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Database of Contaminated Sediments for the Gulf of Maine

1 "Available data indicate... that the Gulf of Maine is increasingly being affected by anthropogenic stressors which have potentially synergistic and cumulative effects..."

From: The Health of the Gulf of Maine Ecosystem: Cumulative Impacts of Multiple Stressors. Convened by the Regional Association for Research on the Gulf of Maine on 18-20 September, 1995 in Hanover, New Hampshire.

Three dimensional bathymetric map of the Gulf of Maine.
Courtesy of Richard Signell, USGS-Woods Hole.

The Database as a Research Tool

Heavy metals, pesticides, petroleum compounds, and nutrients measured in Gulf of Maine sediments originate from a variety of industrial, municipal, and domestic sources. A large dataset has been compiled on contaminant deposition in coastal sediments in order to quantify the research conducted over the last 40 years. The database is to be used by the USGS and other environmental managers to assess the environmental health of regional ecosystems, the transport paths of contaminants, and the ultimate fate of those contaminants. The current database is a compilation of organic, inorganic, and texture data, sample location information, and comments on the data quality for over 7,000 sediment samples. This information may be useful to researchers for intercomparisons of more recent data as well as policy makers for remediation and resource management of urban areas in the U.S.


Sample locations in the Gulf of Maine contaminated sediment database. The database includes core and surface samples throughout the region. Areas of regional interest are outlined and include Boston Harbor, Great Bay Estuary, Casco Bay, and Penobscot Bay.

Interagency Collaboration for Data

The database of existing contaminant concentrations in sediment for the Gulf of Maine region has been compiled by the USGS Coastal and Marine Geology Program in Woods Hole in collaboration with the U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, state environmental agencies (such as the Massachusetts Water Resources Authority), and many academic and research organizations.

Database Structure

The database contains 1) original data on chemical constituents, 2) sample identification from published and gray literature sources, and 3) documentation about the quality of the data. Over 7700 sediment samples (collected primarily by core and grab samplers) are listed. The heterogeneity of the data sources resulted in differing degrees of certainty in the data; however, scientific editing identified problems and allowed many of them to be repaired or qualified for future data users.


Lead concentrations (ug/g) in Boston Harbor, MA. Red points indicate concentrations above the Toxic Effect Range-Medium (Long et al., 1995a). Orange points are between the Toxic Effect Range-Low and -Medium. Yellow indicates concentrations which are above values in soil, but below the Effects Range-Low. Blue points are low concentrations below normal soil values. Green points indicate points below natural background for lead in Massachusetts Bay.

Data Interpretation

The concentrations of metal and organic contaminants are being used to create maps of contaminant distributions in the region and investigate transport processes. This information is being transferred to scientists and environmental managers throughout the region via the World Wide Web and CD-ROM. Interpretation of the compiled data has shown that sample density is not uniform in the Gulf of Maine. Samples are concentrated in urban, coastal locations and targeted study areas, such as U.S. EPA designated National Estuaries.


(right) Lead concentrations (ug/g) in Casco Bay, Maine. Concentrations are delineated using the same system previously described. Note the prevalence of low concentrations further from the metropolitan source.

Concentrations of metal contaminants in surface sediments range from background to three orders of magnitude above natural values. The highest contaminant values in surface sediments are located near urban areas, with a halo of elevated values around them.


(left) Lead concentrations (ug/g) in Penobscot Bay, Maine. Concentrations are delineated using the same system previously described. Penobscot Bay is the interest are furthest from Boston and is dominated by low concentrations of lead. However, high values are present and indicate that the Gulf as a whole is affected by contamination.

The patchy distribution of contaminant concentrations for bulk sediments throughout the Gulf of Maine reflects both contaminant sources and sedimentary regimes. The database is a growing document that can be used by persons throughout the region for scientific and management purposes.

For More Information, please contact:
USGS Principals:
Marilyn Buchholtz ten Brink, Frank T. Manheim
USGS Assistants:
Polly Hastings, Ellen L. Mecray, Jamey M. Reid
U.S. Geological Survey, Coastal and Marine Geology Program
Woods Hole Field Center, Woods Hole, MA, 02543
Phone: 508-548-8700
Collaborating Principal Investigators:
Stephen H. Jones and Larry G. Ward, Jackson Estuarine Laboratory, University of New Hampshire
Peter F. Larsen, Bigelow Laboratory for Ocean Sciences
Bruce W. Tripp and John W. Farrington, Woods Hole Oceanographic Institution
Gordon T. Wallace, Jr., Dept. of Environmental Sciences, University of Massachusetts-Boston

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