Article

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

U.S. Geological Survey, 2280 Woodale Drive, Mounds View, Minnesota 55112, USA.
Environmental Science and Technology (Impact Factor: 5.48). 05/2009; 43(8):2720-5. DOI: 10.1021/es802694n
Source: PubMed

ABSTRACT This paper is freely available via Open Access: http://pubs.acs.org/doi/abs/10.1021/es802694n

We studied total mercury (THg) and methylmercury (MeHg) in eight streams, located in Oregon, Wisconsin, and Florida, that span large ranges in climate, landscape characteristics, atmospheric Hg deposition, and water chemistry. While atmospheric deposition was the source of Hg at each site, basin characteristics appeared to mediate this source by providing controls on methylation and fluvial THg and MeHg transport. Instantaneous concentrations of filtered total mercury (FTHg) and filtered methylmercury (FMeHg) exhibited strong positive correlations with both dissolved organic carbon (DOC) concentrations and streamflow for most streams, whereas mean FTHg and FMeHg concentrations were correlated with wetland density of the basins. For all streams combined, whole water concentrations (sum of filtered and particulate forms) of THg and MeHg correlated strongly with DOC and suspended sediment concentrations in the water column.

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