A traffic light decision system for marine finfish aquaculture siting

Abstract

A decision support system (DSS) is described to assess far- and near-field variables potentially affected by marine finfish aquaculture. The DSS consists of 20 questions that produce positive to negative scores for ecosystem-level (far-field) and site-specific (near-field) variables based on pre-determined or proposed qualitative criteria and known or proposed threshold values for variables. A Traffic Light Method indicates scores above (A; dark green), intermediate to (B+; light green or B−; orange) or below (C; red) criteria for acceptability. Some variables are pre-emptive if scored C. Cumulative ecosystem and site indices are calculated and assessed in a conventional three-color Traffic Light scheme as acceptable (green), provisionally acceptable (caution required) (yellow) or unacceptable (red) using a decision matrix of all possible color combinations. The DSS is flexible since new questions can be added, scores for selected variables can be weighted, and revised thresholds can be incorporated to reflect additional scientific information, changes in aquaculture licensing regulations or specific jurisdictional requirements. Data from salmon farm license applications in eastern Canada are tested using the DSS.