Toxicity of the Insecticide Dursban^(R)to Fish and Aquatic Invertebrates in Ponds

Abstract

Bluegills (Lepomis macrochirus Rafinesque) and largemouth bass (Micropterus salmoidesLacepede) were exposed to two applications of Dursban©, an organophosphorus insecticide, at the recommended rates for mosquito control of 0.05 or 0.01 lb of active ingredient/A in experimental 0.! acre ponds. Residues of Dursban in water ! day after the applications ranged from 2.39 parts per billion (ppb) in the highest treatment to 0.97 ppb in the low treatment. Cumulative mortality in the untreated ponds during 63 days of observation was approximately 1% of the total population of each species of fish. Cumulative mortality of fishes during the same period in ponds treated at 0.0! lb/A was 3% for bluegills and 10% for bass, whereas the corresponding mortalities for the high application rate (0.05 lb/A) were 55% for bluegills and 46% for bass. Uptake of Dursban by fishes produced maximum residue values of 3.82 parts per million (ppm) in bluegills and 2.55 ppm in bass within ! to 3 days after application of the insecticide at 0.05 lb/A. These residues decreased greatly within 2 weeks to less than 0.4 ppm and were undetectable after 4 weeks. Both species of fish taken from the ponds treated at 0.05 lb/A exhibited more than 80% inhibition of brain acetylcholinesterase activity as compared to fish from untreated ponds; fishes from these ponds had not recovered normal acetylcholinesterase activity 28 days after application of the insecticide. Histological examination of tissues from bluegills and largemouth bass exposed to Dursban did not show conclusive evidence for pesticide-induced pathology. The high treatment reduced the total number of insects colonizing plate samplers by three-fourths, eliminated caddisflies, and severely reduced mayfly populations. We believe that the results of this investigation confirm the inadvisability, as suggested on product labels, of using Dursban at the current recommended rates of application for mosquito control in habitats where valuable fishery resources are to be protected. SMITH, G. 1966. Basic studies on Dursban insecticide. Down to Earth 22(2): 3-7. Dow Chemical

An experimental manipulation of oligochaete communities in mesocosms treated with chlorpyrifos or nutrient additions: multivariate analyses with Monte Carlo permutation tests

“…By contrast several which suggests that the ditches are still in an early other studies showed no direct effects on oligochadevelopmental stage. This also explains the di-etes (Macek et al, 1969;Nelson & Evans, 1973). Although secondary effects, between 14 and 56 days after treatment, are suggested by van Wijngaarden & Leeuwangh (1989) who reported that oligochaetes decreased in numbers or even vanished.…”

Profenofos Residues in Wild Fish from Cotton‐Growing Areas of New South Wales, Australia

“…Prolonged AChE inhibition has been found in fish exposed to several organophosphorus insecticides. Macek et al (1972) found that after treatment of ponds with chlorpyrifos at 0.056 kg/ha, brain AChE activity of bluegills and largemouth bass was inhibited by 80%, and did not return to the levels of control fish until 28 d after pulse addition of the pesticide. Enzyme activity in brains of spot remained significantly below pre‐spray levels for more than 40 d after spraying of malathion (Coppage et al, 1975).…”

Sub-lethal effect of cypermethrin on acetylcholinesterase (AChE) activity and acetylcholine (Ach) content in selected tissues of Channa striatus (Bloch.)

“…The inhibition of AChE activity is directly related to the concentration of pesticides and the length of exposure (Coppage, 1972;Macek et al, 1972). Koundinya and Ramamurthy (1979) also reported a greater inhibition in AChE activity, with higher elevation in ACh content in the brain than in the muscle of T. mossambica exposed to sumithion.…”