Ecological indicators in risk assessment: Workshop summary

Ecological indicators can be defined as relatively simple measurements that relay scientific information about complex ecosystems. Such indicators are used to characterize risk in ecological risk assessment (ERA) and to mark progress toward resource management goals. In late 1997, scientists from th e U.S. Environmental Protection Agency and from the Chemical Manufacturers Association (CMA) held a workshop to explore opportunities for collaborativ e research and scientific exchange on the development and application of ec ological indicators. Several scientific challenges were identified as they relate to problem formulation, exposure and effects assessment, and risk ch aracterization. Chief among these were a better understanding of multiple s tressors (both chemical and non-chemical), characterization of reference si tes and natural variability, extrapolation of measures to ecologically rele vant scales, development of comprehensive, ecosystem-based models that inco rporate multiple stressors and receptors, and a consistent system for evalu ating ecological indicators.