The relative acute toxicity of chemicals to fish can be categorized as shown in Table 1. The values are derived from laboratory studies and are given only as a guideine and not as absolute values of the toxicity of the chemicals to bluegil or channel catfish. Therefore, in many situations, the actual amount of chemical that will kill fish in a specific body of water may be more or less than the LC50 values given in this publication. Nevertheless, the tables can help you select products that are least likely to have adverse effects on water bodies susceptible to damage resulting from pesticide use. One acre foot equals the volume of water that has an area of 1 surface acre and a depth of 1 foot.
Surface area is determined by multiplying the length by the width.
If you are not sure about applying chemicals to fields adjacent or close to fish ponds, contact your local extension agent for specific information. When chemical applications are made by ground or aerial equipment in the immediate vicinity of water, use low pressure and a spray rate to produce large droplets to minimize drift. Use any other operating practices that will reduce drift. Delay chemical applications in the vicinity of fish ponds until wind is blowing away from the pond. Use chemicals that are least toxic to fish when applying chemicals close to ponds.