Background and Justification

The flathead catfish, Pylodictis olivaris, has been introduced to Atlantic slope rivers in the southeastern U.S. Given its rapid dispersal and growth rates and carnivorous food habits, fishery managers and anglers have been concerned with the impacts that introduced flathead catfish may exert upon native fish assemblages and fisheries. Of special concern is the observed decline in native redbreast sunfish, Lepomis auritus, populations associated with increases in flathead catfish. This conflict between native and introduced sport fisheries creates a management dilemma that requires sound, quantitative information, upon which to base management strategies. Fisheries managers and researchers agree that management efforts and public education are limited by a lack of sound, quantitative information for guidance, and that management efforts could be improved with comprehensive, systematic research findings.

Objectives

The goal of this research is to gain an understanding of population dynamics, predator-prey relations, and other aspects of flathead catfish biology and ecology to develop empirical relationships to estimate changes in fish population dynamics and assemblage structure associated with introduced flathead catfish occurrences. Specific objectives are to

(1) determine flathead catfish population density, biomass, and associated statistics;

(2) quantify individual growth rates and size and age structure of flathead catfish populations;

(3) estimate flathead catfish migration rates in rivers; and

(4) determine flathead catfish diet, feeding intensity, and feeding selectivity.

Results of this ongoing research may be used to increase public awareness of facts and to guide physical and biotic manipulations and other management actions to improve resource management strategies.

For details of results, see

Waters, D.S., T.J. Kwak, J.B. Arnott, and W.E. Pine. 2004. Evaluation of stomach tubes and gastric lavage for sampling diets from blue catfish and flathead catfish. North American Journal of Fisheries Management 24: 258-261.

Pine, W.E, III, T.J. Kwak, D.S. Waters, and J.A. Rice. 2005. Diet selectivity of introduced flathead catfish in coastal rivers. Transactions of the American Fisheries Society 134: 901-909.

Bringolf, R.B., T.J. Kwak, W.G. Cope, and M.S. Larimore. 2005. Salinity tolerance of flathead catfish: implications for dispersal of introduced populations. Transactions of the American Fisheries Society 134: 927-936.

Kwak, T.J., W.E. Pine, III, and D.S. Waters. 2006. Age, growth, and mortality of introduced flathead catfish in Atlantic rivers and a review of other populations. North American Journal of Fisheries Management 26: 73-87.

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