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Mean CPUE (fish per hour of electrofishing) for the data to be compared with <br />the adult monitoring data varied greatly among the different years, reaches and <br />sampling designs (Table 2; Appendix A, Figures 1-7). When data were collected <br />in the same reach and year by more than one investigator, the catch rates showed <br />little consistency. In 19 instances where at least two investigators made <br />collections in the same reaches during the same period, only 7 exhibited <br />relatively consistent catch rates between the two investigators (as determined <br />by visual inspection of the mean t 90% confidence intervals). In the remaining <br />12 instances, 8 appeared to be greatly different. <br />One important reason for the wide variation in catch rates noted above is the <br />wide variation in sampling designs used to collect the various data sets that <br />were analyzed. None of the data sets used sampling designs that matched the ISMP <br />closely. However, data sets collected under the sampling design 'SPRING' come <br />the closest to the ISMP. Because the ISMP reaches were set up specifically for <br />the ISMP, earlier collections do not correspond well to these reaches. These <br />data sets generally represented samples from only part of the reaches designated <br />in the ISMP. In some cases, part of a reach was sampled several times while <br />other parts of the reach were not sampled at all. The other sampling designs <br />generally consisted of sampling rather restricted areas within the reaches and <br />do not appear to be as comparable with the ISMP. In addition, data collected <br />by the Colorado Division of Wildlife used a electrofishing technique designed <br />to "sneak up" on areas that might hold Colorado Squawfish. Although this can <br />be an effective method of catching Colorado squawfish, it is not one that can <br />be used to make comparisons among years unless it is done by the same <br />investigator every year. <br />7