Collective choices for the conservation of living marine resources: an economic analysis applied to the cases of coral fisheries and international exploitation of large cetaceans.

Summary The general framework of this thesis is the study of the problems of collective choice for the conservation of living marine resources. The question is raised about the necessary adaptations of the classical economic interpretations and analyses, due to the recent evolution of the definition of these problems. The thesis is based on the comparative analysis of an international case - the exploitation of large cetaceans, and a local case - the exploitation of coral reefs, approached in an evolutionary way to illustrate the studied evolutions. It is developed in three parts. The first part presents the way in which the natural resource economy approaches collective choices for the protection of life. The analysis shows the central role played by the notion of authority, and brings to light an essential question: that of the nature and origin of the control that can be exercised by agents over elements of the marine ecosystem. After reviewing the standard approach to the problems of fisheries control, the second part studies the consequences for this approach of the recent evolutions in the definition of conservation problems towards a greater consideration of the natural and human context in which fisheries operate, both at the national and international levels. It shows that while the tools of classical bioeconomics allow us to partially understand these changes, they do not allow us to grasp the nature of the process leading to the elaboration of mechanisms for controlling access to marine ecosystems. The third part explores this procedural dimension of collective decision problems. Based on the tools developed for the study of sequential choice problems in other fields, the analysis shows the interest of a dynamic approach of the decision, conceived as a sequence of choices building, in time, the evolution trajectories of the exploited systems. An analysis of the collective dimension of conservation decisions is also developed, based on a comparative study of the emergence of control mechanisms in the local and international situations considered.