Spatial and seasonal variability of dissolved methylmercury in two stream basins in the Eastern United States

Environmental Science & Technology
By: , and 

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Abstract

We assessed methylmercury (MeHg) concentrations across multiple ecological scales in the Edisto (South Carolina) and Upper Hudson (New York) River basins. Out-of-channel wetland/floodplain environments were primary sources of filtered MeHg (F-MeHg) to the stream habitat in both systems. Shallow, open-water areas in both basins exhibited low F-MeHg concentrations and decreasing F-MeHg mass flux. Downstream increases in out-of-channel wetlands/floodplains and the absence of impoundments result in high MeHg throughout the Edisto. Despite substantial wetlands coverage and elevated F-MeHg concentrations at the headwater margins, numerous impoundments on primary stream channels favor spatial variability and lower F-MeHg concentrations in the Upper Hudson. The results indicated that, even in geographically, climatically, and ecologically diverse streams, production in wetland/floodplain areas, hydrologic transport to the stream aquatic environment, and conservative/nonconservative attenuation processes in open water areas are fundamental controls on dissolved MeHg concentrations and, by extension, MeHg availability for potential biotic uptake.

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Publication type Article
Publication Subtype Journal Article
Title Spatial and seasonal variability of dissolved methylmercury in two stream basins in the Eastern United States
Series title Environmental Science & Technology
DOI 10.1021/es103923j
Volume 45
Issue 6
Year Published 2011
Language English
Publisher ACS Publications
Contributing office(s) South Carolina Water Science Center, Toxic Substances Hydrology Program
Description 8 p.
First page 2048
Last page 2055
Country United States
State New York, South Carolina
Other Geospatial Edisto River, Upper Hudson River
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