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<br />razorback suckers. Seventy-six pools larger than 80 square feet were documented in Anderson's <br />fall survey. Twenty-five potential Colorado squawfish spawning sites, comprised of sediment-free. <br />cobble bars adjacent to pools greater than 160 square feet, were reported by Anderson. The <br />combination of cobble bars adjacent to pools are required as spawning sites for Colorado <br />squawfish (Tyus, 1986, 1990, 1991). Although water temperatures in the Colorado River reach <br />above the diversion dams is cooler than downstream, Colorado squawfish will spawn at these <br />temperatures. Recently hatched fish drift and grow in downstream reaches from spawning sites <br />where temperatures are more suitable for their growth. Therefore; the overall area upstream from <br />the diversion dams contains suitable habitat for both endangered fish species. The 54-mile reach <br />of the Colorado River upstream from Palisade contains lower selenium levels than downstream <br />reaches. There is some concern that high selenium concentrations may adversely impact the <br />reproductive success of adult endangered fishes and could be toxic to young fish resulting in high <br />mortality to the point that no young fish survive. <br /> <br />Related Proiects <br /> <br />Many existing water projects and related activities are in place on the Colorado River, and new <br />developments are being considered. Transmountain diversions, irrigation projects, direct <br />irrigation diversions, and a growing human population occur upstream, <br /> <br />In addition to provision of fish passage, the Recovery Program contains other related activities. <br /> <br />One .of the Recovery Program endeavors includes captive propagation of endangered fish to be <br />used for stocking river reaches of historic habitat that have been designated as critical for <br />recovery of the endangered fishes. The razorback sucker, which has exhibited a dramatic decline <br />in the Upper Colorado River between the 1970's and 1980's (Burdick 1992), could benefit from <br />stocking. Burdickreported that a record catch of206 razorback suckers during various studies <br />(primarily in the Grand Valley) occurred in 1975, but no fish were captured between 1989 and <br />1992. Since 1992, only a few individual razorback suckers have been collected from the Upper <br />Colorado River by investigators who are conducting studies under the Recovery Program. <br /> <br />Brood stocks for use in captive propagation are being developed following "Genetics <br />Management Guidelines" that were developed by the Recovery Program using wild adult <br />endangered fish, At the present time, a broodstock for razorback suckers is being developed for <br />stocking historic reaches in the Colorado and Gunnison Rivers that are either presently <br />unoccupied or that contain few endangered fish. Stocking plans have been developed for <br />restoration and augmentation stocking the razorbacks in both rivers. To date, experimental <br />stocking of razorback suckers has been made in the Gunnison to evaluate various factors such as <br />the size of fish that would provide the best survival after stocking. As captive-reared razorback <br />suckers are available, stocking of the Colorado River upstream from the diversion dams is <br />proposed in the stocking plans. Development of a brood stock for Colorado squawfish has been <br />initiated also, Anderson (1997) has made recoinmendations for stocking of these fish in the reach <br /> <br />3 <br />