Monitoring Approaches for Early Warning of Domoic Acid Events in Washington State

n the U.S. west coast, blooms of the potentially toxic diatom Pseudo-nitzschia can cause amnesic shellfi sh poisoning (ASP), resulting in economic impacts to coastal economies and public health concerns.The transfer of toxin, via fi lter feeding of Pseudonitzschia or ingestion of fi lter feeding organisms, to shellfi sh, crustaceans, seabirds, fi nfi sh, and marine mammals has led to mortalities of brown pelicans, Brandt's cormorants, and sea lions.A unique problem on the outer coast of the Olympic peninsula in Washington State, is that the Pacifi c razor clam, Siliqua patula (Figure 1), can retain high concentrations of the algal toxin, domoic acid (DA), for over one year (Wekell et al., 1994;Adams et al., 2000).During toxic events, recreational, commercial, and tribal subsistence harvest of clams, valued at over $20 million annually (Anderson, 1995), is suspended and public health is threatened.