Most likely your next step would be to call your favorite fisheries professional discuss your day and schedule an electrofishing survey. Weeks later during the survey your fears are confirmed and there really are way to many crappie, green sunfish, and largemouth bass in the lake. Also, you find that your entire forage fish population is based on larger gizzard shad. Just when you think it could not get any worse you notice a few small black catfish that turn out to be mudcat. At this point you know and the fisheries biologist knows this is bad. After the survey the biologist tells you about the different fish species and what they all mean to the fishery. He then says the words you fear most " You should start over". Basically the biologist is telling you that the lake has many fish species which make achieving your goal difficult. Combined they make it nearly impossible. You may with time, tons of effort, and a large budget make small improvements but the only way to reach your goal is to start over.
Considering the facts that rotenone restricts cellular ability to absorb oxygen and dissolved oxygen is lowest in warm water it is most often recommended to apply the chemical during hot summer days. Many fish species will have lower oxygen tolerances and therefore a slightly higher tolerance to rotenone concentrations. Rotenone is applied by mixing the chemical with water and distributing it at multiple depths to cover the entire water body evenly. The amount of rotenone to be used is based on the acre-ft of water currently in the lake. Many times lake owners will pump water levels down to save on time to apply and chemical needed. Depending on the concentration of rotenone used fish can be restocked into the water body within 4-6 weeks and you can get back to achieving your goals with a fresh start.
Steven Bardin M.S.