Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 6, 785-794, 2002
http://www.hydrol-earth-syst-sci.net/6/785/2002/
doi:10.5194/hess-6-785-2002
© Author(s) 2002. This work is licensed under the
Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.
 
31 Aug 2002
Controls on the fate and transport of methylmercury in a boreal headwater catchment, northwestern Ontario, Canada
B. A. Branfireun1 and N. T. Roulet2 1Department of Geography, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ontario, Canada L5L 1C6
2Department of Geography and Centre for Climate and Global Change Research, McGill University, 805 Sherbrooke Street West, Montréal, Québec, Canada H3A 2K6
Email for corresponding author: brian.branfireun@utoronto.ca
Abstract. The fate and transport of methylmercury (MeHg) were studied in a small boreal catchment. Hydrological processes largely govern the magnitude of the flux of MeHg. Seasonal and inter-annual variability in hydrology produce variable source strengths of MeHg throughout the catchment. The mass flux of MeHg within, and from the catchment is dependent on the mass flux of water and the relative placement of landscape units in the catchment hydrological cascade. Hydrology also governs the maintenance of the methylating environments in the catchment. Specifically, hydrological processes maintain zones of anoxia in both the catchment uplands and peatlands that support obligate anaerobic sulphate-reducing bacteria. In addition, groundwater flow paths are an essential control on the delivery of sulphate to these bacteria that facilitate in situ mercury methylation.

Keywords: methylmercury, methylation, hydrology, boreal catchment, peatland, Ontario, Canada



Citation: Branfireun, B. A. and Roulet, N. T.: Controls on the fate and transport of methylmercury in a boreal headwater catchment, northwestern Ontario, Canada, Hydrol. Earth Syst. Sci., 6, 785-794, doi:10.5194/hess-6-785-2002, 2002.
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