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<br />1 <br /> <br />1 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />among seasons and years due to differences in flow level and availability of suitable sampling <br />areas. Similar to adult sampling, light-trap sampling effort at individual sites or reaches varied <br />areas so effort by sites was not reported. <br />In each sampling area, 1 to 10 light traps were set at dusk and were emptied prior to dawn <br />each sampling day. Light traps were described by Muth et al (1998). In the middle Green River, <br />light-traps were usually set twice per week after catostomid larvae were first detected and <br />sampling continued for until few or no additional larvae were captured, usually by mid- to late <br />June. Additional samples were collected in the middle Green River in 1999 to capture larvae for <br />brood stock development. Razorback sucker larvae were identified alive, based on their small <br />size relative to other catostomids, and transported to Ouray National Fish Hatchery. Sampling in <br />the lower Green River was less regular and dictated more by timing of associated sampling trips <br />in this more inaccessible area. Lower Green River sampling in 1993 and 1994 was viewed as <br />exploratory (Muth et al. 1998). Samples other than those for brood stock were preserved in <br />ethanol for later identification in the laboratory. <br />Data analysis, adults.-We first present data and summary statistics for adult razorback <br />suckers collected under Basinwide sampling from 1996 to 1999. We then present all available <br />adult razorback sucker capture data from the Green River Basin during those and previous years. <br />Fish were counted as captured only once per year for purposes of data analysis, even though a <br />few individuals were captured twice in the same season. Since 1991, adult fish were tagged with <br />PIT tags, data obtained prior to then were from Carlin-tagged fish. This difference was <br />potentially important because loss rates of Carlin tags may be quite high, whereas PIT-tag loss <br />was assumed to be zero. Differences in tag-loss rates may affect interpretation of apparent <br />survival-rate estimates in the two periods and may also affect number of recaptures available to <br />6 <br /> <br />