Desert Fishes Council, Page, AZ, November 1998.

The fish are going on the byte: GIS analysis of western fishes.

P.J. Unmack & W.L. Minckley

Individual fish records for the Lower Colorado Basin, Great Basin, and northwestern Mexico have been brought into a GIS database in various stages of development. Data are based upon museum records, primary literature, and some gray literature. The purpose of this work is multifaceted and includes: determining present centers of native fish diversity, changes in occurrence over time, analysis of factors causing declines, building predictive models of fish occurrence, and others. GIS is a powerful analysis tool which is useful for basic tasks such as creating distribution maps through complicated statistical spatial analysis. A brief overview of our techniques is provided including some of the limiting factors. Data for the Gila, Little Colorado, Bill Williams, and Virgin rivers are presented.