Fish habitat of the Edisto River Basin in South Carolina was evaluated using a geographic information system (GIS). A committee of fisheries biologists was formed to evaluate fish habitat within the Basin, and the GIS was used to compile and analyze data and generate maps to represent quality of fish habitat. United States Geological Survey (USGS) 1:24,000-scale digital line graph (DLG) hydrography data were assigned values for data on species composition, predesignated protected areas, riparian habitat, dams and impoundments, ditches and channelization, and water quality. Criteria were developed to evaluate fish habitat in the Basin. Each criteria was assigned a point value, and these values were totaled and subdivided into Value Classes 1, 2, and 3 representing high, moderate, and low quality fish habitat, respectively. Value Class 1 consisted of 92% of the main river reaches and the entire estuarine portion of the Basin. Value Class 2 included many tributaries of the northern upstream half of the Basin. The middle portion of the Basin contained most of the Value Class 3 reaches. Greater than 75% of the 11,000 km of Basin streams contained good fish habitat. Fish habitat was analyzed using a GIS over a larger area and with more comprehensive data sets than fisheries biologists traditionally use. Fisheries biologists could benefit from using GIS products in the prioritization of sampling efforts and in locating mitigation and restoration sites
