domoic acid in the santa cruz wharf fishery

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State University, Monterey Bay and V. Welborn, University of California, Santa Cruz, .... H. Landsberg, C. R. Tomas and G. A. Vargo (Eds) Harmful Algae 2002. ... Wekell, J. C., E. J. Gauglitz, H. J. Barnett, C. L. Hatfield, D. Simons, and D. Ayres.

CALIFORNIA FISH AND GAME California Fish and Game 91(3):179-192

2005

DOMOIC ACID IN THE SANTA CRUZ WHARF FISHERY SPENCER E. FIRE1 Ocean Sciences Department University of California at Santa Cruz Santa Cruz, CA 95064 E-mail: [email protected] MARY W. SILVER Institute of Marine Sciences University of California at Santa Cruz Santa Cruz, CA 95064

ABSTRACT Fish caught from piers are an important part of the recreational fishery and are not routinely monitored for phycotoxins. Species taken in this catch are often different from those obtained in the commercial catch further offshore, and diets of pier-caught fish may differ from those of offshore species, resulting in different toxin exposure. Here we report preliminary results from a study on diatom toxins in the recreational fish catch, using data collected from 4 July 2001 to 15 December 2001 at the Santa Cruz Municipal Wharf, a heavily fished coastal pier in California. A variety of frequently caught fish species were taken by hook-and-line from the Santa Cruz Wharf and tested for the diatom toxin domoic acid (DA). Fish viscera and muscle tissue were analyzed separately using High Performance Liquid Chromatography methods. DA was detected in fish viscera but not in fish muscle tissue. DA in fish viscera coincided with the appearance of elevated cell counts of species of the DA-producing diatom, Pseudo-nitzschia australis, and with DA in the water column. DA was detected almost exclusively in white croaker, Genyonemus lineatus, and to a lesser extent in staghorn sculpin, Leptocottus armatus. Although the DA levels in these two fish species were comparatively low (