title: Mercury in the marine environment of the Canadian Arctic: review of recent findings.
abstract: This review summarizes data and information which have been generated on mercury (Hg) in the marine environment of the Canadian Arctic since the previous Canadian Arctic Contaminants Assessment Report (CACAR) was released in 2003. Much new information has been collected on Hg concentrations in marine water, snow and ice in the Canadian Arctic. The first measurements of methylation rates in Arctic seawater indicate that the water column is an important site for Hg methylation. Arctic marine waters were also found to be a substantial source of gaseous Hg to the atmosphere during the ice-free season. High Hg concentrations have been found in marine snow as a result of deposition following atmospheric mercury depletion events, although much of this Hg is photoreduced and re-emitted back to the atmosphere. The most extensive sampling of marine sediments in the Canadian Arctic was carried out in Hudson Bay where sediment total Hg (THg) concentrations were low compared with other marine regions in the circumpolar Arctic. Mass balance models have been developed to provide quantitative estimates of THg fluxes into and out of the Arctic Ocean and Hudson Bay. Several recent studies on Hg biomagnification have improved our understanding of trophic transfer of Hg through marine food webs. Over the past several decades, Hg concentrations have increased in some marine biota, while other populations showed no temporal change. Marine biota also exhibited considerable geographic variation in Hg concentrations with ringed seals, beluga and polar bears from the Beaufort Sea region having higher Hg concentrations compared with other parts of the Canadian Arctic. The drivers of these variable patterns of Hg bioaccumulation, both regionally and temporally, within the Canadian Arctic remain unclear. Further research is needed to identify the underlying processes including the interplay between biogeochemical and food web processes and climate change.
authors: Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, Canada K1A 0H3. Electronic address: birgit.braune@ec.gc.ca.
authors: Birgit
authors: B
authors: Braune
authors: Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, Canada K1A 0H3.
authors: John
authors: J
authors: Chételat
authors: Département de sciences biologiques, Université de Montréal, CP 6128, Succ. Centre-Ville Pavillon Marie-Victorin, Montreal, Quebec, Canada H3C 3 J7.
authors: Marc
authors: M
authors: Amyot
authors: Fisheries and Oceans Canada, Institute of Ocean Sciences, 9860 West Saanich Road, PO Box 6000, Sidney, British Columbia, Canada V8L 4B2; Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, Ontario, Canada K7K 7B4.
authors: Tanya
authors: T
authors: Brown
authors: Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5.
authors: Meredith
authors: M
authors: Clayden
authors: Environment Canada, National Water Research Institute, 11 Innovation Blvd., Saskatoon, Saskatchewan, Canada S7N 3H5.
authors: Marlene
authors: M
authors: Evans
authors: Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario, Canada N9B 3P4.
authors: Aaron
authors: A
authors: Fisk
authors: Centre for Earth Observation Science, 497 Wallace Bldg., University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
authors: Ashley
authors: A
authors: Gaden
authors: Département de sciences biologiques, Université de Montréal, CP 6128, Succ. Centre-Ville Pavillon Marie-Victorin, Montreal, Quebec, Canada H3C 3 J7.
authors: Catherine
authors: C
authors: Girard
authors: Centre for Earth Observation Science, 497 Wallace Bldg., University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
authors: Alex
authors: A
authors: Hare
authors: Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario, Canada L7R 4A6.
authors: Jane
authors: J
authors: Kirk
authors: Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9.
authors: Igor
authors: I
authors: Lehnherr
authors: Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, Canada K1A 0H3.
authors: Robert
authors: R
authors: Letcher
authors: Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6.
authors: Lisa
authors: L
authors: Loseto
authors: Fisheries and Oceans Canada, Institute of Ocean Sciences, 9860 West Saanich Road, PO Box 6000, Sidney, British Columbia, Canada V8L 4B2.
authors: Robie
authors: R
authors: Macdonald
authors: Department of Environmental Science, Acadia University, Wolfville, Nova Scotia, Canada B4P 2R6.
authors: Erin
authors: E
authors: Mann
authors: Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario, Canada N9B 3P4.
authors: Bailey
authors: B
authors: McMeans
authors: Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario, Canada L7R 4A6.
authors: Derek
authors: D
authors: Muir
authors: Department of Environmental Science, Acadia University, Wolfville, Nova Scotia, Canada B4P 2R6.
authors: Nelson
authors: N
authors: O'Driscoll
authors: Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada K1N 6N5.
authors: Alexandre
authors: A
authors: Poulain
authors: Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, Ontario, Canada K7K 7B4.
authors: Ken
authors: K
authors: Reimer
authors: Centre for Earth Observation Science, 497 Wallace Bldg., University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2; Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6.
authors: Gary
authors: G
authors: Stern
mesh_terms: D001110:Arctic Regions; D002170:Canada; D004784:Environmental Monitoring; D008628:Mercury / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Biogeochemical processes; Canadian Arctic; Food webs; Marine environment; Mercury; Temporal trends