Harbor seals (Phoca vitulina) in British Columbia, Canada, and Washington State, USA, reveal a combination of local and global polychlorinated biphenyl, dioxin, and furan signals

The harbor seal (Phoca vitulina) can serve as a useful indicator of food web contamination by persistent organic pollutants (POPs) because of its high trophic level, wide distribution in temperate coastal waters of the Northern Hemisphere, and relative ease of capture. In 1996 through 1997, we live‐captured 60 harbor seal pups from three regions, spanning remote (Queen Charlotte Strait, BC, Canada), moderately industrialized (Strait of Georgia, BC, Canada), and heavily industrialized (Puget Sound, WA, USA) marine basins straddling the Canada‐United States border. Biopsy samples of blubber were taken and analyzed for congener‐specific polychlorinated biphenyls (PCBs), polychlorinated dibenzo‐p‐dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) by using high‐resolution gas chromatography‐high‐resolution mass spectrometry. Harbor seals in Puget Sound were heavily contaminated with PCBs, whereas seals from the Strait of Georgia had relatively high concentrations of PCDDs and PCDFs. Pattern evaluation and principal components analysis suggested that proximity to sources influenced the mixture to which seals were exposed, with those inhabiting more remote areas being exposed to lighter PCB congeners (those with lower Henry's law constant and KOW) that disperse more readily through atmospheric and other processes. Total toxic equivalents to 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin for the PCBs, PCDDs, and PCDFs suggest that Puget Sound seals are at greatest risk for adverse health effects, and that PCBs represent the class of dioxinlike contaminants of greatest concern at all sites.

[1]  P. Ross,et al.  GROWTH AND DEVELOPMENT IN FREE‐RANGING HARBOR SEAL (PHOCA VITULINA) PUPS FROM SOUTHERN BRITISH COLUMBIA, CANADA , 2002 .

[2]  M. Ikonomou,et al.  Assessment of chlorinated dibenzo-p-dioxin and dibenzofuran trends in sediment and crab hepatopancreas from pulp mill and harbor sites using multivariate- and index-based approaches. , 2002, Environmental science & technology.

[3]  W. Cretney,et al.  Bioavailability of chlorinated dibenzo‐p ‐dioxins and dibenzofurans to dungeness crab (Cancer magister) at marine pulp mill sites in British Columbia, Canada , 2000 .

[4]  P. Ross,et al.  Contaminant‐related disruption of vitamin a dynamics in free‐ranging harbor seal (Phoca vitulina) pups from british columbia, canada, and washington state, usa , 2000 .

[5]  L. Barrie,et al.  Trans-Pacific Air Pollution , 2000, Science.

[6]  L. Barrett‐Lennard,et al.  High PCB Concentrations in Free-Ranging Pacific Killer Whales, Orcinus orca: Effects of Age, Sex and Dietary Preference , 2000 .

[7]  D. Schindler,et al.  Organochlorine transfer in the food web of subalpine Bow Lake, Banff National Park , 2000 .

[8]  R. Dietz,et al.  Circumpolar trends of PCBs and organochlorine pesticides in the arctic marine environment inferred from levels in ringed seals , 2000 .

[9]  P. Ross.  Marine Mammals as Sentinels in Ecological Risk Assessment , 2000 .

[10]  K. Reimer,et al.  Spatial and temporal trends and effects of contaminants in the Canadian Arctic marine ecosystem: a review. , 1999, The Science of the total environment.

[11]  F. Gobas,et al.  Role of chemical and ecological factors in trophic transfer of organic chemicals in aquatic food webs , 1999 .

[12]  Safe,et al.  Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. , 1998, Environmental health perspectives.

[13]  R. Witkamp,et al.  Congener specific PCB and polychlorinated camphene (toxaphene) levels in Svalbard ringed seals (Phoca hispida) in relation to sex, age, condition and cytochrome P450 enzyme activity. , 1998, The Science of the total environment.

[14]  B. Bonn.  Polychlorinated dibenzo-p-dioxin and dibenzofuran concentration profiles in sediment and fish tissue of the Willamette Basin, Oregon , 1998 .

