The issue of significance in ecological risk assessments

Significance in ecological risk assessments is a meta-issue that involves all phases of the risk assessment process from the setting of goals and the identification of endpoints to the use of criteria for evaluating the importance of predicted change in the ecological endpoints. Sustainability has been chosen as the management goal and context for interpreting significance because it integrates ecosystem properties with public values and uses. This explicitly recognizes the inevitability of the human-environment interaction, which is operationally defined through the identification of endpoints and measures to be used in the risk assessment. Criteria (e.g., variability, recovery/reversibility, spatial scale, temporal scale, and magnitude [severity] of change), and two decision frameworks are presented for evaluating the importance of changes in ecological endpoints using expert judgement or by quantifying or scaling the criteria. To implement this approach fully will require research in the following areas: (1) identifying characteristics or attributes (generic and specific) of ecosystems that reflect sustainability; (2) improving methods for identifying and incorporating public values into the process of valuing ecological resources; (3) quantifying the significance criteria; and (4) providing policy guidance. © 1998 by ASP.