State-wide fish tissue contaminants survey and effects of feeding type, season and gender on fish tissue contamination levels.

摘要

Fish tissue fillets from benthic, predator, and mixed diet species were collected from 24 different watersheds in West Virginia. Composite samples were prepared from three to six fish fillets collected at each site, and concentrations of the chemical contaminants polychlorinated biphenyls (PCBs) and mercury were determined for each composite sample. Differences in contaminant concentrations among three major categories of feeding type (predator, benthic, and mixed diet) were examined. Differences due to species of fish and among watersheds were also examined. Predators had significantly higher mercury concentrations than benthic or mixed diet feeders and benthic feeding fish had significantly higher PCB concentrations than predator fish, with no significant differences of PCBs in mixed diet fish. Species-specific analysis showed that walleye contained the highest concentration of mercury and bluegill contained the highest concentration of PCBs. The Shenandoah watershed had the highest levels of PCBs and mercury and the lower New River watershed had the lowest concentrations of PCBs; channel catfish obtained from a NC hatchery and subsequently released into WV waters contained the lowest concentration of mercury. Channel catfish and carp were sampled during May, July, and November from the Monongahela River, Morgantown, WV, to determine if seasonal differences in concentrations of PCBs occurred within the fillet, liver and gonadal tissues. In addition, gender of each fish was identified and differences in concentrations of PCBs due to gender were examined. Fillets for channel catfish and livers in carp were the only tissue that showed significant differences. For channel catfish fillets, May contained the highest concentrations of PCBs and November had the lowest concentrations of PCBs; neither was different in the July collection. For carp livers, November contained the highest level of PCBs and May the lowest with no differences in the July sample. No gender differences were observed for any tissue or species.