Mercury in Aquatic Ecosystems
Mercury occurs naturally in the environment and cycles among the atmosphere, water, and sediments. Human activities such as coal burning power plants and waste incineration increase the amount of mercury cycling in the environment. Since the industrial revolution, anthropogenic mercury emissions have increased atmospheric mercury levels about threefold, causing corresponding increases in mercury levels in terrestrial and aquatic ecosystems.
Mercury that is released into the atmosphere can be transported long distances and deposited in aquatic ecosystems, where it is methylated to methylmercury. Mercury is a neurotoxicant, to which the human fetus is very sensitive. Methylmercury is an organic form of mercury, the most toxic form, and the form that bioaccumulates in fish. Wildlife and humans are exposed primarily through consumption of contaminated fish. The factors that make some aquatic ecosystems susceptible to this bioaccumulation, however, are unknown, making protection of human health and the health of fish-eating wildlife a challenge.
Research focuses on the processes of mercury methylation and accumulation in aquatic ecosystems, factors that determine ecosystem susceptibility, and investigation of whether reduced emissions will reduce mercury accumulation in susceptible ecosystems.
- National and Regional Assessments of Mercury Occurrence and Cycling in the Environment
- Mercury Experiment to Assess Atmospheric Loading in Canada and the United States (METAALICUS)
- Mercury Cycling in Aquatic Ecosystems
Aquatic ecosystems across the Nation are being studied to identify the factors
that control where and when mercury accumulates to toxic levels in the food chain
|
Program Headlines Related to Mercury Research
Fact Sheets
More information on Mercury Research
New Publications
Upcoming Publications
- Influence of plankton mercury dynamics and trophic pathways on mercury concentrations of top predator fish of a mining-impacted reservoir: Stewart, A.R., Saiki, M.K., Kuwabara, J.S., Alpers, C.N., Marvin DiPasquale, M., and Krabbenhoft, D.P., Canadian Journal of Fisheries and Aquatic Sciences, v. 65 (IN PRESS).
- A comparison of methyl mercury production and distribution in sediments of the Congaree and Edisto River Basins, South Carolina: Chapelle, F.H., Journey, C.A., and Bradley, P.M., U.S. Geological Survey Scientific Investigations Report (IN PRESS).
Newly Published
- Mercury, trace elements and organic constituents in atmospheric fine particulate matter, Shenandoah National Park, Virginia, USA--A combined approach to sampling and analysis: Kolker, A., Engle, M.A., Orem, W.H., Bunnell, J.E., Lerch, H.E., Krabbenhoft, D.P., Olson, M.L., and McCord, J.D., 2008, Geostandards and Geoanalytical Research, v. 32, no. 3, p. 279-293, doi:10.1111/j.1751-908X.2008.00913.x.
- Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach: Shanley, J.B., Mast, A.M., Campbell, D.H., Aiken, G.R., Krabbenhoft, D.P., Hunt, R.J., Walker, J.F., Schuster, P.F., Chalmers, A., Aulenbach, B.T., Peters, N.E., Marvin-DiPasquale, M., Clow, D.W., and Shafer, M.M., 2008, Environmental Pollution, v. 154, no. 1, p. 143-154, doi:10.1016/j.envpol.2007.12.031.
- Influence of natural dissolved organic carbon on the bioavailability of mercury to a freshwater alga: Gorski, P.R., Armstrong, D.E., Hurley, J.P., and Krabbenhoft, D.P., 2008, Environmental Pollution, v. 154, no. 1, p. 116-123 doi:10.1016/j.envpol.2007.12.004.
- Mercury and organic carbon dynamics during runoff episodes from a northeastern USA watershed: Schuster, P., Shanley, J., Marvin-Dipasquale, M., Reddy, M., Aiken, G., Roth, D., Taylor, H., Krabbenhoft, D., and DeWild, J., 2008, Water, Air, and Soil Pollution, v. 187, no. 1, p. 89-108, doi:10.1007/s11270-007-9500-3.
- Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region: Hall, B.D., Aiken, G.R., Krabbenhoft, D.P., Marvin-DiPasquale, M., and Swarzenski, C.M., 2008, Environmental Pollution, v. 154, no. 1, p. 124-134, doi:10.1016/j.envpol.2007.12.017.
|
|