Evidence of weak contaminant-related oxidative stress in glaucous gulls (Larus hyperboreus) from the Canadian Arctic.
Environmental contaminants are transported over great distances to Arctic ecosystems, where they can accumulate in wildlife. Whether contaminant concentrations in wildlife are sufficient to produce adverse effects remains poorly understood. Exposure to contaminants elevates oxidative stress with possible fitness consequences. The glaucous gull (Larus hyperboreus), an Arctic top predator, was used as a bioindicator for investigating relationships between contaminant levels (organochlorines and polychlorinated biphenyls [OC/PCB], mercury [Hg], and selenium [Se]) and measures of oxidative stress (glutathione [GSH] metabolism and lipid peroxidation) in Canadian Arctic ecosystems. Contaminant levels were low and associations between contaminant exposure and oxidative stress were weak. Nevertheless, glutathione peroxidase activity rose with increasing hepatic Se concentrations, levels of thiols declined as Hg and OC/PCB levels rose, and at one of the two study sites levels of lipid peroxidation were elevated with increasing levels of hepatic Hg. These results suggest the possibility of a deleterious effect of exposure to contaminants on gull physiology even at low contaminant exposures.
Wayland
Mark
M
Environment Canada, Prairie & Northern Wildlife Research Centre, 115 Perimeter Rd., Saskatoon, SK, S7N 0X4, Canada. mark.wayland@ec.gc.ca
Hoffman
David J
DJ
Mallory
Mark L
ML
Alisauskas
Ray T
RT
Stebbins
Katherine R
KR
D000818:Animals; D001110:Arctic Regions; D002170:Canada; D046091:Charadriiformes / Q000502:physiology*; D004785:Environmental Pollutants / Q000633:toxicity*; D005978:Glutathione / Q000378:metabolism; D006843:Hydrocarbons, Chlorinated / Q000633:toxicity; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D008628:Mercury / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D012643:Selenium / Q000633:toxicity
D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D011078:Polychlorinated Biphenyls; D008628:Mercury; D005978:Glutathione; D012643:Selenium