Consideration of Nontraditional Endpoints in the Assessment of Ecological Risk under the Endangered Species Act

As the field of environmental toxicology progresses, research is revealing effects on species that expand beyond the traditional endpoints of survival, growth, and reproduction as measured in single organism lab studies. Exposure to contaminants can result in adverse effects to endocrine function, olfaction, behavior, and other physiological impairments that may be exacerbated in combination with ecological stressors. Decisions regarding the management of species listed under the Endangered Species Act necessitate an examination of the best available data regarding all the effects of stressors on the conservation of those species, as well as treatment of uncertainty that is inclusive of all potential risks and is commensurate with their protected status. Analysis of potential linkages between sublethal responses of pesticides to higher-order responses in individuals and populations often requires extrapolation of incomplete data sets to provide protection to vulnerable species facing a myriad of potential threats. The adverse outcome pathway model provides a useful framework for the incorporation and use of currently available data, as well as a means to identify vital data gaps to be filled through future research and monitoring.