Accession Number : ADA323066

Title :   Instream Flows to Assist the Recovery of Endangered Fishes of the Upper Colorado River Basin.

Descriptive Note : Technical rept.,

Corporate Author : FISH AND WILDLIFE SERVICE DENVER CO

Personal Author(s) : Stanford, Jack A. ; Nelson, Patrick C.

PDF Url : ADA323066

Report Date : JUL 1994

Pagination or Media Count : 53

Abstract : The riverine landscape of the Upper Colorado River Basin has been extensively modified by dams, diversions, revetments, and water abstractions. These changes, probably coupled with the introduction of many nonnative fishes, have compromised the existence of four of the native fishes (Colorado River squawfish Ptychocheilus lucius, humpback chub Gila cypha, bonytail chub Gila elegans, and razorback sucker Xyrauchen texanus) of the river system. Efforts to recover these endangered fishes have emphasized reregulation of flows to provide better habitat conditions than existed during the last half century; when ranges and abundances of the fishes declined significantly. Contention emerged, however; with regard to the efficacy of methods used by the U.S. Fish and Wildlife Service to justify flow recommendations to protect the endangered fishes. The purpose of this study was to review the science pertaining to the issue of flow provision, to identify critical uncertainties, and to provide recommendations for determining the instream flow needs of the endangered fishes.

Descriptors :   *ENDANGERED SPECIES, *FISHES, *STREAMFLOW ANALYSIS, *COLORADO RIVER, WATER, HABITATS, WILDLIFE, BASINS(GEOGRAPHIC), EMBANKMENTS, DAMS, REVETMENTS.

Subject Categories : Biology
      Hydrology, Limnology and Potamology

Distribution Statement : APPROVED FOR PUBLIC RELEASE