POLYCHLORINATED BIPHENYL CONGENER DISTRIBUTIONS IN WINTER FLOUNDER AS RELATED TO GENDER, SPAWNING SITE, AND CONGENER METABOLISM

Concentrations of 17 polychlorinated biphenyl (PCB) congeners were measured in liver of gonadally mature winter flounder collected from Fox Island and Gaspee Point, RI, and from New Bedford Harbor, MA. These locations represent spawning sites with different degrees and sources of PCB contamination. The data demonstrate that the PCB concentrations and patterns in these fish reflect those of their spawning grounds, indicating that winter flounder caught in clean offshore waters could have substantial amounts of tissue PCB, that the content of PCB congeners in winter flounder liver is influenced little by sex or reproductive condition, and that flounder selectively metabolize PCB congeners with adjacent meta,para-unsubstituted carbon atoms. Based on congener concentrations and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalency factors, the non-ortho congeners, 77, 126, and 169, contributed more to the potential (mammalian) toxicity of PCB in flounder than more abundant, but less toxic, non-coplanar congeners.