Effects of the synthetic pyrethroid insecticide, permethrin, on two estuarine fish species

Pesticides can enter coastal waters via posing a risk to non-target aquatic species. Permethrin is a synthetic pyrethroid insecticide used in various settings to control insect pests. This study examined the effects of permethrin on two species of fish found in South Carolina estuaries, the red drum ( Sciaenops ocellatus), and the mummichog (Fundulus heteroclitus ). The 96h LC50, NOEC, and LOEC of permethrin were determined for both species representing different size classes. Sublethal cellular stress effects of permethrin were also assessed. Lipid peroxidation activity of the liver was significantly higher in permethrin-treated fish compared to control animals after 24h and significantly lower after 96h. Permethrin had no effect on liver somatic index, or on acetylcholinesterase activity of the brain at the concentrations tested. Permethrin exposure (96h) significantly inhibited splenocyte proliferation. Most of the effects of permethrin on fish cellular stress enzymes and survival occurred at concentrations higher than those measured in the environment. These findings will further understanding of the effects of permethrin on estuarine organisms and may prove useful to the future management and regulation of pyrethroid insecticide use near estuarine habitats.