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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />3-3 <br /> <br />3.1.2 Releases To The Wild <br /> <br />The progeny of the 1974 wild broodstock have been used primarily for <br />research on chemical tol erances, behavi oral trai ts, physi 01 ogi ca1 demands <br />(Bulkl ey et al. 1981; Bel eau and Bartosz 1981), and early 1 ife <br />stage development (Seetha1er 1978; Snyder 1981). Hatchery-reared <br />Colorado squawfish have been released in the wild at three sites (Figure 1): <br /> <br />1. Potash, Utah: about 1500 si x-year 01 d squawfi sh (age group V I, <br />1974 year class) were tagged with Carlin fingerling tags in February 1980 at <br />the Willow Beach NFH. These 8 to 15-inch fish were released in April 1980 <br />at Potash (river mile 47.3) on the Colorado River, about l7 river miles <br />downstream of Moab, Utah (Valdez et al. 1982). As of September 1983, 15 <br />of these fi sh had been recaptured. These showed good growth, an <br />adaptability to wild conditions, and substantial movement from the release <br />site (Valdez et ale 1982; Valentine 1983). <br /> <br />2. Grand Junction, Colorado: about 30,000 fingerling (2-3 inch) <br />squawfish from Dexter NFH were implanted with coded wire nose tags and <br />released into the backwaters and gravel pits along the upper Colorado River <br />near Grand Junction in October 1982. An additional 86,600 advanced fry and <br />fingerlings, also marked with nose tags, were transferred to the area in <br />October 1983. The purpose of these introductions was to assess the <br />survivability and adaptability of the young fish to natural backwaters as <br />well as artifi cially-created, ri versi de gravel pi ts (Osmondson and <br />Berry 1984). The young squawfi sh, which were stocked at 38-88 11111 TL <br />(total length) in October were 110-120 11111 TL and in good condition when <br />recaptured in July 1983 by personnel of the Utah Cooperative Fishery <br />Research Unit (Osmondson and Berry 1984) and CRFP (Valentine 1983). Most <br />of the 30,000 fish released near Grand Junction were contained in isolated <br />gravel pits, although some were placed in open backwaters with access to <br />the main Colorado River. In 1984, two additional releases of marked <br />young squawfish from Willow Beach NFH were made into gravel pits and <br />backwaters near Grand Junction; 25,802 in August 1984 and 30,649 in <br />October 1984. <br /> <br />3. Bridgeport, Colorado: about 10,700 marked fingerling squawfish from <br />the Dexter NFH were released in the lower Gunnison River near Bridgeport, <br />Colorado, about 30 miles above the confluence of the Colorado River. These <br />fish were released in November 1984 to assess the adaptability of the <br />species to the Gunnison River and to provide a stock of squawfish in the <br />lower Gunnison River for investigating movement of the species through the <br />Redlands Diversion Dam located about 3 miles above the Colorado River <br />confluence. <br /> <br />All Colorado squawfish released in the wild have been uniquely-marked. <br />The fish released at Potash (1500) were marked with sequentially-numbered <br />Carlin fingerling tags and those of the other groups (30,000; 86,600; <br />25,802; 30,649; 10,700) were marked with uniquely-coded internal wire <br />nose tags. These marking techniques enable distinctions to be made <br />between wild and hatchery-reared fish captured afield. Thus, a total of <br />185,251 marked Colorado squawfish have been released in the lower <br />Gunnison River and the upper Colorado River near Grand Junction, Colorado <br />and Potash, Utah. <br />