[15]  L. Barrie,et al.  Polychlorinated biphenyls in Arctic air. 1. Temporal and spatial trends : 1992-1994 , 1997 .

[16]  P. Leonards,et al.  Concentration-Dependent Changes of PCB Patterns in Fish-Eating Mammals: Structural Evidence for Induction of Cytochrome P450 , 1997, Archives of environmental contamination and toxicology.

[17]  W. Jarman,et al.  Organochlorines in sea otters and bald eagles from the Aleutian Archipelago , 1997 .

[18]  J. Giesy,et al.  PCBS, DDE, DDT, and TCDD‐EQ in two species of albatross on Sand Island, Midway Atoll, North Pacific Ocean , 1997 .

[19]  S. C. Samis,et al.  Environmental response to decreased dioxin and furan loadings from British Columbia coastal pulp mills , 1997 .

[20]  R. Norstrom,et al.  Patterns, trends, and toxicological significance of chlorinated hydrocarbon and mercury contaminants in bald eagle eggs from the pacific coast of Canada, 1990–1994 , 1996, Archives of environmental contamination and toxicology.

[21]  H. van Loveren,et al.  Contaminant-induced immunotoxicity in harbour seals: wildlife at risk? , 1996, Toxicology.

[22]  A. Osterhaus,et al.  Impaired immunity in harbour seals (Phoca vitulina) exposed to bioaccumulated environmental contaminants: review of a long-term feeding study. , 1996, Environmental health perspectives.

[23]  Paul V. Roberts,et al.  A critical review of Henry's law constants for environmental applications , 1996 .

[24]  H. van Loveren,et al.  Short term fasting does not aggravate immunosuppression in harbour seals (Phoca vitulina) with high body burdens of organochlorines. , 1995, Chemosphere.

[25]  D. Hawker.  Vapor pressures and Henry's law constants of polychlorinated biphenyls , 1989 .

[26]  Des Connell,et al.  Octanol-water partition coefficients of polychlorinated biphenyl congeners , 1988 .

[27]  S. Tanabe,et al.  Capacity and mode of PCB metabolism in small cetaceans , 1988 .

[28]  R. Addison,et al.  Transfer of Organochlorine Residues from Blubber through the Circulatory System to Milk in the Lactating Grey Seal Halichoerus grypus , 1987 .

[29]  John Aitchison,et al.  The Statistical Analysis of Compositional Data , 1986 .

[30]  W. Shiu,et al.  A Critical Review of Aqueous Solubilities, Vapor Pressures, Henry’s Law Constants, and Octanol–Water Partition Coefficients of the Polychlorinated Biphenyls , 1986 .

[31]  W. E. Ricker,et al.  Computation and uses of central trend lines , 1984 .

[32]  John Calambokidis,et al.  Trends and status of harbor seals in Washington State: 1978-1999 , 2003 .

[33]  S. O'Neill,et al.  TOXIC CONTAMINANTS IN MARINE AND ANADROMOUS FISHES FROM PUGET SOUND, WASHINGTON , 2001 .

[34]  C. Henny,et al.  Contaminants in Ospreys from the Pacific Northwest: II. Organochlorine Pesticides, Polychlorinated Biphenyls, and Mercury, 1991–1997 , 2000, Archives of environmental contamination and toxicology.

[35]  P. Olesiuk.  An assessment of the status of harbour seals (Phoca vitulina) in British Columbia , 1999 .

[36]  R. Addison,et al.  Trends in Organochlorine Residue Concentrations in Ringed Seal (Phoca hispida) from Holman, Northwest Territories, 1972 - 91 , 1998 .

[37]  P. Larsson,et al.  Biotransport of organic pollutants to an inland Alaska Lake by migrating Sockeye Salmon (Oncorhynchus nerka) , 1998 .

[38]  F. Wania.  Global fractionation and cold condensation of low volatility organochlorine compounds in polar regions , 1993 .

[39]  R. Addison,et al.  Organochlorine Residue Levels in Arctic Ringed Seals: Variation with Age and Sex , 1974 .