An approach for assessing and ranking fisheries management scenarios in spatially delimited marine areas

Spatial restrictions to human activities such as bottom trawling are increasingly used to improve the ecological condition of disturbed habitats. Such management interventions typically have socio-economic consequences, which creates a challenge for those making decisions about which activities should be restricted and where restrictions should apply. We present an approach for predicting the effects of fisheries management scenarios in spatially delimited marine areas and ranking them—using a loss function—according to how well they achieve desired outcomes across a set of ecological and socio-economic indicators. This approach is demonstrated by simulating alternative fishing gear restrictions and zoning options within a hypothetical marine protected area (MPA). Relative benthic status (RBS; an indicator of ecological condition) and relative catch value (RCV; an indicator of potential economic cost) were estimated for the baseline environment and 21 potential management scenarios. The rank order depended on which indicator was prioritized (i.e. whether RBS or RCV was given greater weighting in the loss function), with the top-ranked scenarios in each case involving considerably different management measures. The methods presented can be applied anywhere using locally or strategically relevant indicators to help identify spatial fisheries management measures that minimize ecological and socio-economic trade-offs.