Control of Toxic Chemicals in Puget Sound Phase 3: Persistent Bioaccumulative and Toxic Contaminants in Pelagic Marine Fish Species from Puget Sound

This study is an assessment of selected persistent bioaccumulative toxic contaminants (PBTs) in a guild of mid-trophic-level pelagic fish predators in Puget Sound. It is part of a consortium of efforts aimed at identifying contaminants of concern in Puget Sound biota, where and how such contaminants enter the food chain, what processes transport toxics to the Sound, and the fate and transport of PBTs once there. We observed patterns of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) in Pacific hake (Merluccius productus ) and walleye pollock (Theragra chalcogramma) that are consistent with other pelagic species such as Pacific herring and Pacific salmon species that have been evaluated in previous studies. PCB, PBDE, and OCPs were all observed in a gradient of concentration, from high in Puget Sound basins that have experienced extensive development, to low in basins where watershed have been less developed. Some pesticides appeared to occur in greater abundance in one Developed Basin (Whidbey Basin) in which extensive development has been in the form of agriculture. PCB congener patterns in hake were consistent with focused, point sources of PCBs that have migrated throughout the ecosystem from urbanized areas over a long period. PBDE congeners and most OCP component patterns were more consistent with ubiquitous, similar terrestrial sources that differed only in magnitude (i.e. congener or compound patterns were similar across regions, but total concentrations were greater in developed regions). Pacific hake and walleye pollock represent a potential source of PBTs to their predators, including other fish predators, marine mammals, birds and humans. Hake exhibited lower PCB concentration than Pacific herring and resident Chinook salmon based on a comparison of contaminant wet weights, however, PCB lipid weights in hake were roughly equivalent to herring, and greater than resident Chinook salmon.