LAUSR

Abstract Marine ecosystems and the services they provide contribute greatly to human well-being but are becoming degraded in many areas around the world. The expansion of Marine Protected Areas (MPAs) has been advanced as a potential solution to this problem but their economic feasibility has hardly been studied. We conduct an economic assessment of the costs and benefits of six scenarios for the global expansion of MPAs. The analysis is conducted at a high spatial resolution, allowing the estimated costs and benefits to reflect the ecological and economic characteristics and context of each MPA and marine ecosystem. The results show that the global benefits of expanding MPAs exceed their costs by a factor 1.4–2.7 depending on the location and extent of MPA expansion. Targeting protection towards pristine areas with high biodiversity yields higher net returns than focusing on areas with low biodiversity or areas that have experienced high human impact.