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<br />002825 <br /> <br />Introduction <br />The propagation and stocking of the Colorado River endangered fishes is recognized as <br />one of five primary approaches to attaining the recovery goals for the four listed species- <br />razorback sucker, Colorado squawfish, bony tail, and humpback chub, The direction to perform <br />tasks related to propagation, augmentation, and restoration stocking are clearly identified in the <br />Recovery Implementation Program report (U,S, Fish and Wildlife Service 1987), the recovery <br />action plan (U.S. Fish and Wildlife Service 1994), and the annual propagation operation plan <br />(Czapla 1997). <br /> <br />Three razorback sucker stocks, three Colorado squawfish stocks, five humpback chub <br />stocks, and one bonytail stock have been identified (Wydoski 1995). Populations of these <br />species in Colorado rivers that contribute to, or are included within the critical habitat range of <br />these presumptive stocks include both razorback sucker and Colorado squawfish populations in <br />both the Colorado River from Rifle downstream to the state line, and in the Gunnison River <br />from Delta downstream to its confluence. These populations are part of the Upper Colorado <br />River stock for each species, Colorado squawfish populations in the Yampa and White rivers <br />contribute to the Yampa and Green River-Desolation/Gray Canyon stocks. Presumptive stocks <br />of humpback chub in Colorado include the populations in the Yampa River and Colorado River <br />at Black Rocks Canyon, Bonytail populations formerly occurred in Colorado, based on captures <br />and identifications of this species in the Yampa, Colorado, and Dolores rivers in historic and <br />anecdotal accounts (Tyus and Karp 1989, Kaeding et al, 1986, Quartarone 1993), but are now <br />extirpated, This species is now represented by only one captive stock at Dexter National Fish <br />halchery in New Mexico, Relict wild stocks exist in Lake Havasu and Lake Mohave in the <br />Lower Colorado River Basin, but are comprised of very old, senescent adults (USFWS 1990a), <br /> <br />This stocking plan provides the rationale for conducting restoration stocking of three of <br /> <br />the four endangered fish species in select rivers of western Colorado within the Upper Colorado <br /> <br />River Basin, and includes priorities among species and river reaches, genetics risk assessment, <br /> <br />and criteria for contribution to recovery success as well as expectations and limitations. <br /> <br />DRAFT - June 4, 1997 <br /> <br />1 <br />