Fish Populations in the Backwaters of Wheeler Reservoir and Suggestions for their Management

Abstract

During the past 3 years, several methods have been used in an effort to determine the standing crop of fish and the relative abundance of the different species in the fish population of Wheeler Reservoir. In addition to a census of sport and commercial fishing, gillnets, set lines, seines, fyke nets, and rotenone have been used to sample the fish population. Among the methods used, poisoning with rotenone has proven to be the most effective. When sampling the fish population by this method, areas of the reservoir which were suitable for study were shut off by means of a barrier seine before the rotenone was applied. This procedure made it possible to determine the total fish population and the relative numbers and weights of each species without allowing the poison to spread or fish to migrate to or from the area. Three plots having a combined area of 12 acres were treated in this way. It was found that of the total weight of fish taken in the three areas, game fish comprised from 2 to 4 per cent; panfish 7 to 19 per cent; food fish 3 to 6 per cent; and coarse fish 73 to 85 per cent. Coarse fish, such as carp, buffalo, and shad, were dominant in the population of all areas. It is concluded that the desirable species, such as black bass, must be encouraged in all possible ways and the coarse species controlled by all means at hand, if game fishing is to be maintained. As an experiment, it is planned to screen off an area having a narrow connection with the main reservoir so that all fish can be removed by the use of rotenone and the area restocked with desirable species. It is blieved that by removing the coarse species which now comprise about 73 to 85 per cent of the total weight of fish present, the total productive capacity of the water will be used in the production of desirable species and the yield of these species will be greatly increased, which will greatly benefit sport fishing.