Résumé
This chapter is part of a critical debate on the concept of ecosystem service. Since the Millennium Ecosystem Assessment, ecosystem services are seen as the key component of the relationship between nature (ecosystems) and human beings (sociosystems). We assume that this perspective is partly wrong. Ecosystems services are not always provided in a sustainable way. In order to bridge nature and human beings and to reach comprehensive coviability, a feedback loop is required between ecosystem and sociosystem services. The first part is dedicated to a critical presentation of ecosystem services definitions and their input to the viability of human societies. The second part focuses on the identification and the classification of ecosystem services attached to the reef environment of the Reunion Island. The third part focuses on the concept of sociosystem services whose four main types are: the ‘sanctuary of habitats’ service, the ecological engineering service, the service of ‘reduction of the anthropogenic pressure on ecosystems’, and the reduction of pollution service.