The Quality of Our Nation’s Waters: Mercury in the Nation’s Streams—Levels, Trends, and Implications

Wentz

The United States has made major investments in assessing, managing, regulating, and conserving natural resources, such as water, minerals, soil, and timber. Sustaining the quality of the Nation’s water resources and the health of our ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and long-term economic, social, and environmental benefits that make a difference to the lives of millions of people. The U.S. Geological Survey (USGS) is committed to providing the Nation with reliable scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov). Information on water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation, and that is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of water, measured in terms of quantity and quality, essential to the long-term sustainability of our communities and ecosystems. Mercury is a pervasive contaminant of streams and lakes, and has resulted in fish consumption advisories in all 50 States. The current report, “Mercury in the Nation’s Streams—Levels, Trends, and Implications,” presents a summary of results from USGS investigations conducted since the late 1990s on the sources, occurrence, trends, transport, and bioaccumulation of mercury in stream ecosystems. The report draws from studies conducted by several USGS Programs, including the National Water Quality Assessment, Toxics Substances Hydrology, and National Research Programs. This report is one of a series of publications, The Quality of Our Nation’s Waters, which describe major findings of the USGS on water-quality issues of regional and national concern. Other reports in this series focus on the occurrence and distribution of nutrients, pesticides, and volatile organic compounds in streams and groundwater; the effects of contaminants and streamflow alteration on the condition of aquatic communities in streams; and the quality of untreated water from private domestic and public supply wells. Each report builds toward a more comprehensive understanding of the quality of regional and national water resources (http://water.usgs.gov/nawqa/nawqa_sumr.html). The information in this series is intended primarily for those interested or involved in resource management and protection, conservation, regulation, and policymaking at regional and national levels. In addition, the information should be of interest to those at a local level who wish to know more about the general quality of streams and groundwater in areas near where they live and how that quality compares with other areas across the Nation. We hope this publication will provide you with insights and information to meet your needs, and will foster increased citizen awareness and involvement in the protection and restoration of our Nation’s waters.