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Gmean CPE for Colorado squawfish in each reach was correlated with flow pazameters that occurred in that reach for that year. Gmean CPE and mean total length of Colorado squawfish were correlated with accumulated temperature units for the yeaz to evaluate relations between abundance or growth and temperature. Average high flow was correlated with accumulated temperature units to examine the effect of runoff on river wazming. Habitat use of YOY Colorado squawfish was evaluated using independent t-tests, analysis of vaziance (ANOVA), and simple correlation. Independent t-tests compazed differences in water temperature (actual temperature of the backwater as well as temperature difference between the backwater and the main channel), backwater surface azea and maximum depth of backwaters that contained at least one YOY Colorado squawfish with backwaters that did not contain any. Histograms compazing the relative distribution of all types of backwaters sampled with the relative distribution of backwaters that contained at least one Colorado squawfish were developed. CPE in backwaters that contained Colorado squawfish was correlated with backwater temperature, backwater size, and maximum depth to evaluate correlations among the different pazameters. ANOVA was used to compaze differences in gmean CPE among four categories of the pazameters mentioned above. The backwaters were split into the four categories based on the distribution of each parameter over the course of the monitoring program. Each of the four categories roughly corresponded to 25% of all observations of this parameter over the 7 yeazs. These categories aze: maximum depth (cm)- < 35, 35 to 49, 50 to 76, and > 76; surface area (rr~- < 350, 350 to 649, 650 to 1349, and > 1349; temperature (°C)-9-15, 16-19, 20-23, and 24-32; and temperature difference (°C; only three categories were used)--5 to -1, 0 to +3, and +4 to + 18. Significant differences identified with ANOVA were further evaluated with Tukey's HSD (honestly significant difference) procedure. All analyses were partitioned by reach and year to avoid confounding results by differences in abundance among yeazs and reaches. All data manipulations and analyses were performed with dBASE and SYSTAT softwaze packages. Results River Flows and Water Temperatures River flow was highest in 1986 of all years sampled during ISMP (Table D-1; Figures D-1 through D-6) in both the Green and Colorado rivers. Flow peaked at 34,100 cfs in the lower Colorado River and 35,400 cfs in the lower Green River (Table D-1). Runoff was almost as high in the Colorado River in 1987 (30,500), but was considerably reduced in the Green River in 1987 (13,600). Maximum river flow in the Colorado River in subsequent years was 14,300 in 1988, 9,670 in 1989, 12,200 in 1990, 18,400 in 1991, and 17,100 in 1992. Yearly maximum flow in the Green River from 1988 through 1992 was 16,900, 7,840, 11,000, 12,400, and 10,700 respectively. Flows throughout each yeaz, including the fall sampling period, generally followed the same pattern as spring runoff. Flows were highest in 1986, lowest in 1989, and somewhere in the middle during other yeazs (Tables 2, B-2, and D-1). Water temperatures in both the Green and Colorado rivers generally reflected the runoff patterns established during spring. Warming was slow in 1986 because the large volume of runoff delayed wazming (Table B-3) and faster during the lower water yeazs. Accumulated temperature units were negatively correlated with average high runoff (mean of flows 15 days before and 15 days after the highest flow of the yeaz) except for temperatures exceeding 20°C in Reach 2. As would be expected because of increased exposure to warmer air temperatures as the water moved downstream, river 7