Michigan Department of Natural Resources
Research and Development Report No. 226
Institute for Fisheries Research Report No. 1774, 1971
Effects of Dieldrin and Chlordane on Fish in Two Small Streams in Berrien County
James W. Merna
The insecticides, dieldrin and chlordane, were applied to 4,800 acres of Chikaming Township, Berrien County, Michigan, during the period of October 19-23, 1968, to control an infestation of the Japanese beetle. Aerial application of granular material consisted of 2 pounds of technical dieldrin per acre on 3,707 acres, and 10 pounds of technical chlordane per acre on 1,152 acres (Fig. 1). An additional area of 441 acres was treated with chlordane by ground application. A monitoring program was designed to measure the impact of this pesticide application on both terrestrial and aquatic environments.
This report deals with monitoring the aquatic environment. Our primary concern at the start was to collect fish for pesticide analysis of tissue samples. Our second goal was to observe any fish mortality and population reduction, but collected fish were subsequently lost due to failure of a deep-freeze unit, so that this report is now concerned just with direct observations on populations and mortality.