In order to determine the current status of and detect any long-term trends in the environmental quality of U.S. nearshore waters, NOAA initiated the National Status and Trends program in 1984 with its National Benthic Surveillance Project. The primary objective of the Benthic Surveillance Project was to quantify concentrations of a suite of organic and inorganic contaminants in the livers of fish and surficial sediments from selected sites in the coastal and estuarine waters of the United States. In addition, the levels of certain indicators of the biological effects of these contaminants were measured. Incidences of visible lesions, including fin erosion, have been noted and histopathological examinations of various tissues have been carried out. Originally histopathological examinations determined the prevalence of any identifiable disease conditions in samples of liver, kidney, and gill tissue.In addition the Benthic Surveillance Project analyzed fish liver tissue sample for cytochrome P4501A (CYP1A) activities in liver via analysis for aryl hydrocarbon hydrolase (ahh). The induction of hepatic CYP1A activity is one of the earliest physiological changes detected after exposure to chemical contaminants. A number of studies have shown that measurement of these biochemical alterations combined with measurement of the above-mentioned injuries, give a more consistent assessment of contaminant exposure in indigenous fish that do single bioeffects measurements.