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<br />All Colorado squawfish that were large enough to reliably identify in the <br />field wire measured in total length, counted and released alive. In the first <br />sample in a 5-mi reach all specimens were identified and counted, specimens <br />too small to reliably identify in the field were preserved and subsequently <br />identified in the laboratory. The remaining samples in the Green River were <br />field searched for Colorado squawfish only. The remaining samples in the <br />Colorado River were preserved after releasing all Colorado squawfish that <br />could be reliably identified. These samples were then searched for small <br />Colorado squawfish in the laboratory. Complete information on the sampling <br />design and the details of physical and biological data collection at each <br />sample site are presented in the ISMP Handbook. <br />Results <br />Mean catch rates (number of Colorado squawfish collected per 100 m2 <br />seined) were lowest in the upper Colorado River and highest in the lower-Green <br />River (Table 6). Catch rates for primary and secondary backwaters were <br />similar within reaches 2 and 4, but were somewhat different in reaches 1 and <br />3. Mean total length of Colorado squawfish was similar in reaches 1, 3, and 4, <br />but the one fish collected in reach 2 was quite small (Table 7). Size of <br />backwaters sampled during the monitoring program ranged between 48 and 12254 <br />m2, with maximum depths between 0.4 to 7.0 ft (Appendix A, Table 8). Red <br />shiners were the most commonly collected species in the monitoring program, <br />followed in abundance by fathead minnows and sand shiners (Appendix A, Table <br />9). <br />8 <br />