Participating Faculty
John Stark
Name:John Stark
Department:WSU Puyallup Research and Extension Center, WSU Puyallup
Credentials:1987~Ph.D., University of Hawaii- Entomology/Pesticide Ecotoxicology
Mailing Address:

Ecotoxicology Program
WSU Puyallup Research & Extension Center
2606 W. Pioneer
Puyallup, WA 98371-4998

Research Interests

John Stark is an ecotoxicologist who specializes in ecological risk assessment of threatened and endangered species. He runs the WSU Salmon toxicology research laboratory and has recently started work on the effects of pesticides on endangered butterfly species. Stark is also a population modeler and has developed population-level risk assessments based on matrix models and differential equation models.

Research Summary

* Development of hazard/risk assessment for aquatic organisms inhabiting rivers and streams in the Pacific Northwest, including salmon and the invertebrates that they feed on as well as biological control organisms inhabiting agricultural ecosystems. Visit the WSU Salmon Toxicology Laboratory information page.

* Effects of pesticides on endangered butterfly species

* Ecotoxicology of pesticides and other toxicants in aquatic and agricultural ecosystems

* Demographic toxicology and modeling impacts on populations.

* Tephritid fruit fly population ecology and control

Research Publications


Hanson. N. and J.D. Stark (2012). Comparison of population level and individual level endpoints to evaluate ecological risk of chemicals. Environmental Science and Technology 46:5590-5598.

Stark, J.D., Chen X.D., and C. Johnson (2012) Effects of Herbicides on Behr’s Metalmark Butterfly, a Surrogate Species for the Endangered Butterfly, Lange’s Metalmark  Environmental Pollution 164: 24-27.

Hanson, N. and J.D. Stark (2012) Utility of population models to reduce uncertainty and increase value relevance in ecological risk assessment: An example with Daphnia exposed to the pesticide spinosad. Integrated Environmental Assessment and Management 8: 262-270.

Banks, J.E., Stark, J.D., Vargas R.I. and A. Ackleh, A. (2011) Parasitoids and ecological risk assessment: Can toxicity data developed for one species be used to protect an entire guild? Biological Control 59: 336-339.

Hanson, N. and J.D. Stark (2011) An approach for developing simple generic models for ecological risk assessments of fish populations. Environmental Toxicology and Chemistry 30: 2372-2383.

*Hanson, N. and J.D. Stark (2011)  Extrapolation from individual level responses to population growth rate using population modeling. Human and Ecological Risk Assessment 17: 1332–1347. Award-Winning paper – HERA “Paper of the Year in Ecological Risk Assessment”

Forbes, V.E., Calow, P., Grimm, V., Hayashi, T.I., Jager, T., Katholm, A., Palmqvist, A., Pastorok, R., Salvito, D., Sibly, R., Spromberg, J., Stark, J.D., and R.A. Stillman (2011) Adding value to ecological risk assessment with population modelling. Human and Ecological Risk Assessment 17: 287–299.

Deardorff, A. D. and J. D. Stark (2011). Population-level toxicity of the insecticide, spinosad and the nonylphenol polyethoxylate, R-11, to the cladoceran species Ceriodaphnia dubia Richard Journal of Environmental Science and Health. Part. B 46(4): 336-340.

Hanson, N. and J. D. Stark (2011). A comparison of simple and complex population models to reduce uncertainty in ecological risk assessments of chemicals: example with three species of Daphnia. Ecotoxicology 20:1268–1276.

Banks, J. E., A. S. Ackleh, et al. (2010). The use of surrogate species in risk assessment: using life history data to safeguard against false negatives. Risk analysis 30(2): 175-182.

Chen, X. D., E. Culbert, et al. (2010). "Mixture effects of the nonylphenyl polyethoxylate, R-11 and the insecticide, imidacloprid on population growth rate and other parameters of the crustacean, Ceriodaphnia dubia." Ecotoxicology and environmental safety 73(2): 132-137.

Chen, X. D. and J. D. Stark (2010). Individual- and population-level toxicity of the insecticide, spirotetramat and the agricultural adjuvant, Destiny to the Cladoceran, Ceriodaphnia dubia. Ecotoxicology 19(6): 1124-1129.

Laetz, C.A., Baldwin, D.H., Hebert, V., Stark, J.D., and N.L. Scholz (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.

Stark, J.D. and R. Vargas (2009) An evaluation of alternative insecticides to diazinon for control of tephritid fruit flies (Diptera: Tephritidae) in soil. J Econ Entomol 102(1): p. 139-43.

Deardorff, A.D. and J.D. Stark (2009) Acute toxicity and hazard assessment of spinosad and R-11 to three cladoceran species and Coho salmon. Bull Environ Contam Toxicol. 82(5): p. 549-53.

Washington State University