LARRY COFER, GARLAND WRIGHT, HUTCHIE WEEKS, AND LONNIE COOK, Oklahoma Department of Wildlife Conservation, HC 32, Box 580, Lawton, Oklahoma 73501, USA

Long-term stockings of 75- TO 125-mm channel catfish were ineffective at increasing catfish populations in Oklahoma reservoirs, based on pre- and post-stocking gill net evaluations. Beginning in 1993, channel catfish were raised to 175-mm in one growing season (June through October) by stocking fry at lower densities in hatchery ponds (30,000/ha). Objective criteria were established for stocking catfish in Oklahoma reservoirs, and lake stocking densities were reduced to evaluate survival of 175-mm channel catfish. Stockings of these advanced fingerlings for 2-3 years in 14 reservoirs (10 to 2560 surface-hectare ) significantly increased channel catfish catch rates in gill nets in 13 cases, and met a goal of raising populations to above the state average in 12 cases. Gillnet catch improvements persisted as catfish recruited to the fishery (>300 mm) following stockings. A reduction in the relative weight of channel catfish was noted in some lakes, and alternate-year stockings or reduced stocking densities were implemented to improve condition. Based on these results, existing reservoirs with below-average populations receive 175-mm channel catfish in Oklahoma, and stockings of smaller fingerlings are now limited to new impoundments.