Polychlorinated biphenyls and chlorinated pesticides in harbor seals (<i>Phoca vitulina concolor</i>) from the northwestern Atlantic coast

TitlePolychlorinated biphenyls and chlorinated pesticides in harbor seals (Phoca vitulina concolor) from the northwestern Atlantic coast
Publication TypeJournal Article
Year of Publication2005
AuthorsShaw, SD, Brenner, D, Bourakovsky, A, Mahaffey, CA, Perkins, CR
JournalMarine Pollution Bulletin
Pagination1069 - 1084
Date Published2005/10/01/
ISBN Number0025-326X
KeywordsEpizootics, Harbor Seals, Northwestern Atlantic, Organochlorine pesticides, PCBs, Temporal trends

Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordane-related compounds (CHLs), mirex, hexachlorocyclohexane isomers (HCHs), dieldrin, and hexachlorobenzene (HCB) were determined in blubber of harbor seals (Phoca vitulina concolor) from the northwestern Atlantic coast. PCBs, DDTs, and CHLs were the major persistent organochlorines in harbor seal blubber, while mirex, HCHs, dieldrin, and HCB were minor contaminants. Highest concentrations were found in the adult males, followed by the pups, yearlings, adult females, and fetuses. DDT and PCB concentrations have declined from the high levels reported in the early 1970s, but no declines were observed in our samples over the ten-year period 1991–2001. DDT/PCB ratios were indicative of a more rapid decline of DDTs than PCBs, while ratios of p,p′-DDE/DDT were indicative of a metabolic “weathering” of DDT. The population appears to be susceptible to disease outbreaks, as evidenced by a recurrence of viral epizootics since the late 1970s. The PCB burdens in these seals are similar to levels reported in seals from polluted regions of Europe and Asia, and exceed the estimated threshold levels for adverse reproductive and immune system effects in the species.

Short TitleMarine Pollution Bulletin