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synthetic chemicals to provide the necessary olfaction cue to the fish when they mature. The same synthetic chemical will be dripped into the Middle Green River during the spawning seasons following the time that the fish mature to attract them to a suitable spawning site (Scholz et al. 1993). Physical ConditioninQ and Exposure to Natural Food Organisms. Pond-reared fish that are stocked into the river may not be able to cope with the riverine environment unless they are physically conditioned before release {Sanger 1993} that may result in reduced survival. Another possibility is that the fish fed pelleted food may not adapt to feeding on natural food organisms and that the fish basically "starve to death II after release. Both the bony tail and razorback sucker releases of radio-tagged fish exhibited delayed mortality so something other than, or in addition to, physical conditioning (e.g., behavioral alteration) may be involved (Cranney and Chart 1993; Burdick 1995). It is possible that the large radio-tag that is implanted in the abdomen of these fish resulted in delayed mortality of the fish. If that is the case, the use of PIT-tags would be much less stressful to the fish and should result in increased survival. Fish released in September or October during low streamflows should be able to become physically conditioned for life in the riverine environment prior to high flows during the following spring. MonitorinQ of stocked Fish. A basin-wide monitoring program is being developed through the RIP flooded bottomland enhancement and restoration program by Dr. Robert Muth, Larval Fish Laboratory, Colorado State University. An experimental field study will be conducted in 1996 that will be used to develop a monitoring program that will be suitable for the razorback sucker. Sampling of the stocked fish will be made following the guidelines and protocol that is adopted by the Recovery Program participants from the 1996 experimental field study. The sampling for fish stocked in the Middle Green River would be from the stocking location at the Split Mountain boat ramp downstream through the Ouray National Wildlife Refuge to Sand Wash. DisDosition of SurvivinQ Razorback Suckers. The intent is to stock all surviving razorback suckers into the Green River if the fish meet the "Genetics Management Guidelines" (Williamson and Wydoski 1994). If the fish do not meet the "Genetics Management Guidelines", disposition will follow the "Guidelines for Disposition of Captive-Reared Endangered Fish" (Appendix A in Stempel and Wydoski 1995). VI. REFERENCES Allendorf, F.W. 1993. Delay of adaptation to captive breeding by equalizing family size. Conservation Biology 7: 416-419. Bestgen, K.R. 1990. Status review of the razorback sucker, Xvrauchen texanus. Colorado State University, Fort Collins. Larval Fish Laboratory Contribution 44. 92 pp. Burdick, B.D. 1992. A plan to evaluate stocking to augment or restore razorback sucker in the Upper Colorado River. U.S. Fish and Wildlife Service, Colorado River Fishery Project, Grand Junction, Colorado. 56 pp. 7