Abstract
Limited toxicity data are available for estuarine and marine species and the widely used pyrethroid insecticide, permethrin. This study determined acute effects of permethrin on survival, lipid peroxidation, acetylcholinesterase activity, and splenocyte proliferation for two fish species found in South Carolina estuaries; juvenile red drum (Sciaenops ocellatus) and adult mummichog (Fundulus heteroclitus). Juvenile S. ocellatus were significantly more sensitive than adult F. heteroclitus to permethrin exposure, with a 96-h LC50 value of 8 μg/L determined for red drum compared to 23 μg/L for mummichog. Lipid peroxidation activity of the liver increased in permethrin-treated fish compared to control animals after 24 h and decreased after 96 h. Permethrin had no effect on acetylcholinesterase activity of the brain at the concentrations tested. Permethrin exposure significantly inhibited splenocyte proliferation, indicating an immunosuppressive effect. Most of the effects of permethrin on fish cellular stress enzymes and survival occurred at concentrations much higher than those typically measured in the environment. However, inhibition of splenocyte proliferation in juvenile red drum occurred at approximately twice that of measured permethrin concentrations in surface water. These findings may prove useful to the future management and regulation of pyrethroid insecticide use near estuarine habitats.
Acknowledgments
The authors wish to thank Karen Burnett and William Roumillat for experimental advice, Katy Chung, Blaine West, John Venturella and Pete Key for laboratory assistance, and Mike Denson and staff of the SC Department of Natural Resources Waddell Mariculture Center for collection and donation of the juvenile red drum. Dr. Yelena Sapozhnikova, NOAA, provided the chemical analysis. Fish bioassay protocols were approved by the College of Charleston Institutional Animal Care and Use Committee (IACUC-2009–022). The NOAA, National Ocean Service (NOS) does not approve, recommend, or endorse any proprietary product or material mentioned in this publication.