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Late Juvenile and Adult Monitoring <br />The late juvenile and adult fish community was sampled on twelve occasions throughout the five <br />year study. The overwhelming majority of effort was expended in the upper canyon (upstream of <br />the major rapids in. Westwater Canyon), i.e. between RM 124.5 and 119.5. Humpback chubs <br />were collected on every occasion at every site sampled in the upper canyon. On two occasions <br />sampling occurred in the lower canyon (below the rapids) at RM 114.3 in April of 1992 and at <br />RM 116.5 in July of the same year. Humpback chub were not collected in the lower canyon and <br />roundtail chubs were collected in lower than upstream. [YOY CPEs were significanlty less from <br />this area of the canyon]. For this reason, subsequent to July i 992, sampling was concentrated in <br />the upper canyon. <br />Native species dominated the collections of larger sized fish, both along the shorelines <br />(electrofishing and hoop netting) and in the main channel (trammel netting). Native chubs <br />accounted for 57.4% and 71.4% of the electrofishing and hoop net catch, respectively, with the <br />overwhelming majority of those fishes collected electrofishing (Figures 12). Roundtail chubs <br />were the most abundant species collected at the Miner's Cabin site, but were outnumbered by <br />unidentified juvenile chubs at the lower two. Main channel habitats were sampled with trammel <br />nets. More effort was expended on this technique than any other and itproduced 57.3% of our <br />total catch (N=3992). Native chubs dominated the trammel net catch; humpback chubs <br />accounted for 28.6% of the total catch, roundtail chubs were the most abundant species <br />accounting for 37.3%, and unidentified chubs comprised 6.4% all sites combined (Figure 13). <br />Again roundtail chubs were the most numerous species collected throughout the study at each of <br />the three intensively sampled sites followed closely by humpback chubs. Juvenile Gila spp. and <br />other unidentified adult chubs were more abundant at the two lower sites but did not comprise <br />more than 10 % of the total trammel net catch at any location. <br />DRAFT <br />' 30 <br />