A new method of using antimycin to thin overcrowded sunfish populations was tested in five ponds from 2.8 to 8.2 acres in surface area. Concentrations of 0.6 to 1.6 parts per billion of antimycin applied in the shallow upper ends of the ponds removed from 21.0 to 102.1 pounds per acre of sunfishes, but killed almost no largemouth bass of any size. The partial treatment method worked well in every pond in which it was tested despite some wide diurnal fluctuations in pH. Advantages of the new method are: I) applications are based on easily obtained estimates of water volume in the treated area and if the estimate of pond volume is in error either way, this method is likely to give useful results; 2) higher concentrations of antimycin can be used in the treated area, with little likelihood of eliminating all of the small forage fishes from the pond; and 3) there is an increased safety factor and costs of treatment are lower than for whole pond treatments.
