Species, tissue and gender-related organochlorine bioaccumulation in white-sided dolphins, pilot whales and their common prey in the Northwest Atlantic

Organochlorine concentrations were measured in white-sided dolphins, pilot whales, and their prey from the Gulf of Maine and used to identify species, tissue, and gender differences, and trophic transfer trends, in bioaccumul ation. Polychlorinated biphenyl concentrations ([PCB]) in dolphin blubber ( 13 +/- 7.1 mug/g fresh wt.) were twice those in pilot whales, but pesticide concentrations (20 +/- 13 mug/g fresh) were similar between species. 4,4'- DDE, trans-non-achlor, Cl-6(153) and Cl-6(138) concentrations were highest. Skin tissues had more recalcitrant organochlorines than the internal organ s. Male dolphins bioaccumulated higher concentrations of nonmetabolizable P CBs and hexachlorocyclohexane (HCH) isomers, whereas pilot whales had no ge nder-related differences in bioaccumulation. Pilot whales, mackerel, and he rring had proportionately higher concentrations of DDTs, whereas [PCB] were higher in dolphins and squid. Although these odontocetes feed at the same trophic level and store a similar suite of contaminants, dolphins bioaccumu lated higher and potentially hazardous 4,4'-DDE and PCB concentrations from food in their more geographically restricted range. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.