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3, Complete construction of primary refuges for the Green River Subbasin and the Upper Colorado River Subbasin in FY 1996. 4. Construct or lease waters to be used as backup refuges for priority broodstocks or captive-reared research fish to meet Recovery Program needs. 5. ModifY riverside ponds as growout ponds to rear endangered fish for stabilization or reintroduction stocking. Past efforts have demonstrated that riverside ponds are highly productive for rearing endangered fish but that there are problems with capturing fish when they are needed by the Recovery Program. Many riverside ponds are not drainable but water can be pumped out of them. Sloping the bottom of the ponds and installing a catch basin (i.e., kettle or trap) will solve the problem of capturing fish when the ponds are drained. 6. Use hatchery facilities for the initial rearing of the endangered fishes and transfer the fish to growout ponds along the rivers when feasible. Harvest fish from the growout ponds to conduct field experiments on survival of captive-reared fish after stocking into Upper Basin rivers. V. RESEARCH, MONITORING, & DATA MANAGEMENT 14 POPULATION SIZE/AGE STRUCTURE This study is evaluating the size, age structure, distribution of the adult squawfish population in the upper Colorado River for comparison with similar data collected IS years ago. This will allow us to draw conclusions about population status and form a baseline by which we can gauge progress of recovery efforts. A secondary goal of the survey is to determine survival and distribution of hatchery-reared squawfish stocked in the Colorado and Gunnison rivers during 1982-1984. This information will be particularly useful in evaluating the usefulness of stocking in recovery. Both study goals are being met. Large samples of adult Colorado squawfish were obtained allowing for reliable size-frequency analysis as well as estimates of the peFCentage of the population comprised of stocked individuals. Recapture rates were high (50%), allowing for a fairly good confidence interval around a population point estimate of the adult population above Westwater Canyon. Tbe data collection portion of this study was completed in 1994. A draft report was due in January 1995 and a final report in May 1995. Both due dates were not met because of a higher priority placed on a concurrent report needed fOf an instream flow filing on the Colorado River. Recommendations: We recommend that studies such as this one be fepeated periodically in the Colorado River so tbat trends in population status can be more accurately monitored. The overall population is small, making it more vulnerable to extirpation than in the Green River Basin where squawfish are more numerous. To calculate a population estimate, a minimum of three years of data collection is required; to calculate a survival rate at least four years are required, The next four-year study should probably commence after five years have lapsed since the end of this study. A A-27