NOAA Coastal Storms Program

Ecological Impacts

Articles on current use pesticides

Laetz, C.A., Baldwin, D.H., Collier, T.K., Hebert, V., Stark, J.D., and Scholz, N.L. (2008). The synergistic toxicity of pesticide mixtures: implications for ecological risk assessment and the conservation of threatened Pacific salmon. Environmental Health Perspectives, in press (doi:10.1289/ehp.0800096 available via http://dx.doi.org/). Complex mixtures of pesticides commonly occur in fish habitats. While the toxicity of pesticide mixtures to an important enzyme extracted from fish (in vitro) has been shown to be additive, the effect of mixtures on the enzyme when the entire fish is exposed (in vivo) is not well understood. This study shows that the in vivo toxicity of pesticide mixtures is additive and, in certain combinations, synergistic. Mixtures of pesticides in fish habitats may pose a more important challenge to recovery efforts than previously anticipated.

Scholz, N.L. and Hopkins, W.A. (2006). The ecotoxicology of anticholinesterase pesticides: data gaps and research challenges. Environmental Toxicology and Chemistry, 25:1185-1186. This short article identifies research needs to better understand how common pesticides impact non-target wildlife.

Scholz, N.L., Truelove, N.K., Labenia, J.S., Baldwin, D.H., and Collier, T.K. (2006). Dose-additive inhibition of chinook salmon acetylcholinesterase activity by mixtures of organophosphate and carbamate insecticides. Environmental Toxicology and Chemistry, 25:1200-1207. Stormwater often transports mixtures of pesticides to fish habitats. The toxicity of chemical mixtures to aquatic species is a complex problem that is still poorly understood. This study shows that the toxic effects of the individual components of pesticide mixture are additive in terms of their inhibition of an important enzyme extracted from the salmon nervous system.

Stehr, C.M., Linbo, T.L., Incardona, J.P., and Scholz, N.L. (2006). The insecticide fipronil causes notochord degeneration and locomotor defects in zebrafish during early development. Toxicological Sciences, 92:270-278. Fipronil is among a newer generation of insecticides that have been specifically designed to target key elements of the insect nervous system. This study reveals that fish embryos are sensitive to fipronil, and that a novel mechanism may be involved in the observed developmental toxicity.

Sandahl, J.F., Baldwin, D.H., Jenkins, J.J., and Scholz, N.L. (2005). Comparative thresholds for acetylcholinesterase inhibition and behavioral impairment in coho salmon exposed to chlorpyrifos. Environmental Toxicology and Chemistry, 24:136-145. Chlorpyrifos is a common insecticide in runoff to fish habitats throughout the United States. This study links low, environmentally realistic chlorpyrifos exposures to impaired brain chemistry and behavior in juvenile salmon. The findings suggest that the feeding and growth of salmon may be inhibited under environmental exposure conditions.