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types and interaction between dates and vegetation types (Table 2). Red shiners appeared more abundant in open waters, whereas carp were more abundant in emergent vegetation (Figure 13). Green sunfish collected in fyke nets showed differences among dates. The number of age-O carp caught in clover-shaped minnow traps was nearly significant (P= 0.056) among vegetation types (Table 2), again suggesting that fish may have avoided open water (Figure 13). A significant difference was also observed between the number of fathead minnows collected in clover-shaped minnow traps collected over time. Red shiners were captured in significantly higher numbers in deeper water fyke net sets (Table 3, Figure 14). Significant differences in age-O carp were detected among depth, with most fish collected less than 0.75 m. Significant differences were detected in numbers of age-O carp caught in minnow traps with most fish captured in depths between 0.5 m and 1.50 m (Figure 14). Differences were also detected in depth x date interaction for all species tested for clover-shaped minnow traps and dates for all species but fathead minnows (Table 3). Methods Chapter Three: Fish Census and Wetland Draining The total number offish using Old Charley Wash was determined in the fall of 1994 and 1995, and summer of 1996. Census was accomplished by completely draining the wetland and concentrating fish in the lower end of the drainage canal near the outlet structure where they were collected with seines. In the spring of each year the water control structures on the outlet dike were closed. In 1994, although water did not flood over the dikes, water pressure on the outlet water control structure during the peak spring flood eroded substrate under the stop-log drain and allowed access to fish from the river for several days before the leak was stopped. When the wetland was connected directly to the river during the high flow years of 1995 and 1996, fish from the Green River had direct access to the wetland. The inlet canal culvert accessing the wetland to the river was open during each year of the study and was equipped with a 13 mm screen to minimize access of large fish into the wetland. The wetland was drained using the water control structure at the outlet structure. During the draining process a 6.4 mm screen was secured on the inside of the outlet drain corridor to prevent fish from leaving the wetland as it drained. In April 1995 the outlet structure of Old Charley Wash was modified by adding a second lower dike with a water control valve. The modified outlet structure allowed fish to be collected from the drainage canal prior to complete draining of the wetland. Draining was completed from 17 October to 10 November in 1994,25 September to 12 October in 1995, and 17 July to August 18 in 1996. Fish collections were made between 17 October and 10 November 1994. During 1995 and 1996, collections were made two to three times a week after initiating draining. During the last week of draining, the number of fish congregating at the outlet required collection every day of the week during both 1995 and 1996. During 1994, two factors prevented a complete census of fish in the wetland. The first included steep muddy banks, thick muddy bottom, and the accumulation of vegetation at the bottom end of the drainage canal that made it difficult to collect fish. Fish easily evaded capture attempts by seines. Because of these conditions, seines smaller than 13 mm mesh were not efficient. A second factor included the erosion damage that allowed fish access in the spring, which allowed unknown fish access out of the wetland. As a result, the fish collected during the draining do not represent all fish present prior to draining. 29