Eliminating Fish Prior to Stocking
When construction is completed, but before the pond is full, all wild fish should be eliminated from any water existing in the pond or watershed. Assume that fish are present even if none are seen. The elimination of all fish from the pond and watershed is one of the most important steps toward successful fishing. Suckers, shad, bullheads, green sunfish, shiners, and other fish will spawn in a pond and compete with stocked fish for food and space, much like weeds in a vegetable garden. The production of desirable fish will be greatly reduced, and pond failure is likely if wild fish are not eliminated.
The time of year that wild fish are eliminated is important. The work should be done after October 1, but before January 10, if fish are to be obtained from Alabama’s Division of Wildlife and Freshwater Fisheries. If it is necessary to complete construction during the period of March to September, allow the valve to remain open until October or drain the pond at this time and treat all potholes and other water with rotenone to eliminate all fish. Before treatment, the pond valve must be closed so that fish will not be killed downstream.
Powdered or liquid formulations that contain 5% rotenone or its equivalent should be used to eliminate fish in the pond and watershed area. Rotenone is not dangerous to livestock when used as directed. Before application, mix the powdered material thoroughly with water until a “soupy” mixture is obtained. Liquid formulation of rotenone should be diluted with sufficient water to adequately treat all of the pond basin and watershed.
The amount of rotenone to apply will vary widely depending upon the site. Therefore, label instructions should be followed closely regarding application rates. Basically, all standing water should be treated with 10 pounds of powder or 10 pints of liquid rotenone per acre-foot of water (acre feet = surface acres X average depth). Ten pounds or 10 pints of material containing 5 percent rotenone should be applied for each ¼ mile of stream that averages up to 1 foot in depth and 10 feet in width. A second treatment is often necessary to eliminate all fish.
Rotenone is a restricted use pesticide and cannot be purchased without a valid permit. The local county extension agent should be contacted to obtain current label information regarding the purchase and application of rotenone. Label instructions should always be followed when making a treatment.