You are here: Home › Stressors › Pollution › Research Assessments › Sediment Coring Studies
Sediment Coring Studies
These studies address historical contaminants trends in estuarine and coastal sediments. Changes in the environment due to the Industrial Revolution, dating from the middle of the 19th century, are very well known.
These changes are expressed by increased levels of natural components, such as trace metals and nutrients, but also by the increase of anthropogenic compounds, such as polychlorinated biphenyls (PCBs) and pesticides.
Since the early 1960s, regulatory measures have been taken to decrease the amount of pollutants entering our waterways, but the bulk of these environmental measures were not enacted until the 1970s.
Because of the scarcity of accurate data, due to lack of sensitive techniques or of regular data collection in the past, the extent of the past pollution and the effect of the recent legislative limitations is often difficult to access.
One way to address this problem is through the analysis of sediment cores. Most pollutants have an affinity for and adsorb easily onto sediments and fine particles. Therefore, by analyzing cores of undistributed sediments, it is possible to assess the historic pollution of a given system.
Sediment cores reflect not only the history of pollutant concentrations but also register the changes in the ecology of a water body. For example, changes in estuarine eutrophication are reflected in the concentration of organic matter, nitrogen, and phosphorus, while lake acidification is translated into changes in diatom assemblages.
The use of cored sediments to reconstruct the chronology of coastal and estuarine contamination is not, however, devoid of problems and caution must be exercised. Sediment mixing by physical or biological processes can obscure the results obtained by such studies, and sophisticated methods must be used in cases to tease out the desired information.
Project Partners
Johns Hopkins University
Maryland Geological Survey
College of William and Mary
Skidaway Institute of Oceanography,
University of Georgia
University of Delaware
University of California, Los Angeles
Oregon State University
Related Reports
Historical Reconstruction of Contamination Using Sediment Cores: A Review
EAST COAST
Hudson/Raritan Estuary
Long Island Sound marshes
Chesapeake Bay
Savannah Estuary
GULF COAST
Tampa Bay
Mississippi River Delta
Galveston Bay
WEST COAST
Southern California Bight
San Francisco Bay
Puget Sound