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higher for the 1993 cohort than the other two (Table 10). Nigh spring floods subsequent to a <br />cohort's first overwinter period did not prove detrimental and may have been beneficial to their <br />survival. <br />Relative survival of Age 1 to Age 2 is presented for each of the cohorts (Figure 9). <br />Electrofishing catch rates declined very little for this Iife history stage suggesting high survival <br />rates once chubs reach 100mm TL. The 1992 and 1994 cohorts experienced moderate to high <br />winter flows during their second winter period; second winter flows were low for the 1993 cohort <br />The second spring peak was extremely low for the 1992 cohort, moderate for the 1994 cohort <br />and high for the 1993 cohort. <br />Fall length frequencies of the chubs by species indicate the structure of the adult ('identifiable) <br />portion of the humpback and roundtail chub populations remained relatively stable throughout the <br />study (Figures 10 aad 11). The roundtails were more numerous throughout these fall samples. <br />A Kohnogorv-Smirnov analysis of these frequency distnbutions (all years combined) indicated the <br />adult roundtail are significantly smaller animals than the adult humpback adult population (KS <br />stet = 0.23; p=.00). The average length of roundtails collected in Westwater was least in 1992 <br />(236.8mm) apparently the year of strongest roundtail chub recruitment to the adult population in <br />this five year study.- -Mean length of roundtails remained remarkably consistent for the remainder.. <br />of the study hovering near 260mm TL. Average size of adult humpback chub ;fluctuated more <br />throughout the study ranging between a low of 253.2mm in 1992 to a high of 287.3. in 1995. The <br />annual length fi-equencies analysis for humpback chub indicate individuals recruited to the adult~~ <br />population ('individuals > 200mm TL) consistently and perhaps best in 1996. <br />DRAFT <br />27~~ ~~ <br />