title: Biological and chemical redox transformations of mercury in fresh and salt waters of the high arctic during spring and summer.
abstract: It is well-established that atmospheric deposition transports Hg to Arctic regions, but the postdepositional dynamics of Hg that can alter its impact on Arctic food chains are less understood. Through a series of in situ experiments, we investigated the redox transformations of Hg in coastal and inland aquatic systems. During spring and summer, Hg reduction in streams and pond waters decreased across a 4-fold increase in salinity. This alteration of Hg reduction due to chloride was counterbalanced by the presence of particles, which favored the conversion of oxidized Hg to its elemental form. In saline waters, biogenic organic materials, produced by algae, were able to promote oxidation of Hg(O) even under dark conditions. Overall these results point to the vulnerability of marine/ coastal Arctic systems to Hg, compared to inland systems, with oxidation processes enhancing Hg residence times and thus increasing its potential to enter the food chain.
authors.affiliation: Groupe de Recherche Inter-universitaire en limnologie (GRIL), Département des sciences biologiques, Université de Montréal, Succursale Centre-Ville, Pavillon Marie-Victorin, Montréal, Québec, Canada.
authors.forename: Alexandre J
authors.initials: AJ
authors.lastname: Poulain
authors.forename: Edenise
authors.initials: E
authors.lastname: Garcia
authors.forename: Marc
authors.initials: M
authors.lastname: Amyot
authors.forename: Peter G C
authors.initials: PG
authors.lastname: Campbell
authors.forename: Farhad
authors.initials: F
authors.lastname: Raofie
authors.forename: Parisa A
authors.initials: PA
authors.lastname: Ariya
mesh_terms: D001110:Arctic Regions; D001419:Bacteria / Q000378:metabolism; D002712:Chlorides / Q000032:analysis; D004785:Environmental Pollutants / Q000737:chemistry* / Q000378:metabolism; D056890:Eukaryota / Q000378:metabolism; D020387:Food Chain; D005618:Fresh Water / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D007501:Iron / Q000032:analysis; D008628:Mercury / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D012621:Seasons; D012623:Seawater / Q000737:chemistry*
chemical_list: D002712:Chlorides; D004785:Environmental Pollutants; D007501:Iron; D008628:Mercury