Rare and Endangered Colorado River Fishes Sensitive Areas

Upper Colorado River Biological Sub-Committee

The initial set of criteria and list of sensitive areas was provided to the Upper Colorado River Biological Sub-conmittee (UCRBS) by Fish and Wildlife biologists. It was subsequently amended by the U-, and other data were applied to make the present list more comprehensive. The current list is considered a product of the Sub-committee. Our goal was to accurately and fairly represent the state of current knowledge and understanding of habitat use by Colorado squawfish, humpback chub and razorback sucker. The focal point of our assessment was the Colorado squawfish. The bonytail was not extensively treated, for lack of data. Based upon the assessment of Fish and Wildlife Service, Colorado Division of Wildlife, and Utah Division of Wildlife Resources data, the sensitive areas represent geographic habitat usage by rare and endangered Colorado River fishes. "Confirmed-use" means that recurring and observable activities have been documented for a particular life state. On the other hand, "suspected-use" only infers that adequate replication or in-depth documentation has not occurred to date. Many "suspected-use" areas could be "confirmed" after additional research. For Endangered Species Act compliance under Section 7, suspected-and confirmed-use areas could be considered synonymous. It is hoped that the following sensitive areas will be adopted by management agencies, that the list will remain open to amendment, and that it will form the basis for various basin-wide management decisions and plans. The identification and listing of additional sensitive areas should be accomplished whenever enough data is amassed to support their inclusion. The UCRBS recomends additional research to verify suspected areas as soon as possible .