Blood Concentrations of Some Persistent Organohalogens in Free-ranging Spotted Seals (Phoca largha) from Bristol Bay, Alaska

Abstract

In recent years, the relatively high levels of organochlorine contaminants and increasing levels of brominated flame retardants found in tissues of marine mammals have raised concerns that exposure to these marine pollutants may compromise individual health. In this pilot study, levels of 11 polychlorinated biphenyls, 3 polybrominated diphenyl ethers, and the DDT metabolitep,p′-diphenyldichloroethylene were analyzed in whole blood of 7 free-ranging spotted seals (Phoca largha) from Bristol Bay, Alaska, sampled during 2000 and 2001. Blood concentrations of analytes were generally low (<1 ppb wet weight). Open-ocean foraging and feeding on a lower trophic level may contribute to the relatively lower levels of organohalogens found in this species as compared to the closely related harbor seal, Phoca vitulina, occurring in Bristol Bay.

Thanks are due to E. Berg for laboratory assistance and to L. Jemison and K. Hastings for collection of seal blood samples in Bristol Bay. We appreciated insightful comments provided by K. Frost and L. Dehn. Funding support (to JCCN) included the Predoctoral Fellowship in Ecology (UCD), Jastro-Shields Research Grant (UCD), UC Marine Council Research Grant (02 T CEQI 03 0104), and NIEHS Traineeship in Environmental Toxicology (5 T32 ES07059-25).

Notes

Dehn, L.-A. 2005. Trophic relationships in an Arctic marine foodweb and implications for trace element dynamics. PhD thesis, Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks.

Neale, J. C. C. 2004. Persistent organic contaminants and contaminant-induced immune and health alterations in the harbor seal, Phoca vitulina, pp. 13–59. PhD thesis, University of California at Davis, Davis.