It is important to be able to assess the impacts of multiple stresses on aquatic ecosystems. Although there is now a regulatory requirement in Canada to conduct cumulative effects assessments, there are no widely accepted techniques for accomplishing this. Many of the attempts to examine cumulative effects approach the issue by focusing on the stressors that are involved and their known pathways of impact.
This book approaches the problem from a different perspective, using the performance of fish in the watershed to indicate areas in which performance is compromised by existing conditions. This effects-based approach allows the resident fish to integrate the existing stressors to give insight into the factors affecting performance of the system, thus this opportunity provides a focus for future risk assessments.
The goal of the project was to develop a protocol and framework for undertaking cumulative effects assessments of fish populations. The book describes the methodology and philosophy behind the approach and includes a proposed interpretation framework for decision-making that focuses on sustainability and acceptability of changes rather than the traditional focus on impact assessment.