Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic
Date
2015
Authors
Scheuhammer, Anton
Braune, Brigit
Chan, Hing Man
Frouin, Héloïse
Krey, Anke
Letcher, Robert
Loseto, Lisa
Noël, Marie
Ostertag, Sonja
Ross, Peter
Journal Title
Journal ISSN
Volume Title
Publisher
Science of the Total Environment
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.
Description
Keywords
Canadian Arctic, Mercury, Biological effects, Fish, Marine mammals, Seabirds
Citation
Scheuhammer, A., Braune, B., Chan, H.M., Frouin, H., Krey, A., Letcher, R. & Wayland, M. (2015). Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic. Science of the Total Environment, 509-510, 91-103. http://dx.doi.org/10.1016/j.scitotenv.2014.05.142