Flood hydrology and methylmercury availability in Coastal Plain rivers

Environmental Science & Technology
By: , and 



Mercury (Hg) burdens in top-predator fish differ substantially between adjacent South Carolina Coastal Plain river basins with similar wetlands coverage. In the Congaree River, floodwaters frequently originate in the Blue Ridge and Piedmont regions, where wetlands coverage and surface water dissolved methylmercury (MeHg) concentrations are low. Piedmont-driven flood events can lead to downward hydraulic gradients in the Coastal Plain riparian wetland margins, inhibiting MeHg transport from wetland sediments, and decreasing MeHg availability in the Congaree River habitat. In the adjacent Edisto River basin, floodwaters originate only within Coastal Plain sediments, maintaining upward hydraulic gradients even during flood events, promoting MeHg transport to the water column, and enhancing MeHg availability in the Edisto River habitat. These results indicate that flood hydrodynamics contribute to the variability in Hg vulnerability between Coastal Plain rivers and that comprehensive regional assessment of the relationship between flood hydrodynamics and Hg risk in Coastal Plain streams is warranted.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Flood hydrology and methylmercury availability in Coastal Plain rivers
Series title Environmental Science & Technology
DOI 10.1021/es102917j
Volume 44
Issue 24
Year Published 2010
Language English
Publisher ACS Publications
Publisher location Washington, D.C.
Contributing office(s) Toxic Substances Hydrology Program, South Atlantic Water Science Center
Description 6 p.
First page 9285
Last page 9290
Country United States
State South Carolina
Other Geospatial Coastal Plain, Congaree River basin, Edisto River basin
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