US EPA

Ecological risk assessment is a process for evaluating the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors. A critical early step in conducting an ecological risk assessment is to select assessment endpoints. Assessment endpoints represent valued ecological entities, and their attributes, upon which risk-management actions are focused. For example, an ecological entity might be an important fish species (e.g., coho salmon), with its attributes being fecundity and survival. Selecting assessment endpoints is often challenging because of the diversity of species, ecological communities, and ecological functions from which those involved in risk assessment can choose and because of statutory ambiguity regarding what is to be protected. The purpose of EPA's document is to assist EPA risk assessors by providing a set of generic ecological assessment endpoints that can be considered and adapted for use in specific ecological risk assessments, building on existing EPA guidance and experience such as the 1998 Ecological Risk Assessment Guidelines. The document is not prescriptive, but rather is intended to be a useful starting point that is flexible enough to be applied to many different types of ecological risk assessments.

This document will be revised after comments from peer reviewers and the public are considered.