Colorado River Basin
- To determine the current distribution of the three-species in Colorado's western slope streams and rivers.
Much of western Colorado below 8,500 feet in elevation is historic native range for the three-species (flannelmouth sucker, bluehead sucker and roundtail chub). Evidence suggests the three-species only occupy about 50 percent of their historic native range in the upper Colorado River basin. Although extensive data has been collected on three-species distribution in mainstream rivers, very little exists on the presence of the three-species in smaller streams in the basin.
As a result, CPW initiated a project to rigorously determine the current distribution of the three-species within their native Colorado ranges. Researchers sampled at randomly selected locations in streams that lie within the historic native range and also at randomly selected historic sampling locations (where one or more of the three-species have been previously documented) within the Colorado River basin for three-species fish. This approach is structured to ensure that spatial balance is achieved so that the entire potential native range is included.
Researchers will continue to sample random and historic sites for three-species fish. The results from this study will give biologists a better idea of three-species distribution and abundance and help determine whether the present ranges of these fishes are stable. A better understanding of these dynamics will give fishery managers the information they need to make effective management decisions.