Lower Colorado Basin GIS Fish Data

Peter J. Unmack
Biology Department
Arizona State University
Tempe AZ 85287-1501, USA.

Two sets of information are available here, the dataset and the manual. In order to understand the dataset, you must read the manual as it contains all the documentation of where the data came from, what the field definitions are, and how to view and manipulate the dataset (if you are unfamiliar with ArcView). If you have any questions relating to this website or the dataset please contact Peter Unmack at .

GIS Dataset

The dataset, called coloradofishes.shp can be downloaded from here as a zip file or as a self extracting zip file. The current version is dated June 4, 2002. You must also read the documentation available from below. You will need winzip to open the file, but you probably already have that on your machine. If not go to www.winzip.com and download their free version. You will need ArcView to view the data. There is a free version called arcexplorer that you can use to view the data in. It can be downloaded from http://www.esri.com/software/arcexplorer. I don't think it really matters which version you download. However, I'd suggest version 2. I do not presently have instructions for using arcexplorer, hence it could be a little tricky to figure out.

Documentation and Manual

The dataset will allow you to view native and exotic fish records based on presence/absence from a particular watershed within the Lower Colorado Basin below Lake Powell, except for Salton Sea. Some additional data are also included, such as the number of native species by watershed by two time periods, percentage and absolute decline in natives, and extant exotic fish records. The dataset can also be manipulated to display various combinations of the data. Instructions on how to do that can be found below.

The documentation and manual is only available as a single pdf file at this stage. It can be viewed or downloaded here.

A copy of the legend file is contained within the coloradofishes.zip file. However, you can also download a copy of the legend file if you right click here and select " save link as" (in Netscape), or save target as (in Explorer), which will allow you to save the file to your hard disk.