Title: | "Are methylmercury concentrations in the wetlands of Kejimkujik National Park, Nova Scotia, Canada, dependent on geology?" |
Author(s): | Siciliano SD; Sangster A; Daughney CJ; Loseto L; Germida JJ; Rencz AN; O'Driscoll NJ; Lean DR; |
Address: | "Dep. of Soil Science, Univ. of Saskatchewan, 51 Campus Drive, Saskatoon, SK, Canada S7N 5A8. Siciliano@sask.usask.ca" |
ISSN/ISBN: | 0047-2425 (Print) 0047-2425 (Linking) |
Abstract: | "In the relatively pristine ecosystem in Kejimkujik Park, Nova Scotia, methylmercury (MeHg) concentrations in loons, Gavia immer, are among the highest recorded anywhere in the world. This study investigated the influence of bedrock lithology on MeHg concentrations in wetlands. Twenty-five different wetland field sites were sampled over four different bedrock lithologies; Kejimkujik monzogranite, black sulfidic slate, gray slate, and greywacke. Soil samples were analyzed for ethylmercury (EtHg), MeHg, total Hg, acid-volatile sulfides (AVS), organic matter, and water content as well as the biological parameters, mercury methyltransferase (HgMT) activity, sulfate reduction rates, fatty acid methyl ester (FAME) composition, and acidity. Methylmercury concentrations in the wetlands were highly dependent (P < 0.08) on lithology with no significant difference between bogs, fens, and swamps. Methylmercury concentrations in wetland soils developed on Kejimkujik monzogranite averaged 900 ng kg(-1) compared with only 300 ng kg(-1) in wetland soils developed on black sulfidic slate. Fatty acid methyl ester composition was also lithologically dependent (P < 0.001) with biomarkers for Desulfobulbus spp. discriminating between sites containing high and low MeHg concentrations. Levels of MeHg in wetlands were predicted mainly (41% of the sum of squares) by HgMT activity that differed (P < 0.009) between wetlands, with activity in bogs almost three times that present in swamps. Wetland MeHg concentrations are highly dependent on the lithology on which they have developed for largely biological reasons" |
Keywords: | "Animals Birds/*metabolism Environmental Monitoring/methods Geologic Sediments/analysis Humans Methylmercury Compounds/*analysis Nova Scotia Soil Pollutants/*analysis Water Pollutants, Chemical/*analysis;" |
Notes: | "MedlineSiciliano, Steven D Sangster, Al Daughney, Chris J Loseto, Lisa Germida, James J Rencz, Andrew N O'Driscoll, Nelson J Lean, David R S eng Research Support, Non-U.S. Gov't 2003/12/17 J Environ Qual. 2003 Nov-Dec; 32(6):2085-94. doi: 10.2134/jeq2003.2085" |