Abundance, Growth, and Mortality of the Lake Texoma Blue Catfish Population: Implications for Management

The blue catfish Ictalurus furcatus fishery at Lake Texoma has been increasing in popularity. Guides that typically seek striped bass Morone saxatilis switch to blue catfish, particularly during the winter months when the largest individuals are most vulnerable. Low frequency electrofishing samples, collected since the early 1990s by the Oklahoma Department of Wildlife Conservation, indicate that population abundance is stable but concerns have been raised over the long term viability of the fishery in the face of increased angling pressure on the largest individuals. Baseline age and growth data, using otoliths, were collected from both the Red River arm and Washita River arm in 2003 (N = 333). Mortality rates were estimated using the Fishery Analysis Simulation Tools model. Growth rates, particularly of fish age ? 6, were highly variable. The oldest fish collected was age 16 and weighed 20.43 kg. Growth rates of the smaller individuals (ages 1, 3, 4, 5) were higher in the Red River arm than in the Washita River arm. No differences were found in growth rates of older fish, likely due to the high variation in mean length at age. Blue catfish from Lake Texoma reach 762 mm (4.5 kg) in approximately 12 years. Total annual mortality estimates (A) from the Red River arm and Washita River arm were 13.5% and 17.0%, respectively (A = 18.8% for both arms combined). Even though these mortality estimates are low relative to that of other freshwater sport fishes, given the length of time it takes to reach a size being targeted by guides and their clients, options to limit harvest of large blue catfish may need to be considered in the future.

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