Domoic acid in phytoplankton and fish in San Diego, CA, USA

We provide the first confirmation of the presence of domoic acid (DA) in phytoplankton and fish in San Diego, California, based on samples collected between 1 October 2003 and 29 September 2004. In February 2004, we detected DA in seawater samples collected off the Scripps Pier and also in coastal samples as far as 120km to the north. At the same time we observed populations of toxic Pseudo-nitzschia australis and Pseudo-nitzschia multiseries as high as 7.7×104 cellsl−1. Elevated concentrations of DA and abundances of the toxic species were also found further north in coastal waters of Orange County and, to a lesser extent, in southern Los Angeles County. DA concentrations in the viscera from four species of fish obtained at or near the Scripps Pier ranged from low to above the critical level for public safety. Samples of mussel tissues from the Scripps Pier analyzed by the State Department of Health Services contained low but detectable amounts of DA. Concomitant sea lion strandings from San Diego to Malibu Beach may be related to the presence of DA. DA in tissue from mussels and fish provides evidence for the local transfer of DA from an algal source to higher trophic levels in San Diego coastal waters.