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VI. Discussion A. Reservoir During 1993-97, 259 stocked channel catfish were captured. When captured, each fish was marked with a pectoral spine clip. Seventeen of these fish were recaptured in 1993-95. They in turn were given another pectoral spine clip and released. No fish with two spinal clips were recaptured during the study. No fish with spinal clips were recaptured in 1996-97. Over the period 1993-97, 19 unmarked channel catfish of wild origin were captured from Kenney Reservoir. Using the ratio of 259/3,000 to 19/x, and assuming similar mortality rates, the wild channel catfish population in the reservoir at the beginning of the study was 220. Thus about 7% of the reservoir channel catfish population was of wild origin. It is believed these wild fish were trapped in the reservoir when Taylor Draw Dam was constructed or by being illicitly stocked by fishermen. It is unlikely natural reproduction is occurring. If it was occurring, there would be small fish appearing in the catch. The smallest wild channel catfish captured was 230 mm TL, and only four fish less than 300 mm TL were taken in five years. O'Shea and Hubert (1991) reported that channel catfish need a 120 day growing period in Wyoming for natural reproduction to successfully maintain the population. The growing season in the Kenney Reservoir area is 105 to 130 days (Alvin Jones, Natural Resources Conservation Service, personal communication, February 25, 1997). In seining studies offish in the White River from the Kenney Reservoir area downstream to Utah, Martinez (1986), Chart (1987), and Trammell (1991) found only one young-of--year channel catfish. The stocked channel catfish population in Kenney Reservoir is estimated at 757 fish in 1995 by using the Schnabel estimator (Table E-1). In using this model the numbers of marked fish in the population were decreased by 10% at the beginning of each year to account for mortality, possible loss of Floy tags, and possible regeneration of spinal clips. This population estimate may be low because so few recaptures were used in the model. When the model was run with hypothetically increased recaptures, the population estimate likewise increased. Also, the low recapture numbers for all species (Table 2) implies a low sampling efficiency. The estimate of 757 fish is 25% of the 3,000 fish originally stocked. This is a 63% annual survival rate for 1992-95. It compares with survival rates at other established channel catfish sportfisheries. O'Shea and Hubert (1991) used a 75% survival rate to compute channel catfish numbers in Wyoming reservoirs, and Elrod (1974) calculated annual channel catfish survival rates at 50%-70% for different age classes over a number of years at Lake Sharpe, South Dakota. Backcalculated mean TL at age for stocked Kenney Reservoir channel catfish are compared to mean backcalculated TL at age for other channel catfish populations (Table 5). Kenney Reservoir fish were age 1 when stocked in 1992. Growth rates for Kenney Reservoir fish are comparable to or better than those observed at the other waters. The measured mean TL for Kenney Reservoir 13