1998 Domoic Acid Outbreak

• May/June--Domoic Acid implicated in deaths of sea lions in Central California

• June--Sampling program begun with Quileute Natural Resources staff

• July--Domoic Acid detected on Washington Coast

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5. 1998 DOMOIC ACID OUTBREAK

-MAY—Sick sea lions in C. Calif.-Reports of them being disoriented and wandering up onto roads- Exhibited many symptoms mentioned earlier-Pseudos found in fish in the guts of the animal

-Program w/Quileutes begun-JULY—DA detected in Razors on WA coast

In May and June of 1998, sea lions were observed hauling out of the water along the southern and central California coast with strange and unusual behavior—there were reports of the mammals appearing disorientated and wandering onto roads and highways. Some of the symptoms were similar to those observed in 1991 among domoic acid poisoned birds. Additionally, waters off the southern and central California coast, appeared to have a heavy bloom of algae, later identified as Pseudo-nitzschia. Some form of intoxication was suspected based on these observations. The suffering animals were taken to various centers for observation and tests to determine the cause of this behavior. Among the various tests run, domoic acid was detected in the urine of sea lions with the most pronounced symptoms. Stomach contents were identified to contain anchovies and the contents also tested positive for domoic acid. Samples of both anchovies and sardines from the area were tested and domoic acid was detected in these fish. In addition, Pseudo-nitzschia cell remnants were detected in the stomachs of these fish.

Because of our earlier experience in 1991 with domoic acid along the west coast of North America, it was considered a strong possibility that if events unfolded as before, we would begin seeing domoic acid in shellfish on Washington State beaches. Earlier in 1998, we began the process of setting up a monitoring program for some ocean beaches working with the Quileute tribe in Washington state. This outbreak gave us an impetus to begin this monitoring process in June and July of 1998. In July domoic acid began showing increases in razor clams in both Oregon and Washington state.