An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Ecotoxicological Assessment & Monitoring

Wetland landscape

EPA researchers are developing, integrating, and evaluating ecological models to predict effects of pesticides and other chemicals on endangered species and wildlife populations. High-level assessments include quantitative estimates of ecologically-relevant risk and identification of risk mitigation options. The majority of chemicals have little or no data on which to base these decisions. For these chemicals, risk assessments rely on ecological models to estimate exposure and subsequent effects. 

Tools and Resources

  • ECOTOX - Provides information on adverse effects of single chemicals to ecologically relevant aquatic and terrestrial species. It includes more than 780,000 test records covering 12,000 aquatic and terrestrial species and 11,000 chemicals.
  • SeqAPASS - Extrapolates from data rich model organisms to thousands of other non-target species to evaluate potential chemical susceptibility.
  • Markov Chain Nest Productivity Model - Estimates the impact of pesticide exposures on the reproduction success of bird populations. 
  • Markov Chain Nest Productivity Model Estimating Tool- Estimates probabilities of failure of avian reproduction in the presence of competing risks. 
  • Web Ice - Estimates acute toxicity to aquatic and terrestrial organisms for use in risk assessment.
  • Species Sensitivtiy Distribution (SSD) Toolbox - A tool that helps chemical scientists, assessors and regulators understand chemical concentrations in surface waters.