EDITOR'S NOTE: This is 1 of 4 papers from the US Environmental Protection Agency Science Advisory Board's Ecological Processes and Effects Committee workshop on the current and future practice of ecological risk assessment. The workshop was held in Washington, DC in February 2006.

The framework for ecological risk assessments has provided a way to analyze stressors in the environment. Despite the power of this tool to inform environmental management decisions, the practice has not reached its full potential. In this paper, limitations of the practice are described under 2 categories, namely inherent and contrived. Inherent limitations are constraints of nature that we need to be aware of as we design and interpret studies. Contrived limitations are impediments that have arisen in the practice through precedent or policy. The closing portion of this paper provides a series of short-term and long-term steps that could remove some of the limitations, especially the contrived ones, and improve the usefulness of risk assessments.