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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Additional publication details

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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