Monitoring toxin uptake in edible fish tissues from Pfiesteria containing waters

Pfiesteria piscicida, a dinoflagellate first identified in 1988, has been implicated as a causative agent in major fish kills in estuaries of NC and the southeastern United States. A tissue culture assay for the detection and characterization of this toxin(s) has been adapted from standard in vitro bioassays. Using this assay, tissue samples taken from live fish caught during a fish kill were analyzed for the presence of toxin. No apparent effect on cell viability was observed using extracts from croaker, spot, striped mullet, mackerel or perch. Only those extracts of muscle tissue from Atlantic menhaden showed a significant effect in the bioassay. During the summer of 1998, a biweekly monitoring of tissue extracts of bluefish, croaker, pigfish, pinfish, spot, silver perch, southern flounder, summer flounder, weakfish, bay anchovy and menhaden was carried out. Data indicate that only tissue extracts from menhaden containing visible lesions showed a significant effect on the viability of cells in culture.