Polychlorinated biphenyls in harbor porpoises Phocoena phocoena (L.) from the Bay of Fundy, Canada and adjacent waters, with some information on chlordane and hexachlorobenzene levels.

Abstract

Polychlorinated biphenyl (PCBs) levels were measured in tissues from harbor porpoises collected during 1971–77 from the Bay of Fundy (Canada) and adjacent waters. Levels of chlordanes and hexachlorobenzene (HCB) were measured in smaller numbers of the same series of specimens from 1975–77. PCB levels were relatively high in all tissues of sexually immature specimens of both sexes as well as adult males, and relatively low in adult females. The maximum level in blubber was 310 ppm; in other tissues, commensurate with their lower fat content, maxima were rarely more than 2 ppm. PCB levels in blubber, liver, and kidney were correlated with one another. No discernible changes in mean levels between 1971–77 were detected, nor were significant regional differences recognized within the Bay of Fundy, or among specimens obtained between Newfoundland and Rhode Island. Levels increased significantly with age in all tissues from males, and decreased significantly in most tissues from females; individual variation was large. Particularly high levels in four-year old males and three-year old females were related to a growth spurt at puberty with correspondingly elevated food (and hence PCB) intake per unit of time. Chlordanes were present in most tissues, with a maximum of 14 ppm in blubber. Only small quantities (0.12 to 0.43 ppm) of HCB were recorded; the maximum was only 0.43 ppm in blubber, but levels of HCB were strongly correlated with respective PCB levels in the same tissues.