Please Note: The national collection of data on mercury in fish tissue available for analysis on this site was updated on September 28, 2006.The National Descriptive Model of Mercury in Fish (NDMMF) has been re-calibrated using the updated data. The updated data may be viewed in this site's Data Mapper and Fish Model Application.

Overview - What We Do

EMMMA supports mercury research and decision-making by providing tools for Mapping, Modeling, and Analysis of mercury data.

Understanding the causes and consequences of Hg contamination in the environment is a problem of enormous geographic scope and scientific complexity. Effectively addressing this task requires the integration of data and expertise from many scientific disciplines. The Environmental Mercury Mapping, Modeling, and Analysis (EMMMA) website, a joint effort of USGS and NIEHS, is designed to support environmental and health researchers, as well as land and resource managers by providing the following tools:

Online mapping tools, USGS maps, images and other thematic data from The National Map to display and analyze mercury data and to print maps. The National Map provides nationwide geographic reference composed of aerial photographs, Landsat satellite images, and geospatial data for landcover, elevation, hydrology, transportation, and geographic names.	An online model for mercury in fish-tissue, which standardizes the concentrations of mercury in fish to enable comparisons among different species, individuals of different lengths and samples of different types. The model is applied to a comprehensive national compilation of fish-tissue data to detect spatial and temporal trends in mercury concentrations that would otherwise be obscured.	Easy access to key environmental mercury datasets, including atmospheric mercury emissions, National Atmospheric Deposition Program (NADP) monitoring sites,  and mercury concentrations in fish-tissue, soils, stream sediments, and coal. All data are downloadable in shapefile format with included .dbf files.