Comparing voluntary and government-mandated management measures for meeting sustainable fishing targets.

Management of natural resources and environmental systems has often involved top-down approaches in which government agencies set and enforce regulations on extractive activities. More recently, market-driven approaches were introduced to incentivise producers to voluntarily engage in practices that align with management objectives and support regulations. For the first time, we compare government and voluntary approaches within fisheries management systems and quantify their relative influences on the sustainability status of fish populations. Voluntary measures include eco-certification against the Marine Stewardship Council's (MSC) Fisheries Standard and Fishery Improvement Projects (FIP). Government-mandated measures are implemented for individual populations, or else at national and international levels. Using a hierarchical time series analysis, we treated each of these measures as independent interventions potentially affecting trends in fishing pressure and biomass of nearly 300 populations. Supporting earlier findings, we confirmed a strong effect of government rebuilding plans in sharply reducing fishing pressure and allowing population biomass to recover. Other government-mandated measures further contributed to reducing fishing pressure. While simultaneously accounting for government measures, we found that biomass increases were associated with stronger incentives generated by voluntary measures. This influence was attributed to the opening of conditions of certification or suspension of certification for MSC fisheries, while no clear influence was attributed to FIPs. MSC certification was rarely observed in the absence of strong government-mandated measures, however, suggesting that sustainability-related incentives associated with voluntary measures can promote more desirable environmental outcomes for target stocks if used in parallel with more conventional approaches to management of natural resources.