Biodiversity and Management of the Madrean Archipelago II: Connecting Mountain Islands and Desert Seas, Tucson, AZ, May 2004.

Identifying areas of conservation priority for native fishes in the Southwest using GIS.

P.J. Unmack & W.L. Minckley

The American Southwest provides a stark example of a depauperate and unique native fish fauna decimated by environmental depredation, introduced non-native species, and other factors. The fauna has declined to the point where most species are biologically imperiled. Due to the restricted availability of surface water and concern for the continued existence of the fauna, the region has been intensively sampled and substantial records exist from which to build a database. This database, termed the Minckley Sonfishes database was compiled from museum records, primary, and “gray” literature and contains over 54,000 individual fish records for Southwestern drainages. Data were geographically referenced using GIS. Several components were incorporated into determining conservation priorities: present day richness for native species, threatened and endangered species richness, percentage and absolute decline in native fishes, and non-native species richness. Our results consist of a table containing those factors outlined above summarized by watersheds and stream reaches. These can then be easily graphically displayed and manipulated. The discussion will focus on various aspects relating to choosing between alternative conservation schemes as well as identifying areas of high conservation significance. A sample dataset is available from www.peter.unmack.net/gis/fish/colorado.