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Age 1 and Age 2 Gila spp Catch rates. - an indez of recruitment <br />Relative abundance o£juvenile chubs was tracked annually within Westwater Canyon beginning in <br />1993. Juvenile chubs were collected most effectively by electrofishing shoreline areas after dark <br />The greatest catch rates occurred between RM 121-and 120.0. Juvenile chub habitat is <br />characterized by moderate depth (.3 - 1.Om) and areas of complex flow, eg. swift runs, chutes, <br />shoreline pour overs, and the associated pool habitats immediately upstream and downstream. <br />Habitats with boulder and cobble substrates or debris piles were preferred as were shallow <br />shoreline benches. Juvenile chubs were often collected in the presence of adult roundtails as <br />well as bluehead sucker, common carp, channel catfish, adult humpback chub and flannehnouth <br />sucker in order of decreasing abundance. <br />Age 1 and Age 2 Gila spp. cohorts (Table 9) could be distinguished in a length frequency <br />analysis (Appendix Table 4). By September, of most years, the Age 2+ fish had grown large <br />enough that it became difficult to distinguish from the much larger group of adult fish (many year <br />classes) whictl were 200 mm TL and larger. Chubs less than 175mm TL were not PIT tagged in <br />this study and therefore an analysis of recruitment is relegated to a comparison of catch rates . <br />Table. 9 Three cohorts of Gila spp. that were tracked through their third Browning season. <br />Length refer to the modal peaks as identified in length frequency analyses; (Appendix Table 4). <br />All fish were collected in Westwater Canyon (Colorado River miles 124.5.- 119); 1992-1996. . <br />Dates refer to fish community monitoring trips. <br /> Sep, 93 Oct, 93 Jol~p.94 Sep, 94 Sep. 95 Oet, 95 Jolt', % Sep. % <br />2992 1+ 110mm 1+ 110mm 2+ 135mm <br />1993 1+ 80ann 1+ 120mm 2+ 160mm <br />1994 1+ 110 1+ 120mtn 2+ 140mm 2+ 170mm <br />DRAFT <br />24 <br />