Factors Affecting Blue Catfish Populations in Texas Reservoirs
Brian L. Bartram, John E. Tibbs, and Patrick D. Danley
Abstract.—The blue catfish Ictalurus furcatus is the largest ictalurid in the United States and is present in many reservoirs throughout Texas. While some populations are native, many fisheries are the result of introductions through stocking programs. These stockings can result in established fisheries while others fail to produce established populations. It is possible that a combination of physical, chemical, and biological variables produce an ideal environment for the successful establishment and survival of this species. The objective of this study was to identify the key factors that influence the success of blue catfish populations in Texas reservoirs. Thirty reservoirs distributed across Texas were sampled using gill nets and low-frequency electrofishing. Blue catfish abundance, condition, and natural reproduction were compared with multiple physicochemical and biological variables collected at each reservoir. Factor analysis indicated that both gill-net catch rates and low-frequency electrofishing catch rates were positively correlated to measures of primary productivity. The analysis also showed that gill-net catch rates increased with increasing reservoir surface area. The occurrence of natural reproduction showed a weak negative correlation to length of growing season. The results of this study provide further insight into the biology of blue catfish and provide managers with information that can be used to prioritize future stocking efforts.