Welcome to the Nonindigenous Aquatic Species (NAS) information resource for the United
States Geological Survey. Located at the Center for Aquatic Resource Studies, this site
has been established as a central repository for accurate and spatially referenced
biogeographic accounts of nonindigenous aquatic species. The program provides scientific
reports, online/realtime queries, spatial data sets, regional contact lists, and general
information. The data is made available for use by biologists, interagency groups, and the
general public. The geographical coverage is the United States.