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typical secondary channel backwaters, which may explain the general lack of use by Colorado pikeminnow. Recruitment of the YOYpikeminnow to Age 1 + Monitoring efforts for juvenile and adult fishes indicated the 1993 and 1994 cohort of YOY pikeminnow recruited to Age 1+ better than the 1992 or 1995 cohorts. Recruitment of the abundant 1996 cohort was beyond the scope of this study. Neither study measuring YOY pikeminnow abundance in Deso/Gray reported a particularly strong cohort in 1994. However, Day et al. observed excellent growth of the 1994 cohort increasing from a mean total length of 24.9 mm in July to 57.7 mm by September. Pikeminnow nursery habitat sampling near Ouray, Utah and in the lower Green River also revealed small numbers of YOY pikeminnow in 1994, however the fish in those reaches reportedly grew to an exceptionally large size by the fall as well (Trammell and Chart 1998; Day et al. 1997). This large size in the fall likely- explains the good overwinter survival. Overwinter flows are discussed above in relation to chub recruitment. In 1995, YOY Colorado pikeminnow were not encountered until September sampling and were extremely small with a mean total length of 24.8 mm (n=96). A subset of the 1996 cohort was measured at a mean total length of 38.4 mm (n=915) in September. Syrnpatric species in low velocity habitats Speckled dace was the only other native species to show a correlation between CPUE and flow parameters. Like Colorado pikeminnow, this fish showed a strong negative association (rz=0.99) to duration of flows above 75% of the peak. Fathead minnow and red shiner CPUE exhibited negative correlations with both peak flow (rZ=0.28 and rz=0.34, respectively) and duration of flow above 50% of the peak (r2=0.55 and rz=0.35, respectively). Sand shiner CPUE in August and September was negatively correlated to duration of flow the previous spring. The results of the monitoring efforts revealed little or no correlation between the densities of nonnative cyprinids and Green River peak flow. In fact, annual monitoring revealed nonnative cyprinid densities were highest in 1995. The timing of the monitoring-trips was such that during many yeazs crews were sampling nonnative cyprinids that were largely produced the previous year (i.e. Age l+) (see Report C; figure 2), rather than the current year's reproduction. When red shiner CPEs (monitoring data) were regressed against the previous years peak a stronger negative correlation (rz = 0.14) was found. Day et al. (Report B) reported black crappie CPUE was negatively correlated with duration of flow above 75% of the peak (r-2=0.48). Fish Community Monitoring: Large bodied fish -The morphology of the chubs of Deso/Gray canyons is unique relative to what these researchers have seen in Westwater and Cataract Canyons. Many of the chubs handled in Deso/Gray display characteristics of both humpback and roundtail chubs. From the nuchal hump posterior many of these chubs resemble G. cypha: deeply embedded scaling, large falcate fins, often dorsal: anal ray counts of 9:10, slender and elongate caudal peduncles. The head of these "Desolation-type" chubs is more typical of G. robusta: overall blocky in appearance, head is not dished out /concave, snout does not overhang the mouth, and nuchal hump is not pronounced. McElroy and Douglas (1995) and. Douglas et al. (1998) contend that the chubs found in Desolation Canyon can be distinguished to species based on morphological characters. However, they found humpback and roundtail chubs in Desolation and Cataract canyons to be xv