Desert Fishes Council, La Paz, Mexico, November 1996.

Fish on the byte: GIS analysis of fishes in the Gila River basin.

P.J. Unmack, W.L. Minckley & J. Fry

Individual fish records for the Gila River basin have been compiled based upon museum records and primary literature. Data were then geographically referenced using GIS computer software for the purpose of determining present centers of native fish diversity and changes in occurrence over time. The assimilation of data into a GIS allows ease of data display and query capability. More importantly, GIS allows for spatial analysis of relationships between biotic and abiotic factors. These factors include fish occurrence relative to perennial water, geology, large-scale stream gradient, altitude, land use, species associations, etc. A brief overview of our techniques and results will be given including a summary of the pitfalls to avoid.