title: Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic.
abstract: This review summarizes our current state of knowledge regarding the potential biological effects of mercury (Hg) exposure on fish and wildlife in the Canadian Arctic. Although Hg in most freshwater fish from northern Canada was not sufficiently elevated to be of concern, a few lakes in the Northwest Territories and Nunavut contained fish of certain species (e.g. northern pike, Arctic char) whose muscle Hg concentrations exceeded an estimated threshold range (0.5-1.0 μg g(-1) wet weight) within which adverse biological effects begin to occur. Marine fish species generally had substantially lower Hg concentrations than freshwater fish; but the Greenland shark, a long-lived predatory species, had mean muscle Hg concentrations exceeding the threshold range for possible effects on health or reproduction. An examination of recent egg Hg concentrations for marine birds from the Canadian Arctic indicated that mean Hg concentration in ivory gulls from Seymour Island fell within the threshold range associated with adverse effects on reproduction in birds. Mercury concentrations in brain tissue of beluga whales and polar bears were generally lower than levels associated with neurotoxicity in mammals, but were sometimes high enough to cause subtle neurochemical changes that can precede overt neurotoxicity. Harbour seals from western Hudson Bay had elevated mean liver Hg concentrations along with comparatively high muscle Hg concentrations indicating potential health effects from methylmercury (MeHg) exposure on this subpopulation. Because current information is generally insufficient to determine with confidence whether Hg exposure is impacting the health of specific fish or wildlife populations in the Canadian Arctic, biological effects studies should comprise a major focus of future Hg research in the Canadian Arctic. Additionally, studies on cellular interactions between Hg and selenium (Se) are required to better account for potential protective effects of Se on Hg toxicity, especially in large predatory Arctic fish, birds, and mammals.
authors.affiliation: Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada.
authors.forename: Anton
authors.initials: A
authors.lastname: Scheuhammer
authors.affiliation: Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada. Electronic address: birgit.braune@ec.gc.ca.
authors.forename: Birgit
authors.initials: B
authors.lastname: Braune
authors.affiliation: Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors.forename: Hing Man
authors.initials: HM
authors.lastname: Chan
authors.affiliation: Jasco Research, 4464 Markam St., Victoria, BC V8Z 7X8, Canada.
authors.forename: Héloïse
authors.initials: H
authors.lastname: Frouin
authors.affiliation: Natural Resources and Environmental Studies, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada.
authors.forename: Anke
authors.initials: A
authors.lastname: Krey
authors.affiliation: Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Letcher
authors.affiliation: Fisheries and Oceans Canada, National Centre for Arctic Aquatic Research Excellence, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: Loseto
authors.affiliation: School of Earth and Ocean Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada.
authors.forename: Marie
authors.initials: M
authors.lastname: Noël
authors.affiliation: Natural Resources and Environmental Studies, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada.
authors.forename: Sonja
authors.initials: S
authors.lastname: Ostertag
authors.affiliation: Fisheries and Oceans Canada, Institute of Ocean Sciences, Sidney, BC V8L 4B2, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Ross
authors.affiliation: Environment Canada, Canadian Wildlife Service, 115 Perimeter Rd., Saskatoon, Saskatchewan S7N 0X4, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Wayland
mesh_terms: D000818:Animals; D001110:Arctic Regions; D002170:Canada; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000633:toxicity*; D005399:Fishes; D008628:Mercury / Q000633:toxicity*
chemical_list: D004785:Environmental Pollutants; D008628:Mercury
keywords: Biological effects; Canadian Arctic; Fish; Marine mammals; Mercury; Seabirds