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Management Guidelines" (Williamson and Wydoski 1994). If the fish do not meet the criteria set forth in the guidelines, disposition will follow the "Guidelines for Disposition of Captive-Reared Endangered Fish" (Appendix A in Stempel and Wydoski 1995). A. Goals 1. To re-introduce razorback sucker into the Upper Colorado and Gunnison rivers and establish an adult population of 10 fish per river mile. The target is to re-establish a population of about 600 adult razorback suckers from Austin, Colorado downstream 68 river miles to the confluence with the Colorado River. In the Colorado River, the target is to re-establish a population of about 1,200 adult razorback suckers . between Rifle, Colorado and Westwater Wash, Utah (105 river miles). It is expected that razorback suckers will also become established in the Colorado River downstream from Westwater Canyon. Final goals for population parameters in the different reaches will result from Interim Management Objectives. 2. To evaluate the relation between survival of razorback sucker and size at release into the river by stocking captive-reared fish. B. Objectives 1. To determine the relationship between the size of razorback sucker stocked and their subsequent survival in the wild. 2. To determine the dispersal of stocked fish of various sizes following release. 3. To determine habitat use of juvenile (4-inch) or sub-adult (8-12-inch) fish in the riverine environment. 4. To identify ways to reduce mortality of stocked fish. 5. To evaluate different gears for sampling juvenile and sub-adult razorback sucker that will be needed to develop a monitoring program for this species. 6. To provide recommendations for the optimum size(s) for stocking razorback sucker into Upper Colorado River Basin rivers. C. Risk Assessment Burdick (1992) identified the potential risks associated with stocking captive-produced fish into wild populations and also listed strategies that could be employed to minimize direct and indirect negative genetic impacts on wild razorback sucker populations and the ecosystem. Two small risks associated with this stocking plan are: 4