Considering the Costs of Enforcement: Improving Marine Spatial Planning

presentationGrowing industrial and consumer demands are negatively affecting fish stocks, which are extracted above sustainable levels. Successful conservation of marine resources through restricted-use zoning systems such as marine reserves and territorial user rights schemes relies on support from marine stakeholders – particularly coastal fishing communities. Restricted use zoning will result in management costs to stakeholders but also delivers benefits. To increase support for management decisions, these costs and benefits need to be taken into account when designing optimal marine management.\ud \ud \ud \ud We developed a linear spatial optimisation model to identify zoning solutions which maximize fishers’ revenue, while meeting conservation targets for two invertebrate and three reef fish species in Chile. The model maximises revenue by allocating the study area to different management zones: no-take, territorial user rights for fishing (TURFs), or open access. Enforcing no-take and TURF areas will be costly, but will result in higher species abundance by preventing poaching and overfishing. We analyse scenarios to determine the impact of enforcement on revenue.\ud \ud \ud \ud Results demonstrated net benefits from enforcement: revenue under scenarios with enforcement was approximately 50% higher than under scenarios without it, and enforced-TURF areas were preferentially selected over other zones. High enforcement costs may be a disincentive to fishers to manage marine areas. Our analysis, however, demonstrates that the often hidden benefits of enforcement far exceed the visible costs. These findings highlight the importance of accounting for both the benefits and costs of management in marine conservation; particularly as they relate to marine stakeholders