Properties of blood, porphyrins, and exposure to legacy and emerging persistent organic pollutants in surf scoters (Melanitta perspicillata) overwintering on the south coast of British Columbia, Canada.
The surf scoter (Melanitta perspicillata) is a little-studied species of North American sea duck. Estimates suggest it has experienced a precipitous decline in breeding numbers over the latter half of the past century. To investigate the potential role of contaminant uptake and toxicity in the population decline, this study undertook to measure blood chemistry, porphyrin concentrations, EROD, and organic contaminants in mature surf scoters wintering in the Strait of Georgia, BC, Canada. Hepatic organochlorine pesticide, polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran, polychlorinated biphenyl (PCB), polybrominated diphenyl ether, and nonylphenol concentrations were relatively low; for example, SigmaTEQs (toxic equivalents) for PCBs, dioxins, and furans combined ranged from 4.7 ng/kg wet weight in reference-site (Baynes Sound) birds to 11.4 ng/kg wet weight in birds from Vancouver Harbour. Nonetheless, elevated EROD activity indicated that birds in Howe Sound were responding to an Ah-receptor-mediated stressor, which was also affecting hematocrit values and possibly vitamin A status. In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition. The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern. Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound.
Wilson
L K
LK
Canadian Wildlife Service, Pacific Wildlife Research Centre, Environment Canada, 5421 Robertson Rd., RR1, Delta, BC, V4K 3N2, Canada.
Harris
M L
ML
Trudeau
S
S
Ikonomou
M G
MG
Elliott
J E
JE
D000818:Animals; D001572:Benzofurans / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001955:British Columbia; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D000072338:Dibenzofurans, Polychlorinated; D004372:Ducks / Q000097:blood / Q000378:metabolism*; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring; D005260:Female; D055768:Halogenated Diphenyl Ethers / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D006843:Hydrocarbons, Chlorinated / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D009930:Organic Chemicals / Q000097:blood / Q000378:metabolism* / Q000633:toxicity; D010575:Pesticides / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D010636:Phenols / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D011166:Porphyrins / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000097:blood / Q000378:metabolism* / Q000633:toxicity
D001572:Benzofurans; D015415:Biomarkers; D000072338:Dibenzofurans, Polychlorinated; D055768:Halogenated Diphenyl Ethers; D006843:Hydrocarbons, Chlorinated; D009930:Organic Chemicals; D010575:Pesticides; D010636:Phenols; D000072317:Polychlorinated Dibenzodioxins; D011166:Porphyrins; D014874:Water Pollutants, Chemical; C025256:nonylphenol; D011078:Polychlorinated Biphenyls; D019363:Cytochrome P-450 CYP1A1