Northwest Fisheries Science Center

Ecotoxicology Research Areas


Dr. Nat Scholz
Program Manager
Staff Directory


For more than a decade, the Ecotoxicology Program has been studying the impacts of current use pesticides (biocides) on the health of juvenile salmon and their freshwater habitats. The science is intended, in part, to address important information gaps specific to NOAA's protected resources, such as threatened and endangered species. The work has focused primarily on insecticides that are potentially toxic to salmon and the terrestrial and aquatic insects they eat. Recent research has addressed sublethal impacts on salmon behavior, the toxicity of pesticide mixtures, interactions between pesticides and non-chemical habitat stressors, and adverse effects that scale from individual salmon to populations. This research area is sponsored by NOAA Fisheries' Office of Protected Resources.

Program Contact

Nat Scholz

Project Staff

Mary Arkoosh, David Baldwin, Joe Dietrich, Barbara French, John Incardona, Jana Labenia, Cathy Laetz, Tiffany Linbo, Nat Scholz, Julann Spromberg


NOAA Fisheries, Office of Protected Resources
Washington State University, Puyallup Extension Campus


Laetz, C.A., Hecht, S.A., Incardona, J.P., Collier, T.K., and Scholz, N.L. 2015. Ecological risk of mixtures. In: Aquatic ecotoxicology: advancing tools for dealing with emerging risks. C. Amiard-Triquet, J.-C. Amiard, and C. Mouneyrac (eds). Academic Press, pp. 441-462.

Macneale, K.H., Spromberg, J.A., Baldwin, D.H., and Scholz, N.L. 2014. A modeled comparison of direct and food web-mediated impacts of common pesticides on Pacific salmon. Public Library of Science ONE, 9: e92436.

Dietrich, J.P., A.L. Van Gaest, S.A. Strickland, M.R. Arkoosh. 2014. The impact of temperature stress and pesticide exposure on mortality and disease susceptibility of endangered Pacific salmon. Chemosphere, 108:353-359.

Laetz, C.A., Baldwin, D.H., Hebert, V.R., Stark, J.D., and Scholz, N.L. 2014. Elevated temperatures increase the toxicity of pesticide mixtures to juvenile coho salmon. Aquatic Toxicology, 146:38-44.

Jorgenson, B., Brown, L., Fleishman, E., Macneale, K.H., Schlenk, D., Scholz, N.L., Spromberg, J.A., Werner, I., Weston, D., Young, T.M., Zhang, M., and Zhao, Q. 2013. Predicted transport of pyrethroid insecticides from an urban landscape to surface water. Environmental Toxicology and Chemistry, 32:2469-2477.

Laetz, C.A., Baldwin, D.H., Stark, J.D., and Scholz, N.L. 2013. The interactive neurobehavioral toxicity of diazinon, malathion, and ethoprop to juvenile coho salmon. Environmental Science and Technology, 47:2925-2931.

Scholz, N.L., Fleishman, E., Brooks, M.L., Mitchelmore, C.L., Werner, I., Johnson, M.L., Schlenk, D., and Brown, L. (2012). A perspective on modern pesticides, pelagic fish declines, and unknown ecological resiliency in highly managed ecosystems. BioScience, 62:428-434.

Weston, D.P., Asbell, A.M., Hecht, S.A., Scholz, N.L., and Lydy, M.J. 2011. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest. Environmental Pollution, 159:3051-3056.

Macneale, K.H., Kiffney, P.M., and Scholz, N.L. 2010. Pesticides, aquatic food webs, and the conservation of Pacific salmonids. Frontiers in Ecology and the Environment, 9:475-482.

Stehr, C.M., Linbo, T.L. Scholz, N.L., and Incardona, J.P. 2009. Evaluating effects of forestry herbicides on fish development using zebrafish rapid phenotypic screens. North American Journal of Fisheries Management, 29:975-984.

Baldwin, D.H., Spromberg, J.A., Collier, T.K.,and Scholz, N.L. 2009. A fish of many scales: extrapolating sublethal pesticide exposures to the productivity of wild salmon populations. Ecological Applications, 19:2004-2015.

Laetz, C.A., Baldwin, D.H., Collier, T.K., Herbert, V., Stark, J., and Scholz, N.L. 2009. The synergistic toxicity of pesticide mixtures: implications for ecological risk assessment and the conservation of threatened Pacific salmon. Environmental Health Perspectives, 117:348-353.

Labenia, J.S., Baldwin, D.H., French, B.L., Davis, J.W., and Scholz, N.L. 2007. Behavioral impairment and increased predation mortality in cutthroat trout exposed to carbaryl. Marine Ecology Progress Series, 329:1-11. (Feature Article)

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.

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.

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.

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.

Sandahl, J.F., Baldwin, D.H., Jenkins, J.J., and Scholz, N.L. 2004. Odor-evoked field potentials as indicators of sublethal neurotoxicity in juvenile coho salmon exposed to copper, chlorpyrifos, or esfenvalerate. Canadian Journal of Fisheries and Aquatic Sciences, 61:404-413.

  • Common pesticides disrupt salmon behavior by interfering with synaptic signaling (cholinergic neurotransmission) in the brain.
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