getting poisioned from eating the fish in the ocean, then we probably are as well.