Dear Colleagues: The following paper is now available at http://www.int-res.com/abstracts/meps/v368/ Fire SE, Flewelling LJ, Naar J, Twiner MJ, Henry MS, Pierce RH, Gannon DP, Wang Z, Davidson L, Wells RS (2008). PREVALENCE OF BREVETOXINS IN PREY FISH OF BOTTLENOSE DOLPHINS IN SARASOTA BAY, FLORIDA. Marine Ecology Progress Series 368:283-294. ABSTRACT: Blooms of the brevetoxin-producing dinoflagellate Karenia brevis have been linked to high mortality of bottlenose dolphins Tursiops truncatus on Florida's Gulf of Mexico coast. A clear understanding of trophic transfer of brevetoxin from its algal source up the food web to top predators is needed to assess exposure of affected dolphin populations. Prey fish constitute a means of accumulating and transferring brevetoxins and are potential vectors of brevetoxin to dolphins frequently exposed to K. brevis blooms. Here we report results of brevetoxin analyses of the primary fish species consumed by long-term resident bottlenose dolphins inhabiting Sarasota Bay, Florida. Fish collected during K. brevis blooms in 2003 to 2006 were analyzed by competitive enzyme-linked immunosorbent assay (ELISA) and had brevetoxin concentrations ranging from 4 to 10 844 ng PbTx-3 eq g-1 tissue. Receptor binding assay (RBA) and liquid chromatography-mass spectrometry (LC-MS) analysis confirmed toxicity and the presence of parent brevetoxins and known metabolites. Fish collected in the absence of K. brevis blooms tested positive for brevetoxin by ELISA and RBA, with concentrations up to 1500 ng PbTx-3 eq g-1 tissue. These findings implicate prey fish exposed to K. brevis blooms as brevetoxin vectors for their dolphin predators and provide a critical analysis of persistent brevetoxin loads in the food web of dolphins repeatedly exposed to Florida red tides. For more information, please contact me at spencer.fire@noaa.gov Sincerely, Spencer E. Fire, Ph.D. Marine Biotoxins Program Center for Coastal Environmental Health and Biomolecular Research NOAA/National Ocean Service 219 Fort Johnson Road Charleston, SC 29412 Tel: 843.762.8574 Fax: 843.762.8700 Email: spencer.fire@noaa.gov