This book presents the proceedings of the 19th Pellston Workshop held in Pellston, Michigan from 23-28 August 1994 at the University of Michigan Biological Station, the site of many workshops since the Pellston series began in 1977. Similar to other workshops in this series, expert participation was invited from government, academia, public interest groups, and industry. Invited participants were selected based on thier demonstrated interest and experience concerning ecological risk assessment, development of decision-support systems, or both. The workshop provided an organized format for exchanging ideas, debate, and development of consensus concerning the many unresolved issues associated with the application of ecological risk assessment and the conceptual design of a decision-support system. These proceedings reflect the state-of-the-art at the time of the workshop and focus on the components of ecological risk assessment and on their possible integration into a conceptual design for a decision-support system. Potential approaches toward realizing this vision were explored at the workshop and are outlined in this volume.