Michigan Department of Natural Resources
Research and Development Report No. 217
Institute for Fisheries Research Report No. 1772, 1970
The Effects of Methoxychlor on Fishes.
I. Acute Toxicity and Breakdown Studies.
James W. Merna, Michael E. Bender, and James R. Novy
Numerous studies in the last several years (Burdick et al., 1964; Peakall, 1970; Reinert, 1969; and Wurster, 1968) have shown a variety of environmental problems attributable to the widespread use of DDT. Interpretation of these studies, along with aroused public concern, has in some states resulted in either the complete banning of DDT (Abelson, 1969) or in restricting its use to occasions when the public health of an area is endangered (Kramer, 1969). The major compound now recommended, in place of DDT, for the control of such problems as Dutch elm disease is methoxychlor. The reasons for its selection are its: (1) similar potency for many insects; (2) cost is less than many phosphate substitutes; and (3) metabolism by warm-blooded animals is quite rapid (Menzie, 1969). However, virtually nothing is known of its possible effects in the aquatic environment; i.e., no studies have been made on its persistence in natural waters or its chronic toxicity to aquatic animals.
We are conducting a series of experiments designed to determine the potential dangers which may result from increased use of methoxychlor in the environment. These investigations include studies on: (1) the half life of the compound in various aquatic environments; (2) acute bioassay experiments with two species of fish--the fathead minnow (Pimephales promelas) and the yellow perch (Perca flavescens); (3) chronic laboratory and field bioassays utilizing the same two species; and (4) primary productivity experiments with natural phytoplankton populations. In this paper we present data on the first two phases of the study, i.e., breakdown experiments and acute toxicity studies.