SS3.17 Global Mercury Cycling: From Natural to Anthropogenic Sources
Date: Tuesday, June 11, 2002
Time: 9:45:00 AM
Location: Carson C
ClairTA, Environment Canada, Sackville, NB, Canada,
Arp, P, A, Faculty of Forestry, University of New Brunswick, Fredericton, NB, Canada,
Meng, F, R, Faculty of Forestry, University of New Brunswick, Fredericton, NB, Canada,
Lean, D, R, Dept. of Biology, University of Ottawa, Ottawa, ON, CANADA,
Geographical, hydrological and biophysical factors controlling surface water total and methyl mercury concentrations in the surface waters of Kejimkujik Nationa
Loons studied in Kejimkujik NP have some of the highest concentrations of Hg in their feathers of any of the birds measured in North America. Preliminary evaluation of Hg in biota and water area revealed that total mercury (Hgt) levels were positively correlated with the aquatic dissolved organic carbon, which itself is a function of the presence of littoral wetlands in basins. The objective of the study was to see how Hgt and methyl mercury (MeHg) concentrations relate to each other and with dissolved organic carbon (DOC) in the Park region during biologically active and dormant periods. We show that during both the summer and early spring, there is a strong correlation between Hgt and MeHg with DOC. There is also a strong, significant relationship between Hgt and MeHg in the summer time at 25 sites sampled, where MeHg is approximately 10% of Hgt. This relationship does not hold in the early spring, as MeHg is at a low consistent value throughout the ecosystem. This is most likely due to the lack of biological methylation occurring in winter. We then constructed a geographic information system model to predict concentrations of Hgt and MeHg in the Kejimkujik systems using basin slope, wetness, and solar influence as independent variables.