National Water-Quality Assessment (NAWQA) Program
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Mercury in Stream Ecosystems
The NAWQA Program is studying mercury cycling in watersheds across the Nation to build an understanding of how natural features and human activities affect the transformation, transport, and bioaccumulation of mercury in stream ecosystems. As of August 2008, mercury was the second leading cause of stream impairment throughout the Nation USEPA 303(d) list). Methylmercury is a neurotoxin that is biomagnified in aquatic food webs so that piscivorous fish and wildlife, and humans that consume fish, are potentially at greater risk of exposure to methylmercury. USGS data and research may aid in the development of more rigorous models that relate water quality to mercury bioaccumulation, thereby enhancing capabilities for predicting mercury contamination in fish.
Featured Research
Our 2nd group of studies focused on small streams in the upper Hudson River Basin in the Adirondacks of New York State, and in the upper Edisto River Basin in the Coastal Plain of South Carolina. Our publications, including those resulting from collaboration with other scientists, are available for download from our Publications page. New: Detailed descriptions of study streams
Landscape controls
on mercury in the upper Hudson River basin
Hydrology and Methylmercury Availability in Coastal Plain Streams
Mercury
in a Coastal Plain watershed: Insights from dynamic modeling and data
Spatial patterns of methylmercury in two contrasting stream basins: macroinvertebrates and fishes | stream water
Flood hydrology and methylmercury in Coastal Plain Rivers
Mercury trends in fish from rivers and lakes in the United States, 1969–2005. Major Findings | Data | Technical Announcement
Mercury in fish, water, and sediment in U.S. streams. Press Release | Podcast | Major findings
How Mercury Flows Downstream features three papers on mercury cycling in stream ecosystems from our first group of studies, in Oregon, Wisconsin, and Florida.
Key Research Questions
- What controls concentrations of mercury in stream water, sediment, and fish?
- How do biological, chemical, and other environmental characteristics govern the methylation, transport, and bioaccumulation of mercury in streams?
Links
- Toxic Substances Hydrology Program
- Mercury in the Environment
Twitter feed. DOI and USGS link policies apply.
