The National Fish Tissue Study broadens the scope of the 1987 study (USEPA 1992) which focused on chemical residues in fish tissue near point source discharges. This new study will: provide information on the national distribution of selected persistent, bioaccumulative, and toxic (PBT) chemical residues in gamefish and bottom dwelling fish in lakes and reservoirs of the coterminous United States (excluding the Great Lakes and the Great Salt Lake); include lakes and reservoirs selected according to a probability design; involve the collection of fish from those randomly selected lakes and reservoirs over a four-year survey period (1999-2002); not be used to set fish consumption advisories; however, states and Native American tribes may choose to initiate a detailed fish study in a particular lake based on the screening contaminant concentrations provided by the National Fish Tissue Study, and include the analysis of fish tissue for PBT chemicals selected from USEPA's multimedia candidate PBT list of 451 chemicals and from a list of 130 chemicals from several contemporary fish and bioaccumulation studies. A final target analyte list of 274 PBT chemicals (including breakdown products and PCB congeners) was compiled based on input from study design workshop participants and a review team of analytical experts convened in October 1998 and March 1999, respectively.