Pacific island societies are usually described from a simplistic angle as homogeneous and culturally i n harmony with their natural environment. They would have an innate « know-how » to sustainably manage their resources which implies a conception o f governance essentially based on a simple transfer of decentralized competencies. However, pa cific island societies are heterogenous, dynamic and contemporaneous. Heterogeneous because composed of social groups in perpetual competition. Dynamic and contemporaneous because, far from remaining closed from the outside, they show a real ability for taking advantage of any opportunity whi ch will enable some groups of people to weigh on the social game, and development projects may often be hijacked. To face this complexity, the process of integrated management must rely on a less naïve and more pragmatic conception of « governance », amongst which local actors should play a more « negociated » role. Within the CRISP 1 Programme, the GERSA 2 project will have a transversal approach in compon ent 1 aiming at implementing Marine Protected Areas. The in-depth analysis of local soc ieties from the cultural geography and socio- economy points of view will totally be integrated i n the implementation of more usual tools, and should secure the effective involvement of local ac tors in the process of management, including in its technical aspects.