Social, institutional, and knowledge mechanisms mediate diverse ecosystem service benefits from coral reefs.

Ecosystem services are supplied by nature but, by definition, are received by people. Ecosystem service assessments, intended to influence the decisions people make regarding their interactions with nature, need to understand how people benefit from different ecosystem services. A critical question is therefore, What determines the distribution of ecosystem service benefits between different sections of society? Here, we use an entitlements approach to examine how people perceive ecosystem service benefits across 28 coral reef fishing communities in four countries. In doing so, we quantitatively show that bundles of benefits are mediated by key access mechanisms (e.g., rights-based, economic, knowledge, social, and institutional). We find that specific access mechanisms influence which ecosystem services people prioritize. Social, institutional, and knowledge mechanisms are associated with the largest number and diversity of benefits. However, local context strongly determines whether specific access mechanisms enable or constrain benefits. Local ecological knowledge enabled people to prioritize a habitat benefit in Kenya, but constrained people from prioritizing the same benefit in Madagascar. Ecosystem service assessments, and their resultant policies, need to include the broad suite of access mechanisms that enable different people to benefit from a supply of ecosystem services.