The Interpretation of the United Nations Convention on the Law of the Sea in the Chagos Marine Protected Area Arbitration. The Influence of the Land Sovereignty Dispute

This chapter aims at answering the question of the contribution of the Chagos Marine Protected Area Arbitration to the interpretation of the United Nations Convention on the Law of the Sea (UNCLOS). In applying to an Arbitral Tribunal convened pursuant to Part XV UNCLOS in 2011, Mauritius alleged that the United Kingdom was not entitled to unilaterally declare the Marine Protected Area in the Chagos Islands and that, in any event, the Area was incompatible with the UNCLOS. It is here argued that the precedential value of the Award for UNCLOS interpretation purposes is undermined by ambiguities that are due to the relevance of the land sovereignty dispute over the Chagos Archipelago. In particular, when Mauritius was still a colony of the United Kingdom, the Chagos Islands were detached from Mauritius to form the British Indian Ocean Territory (BIOT): for the last 40 years Mauritius has claimed sovereignty over the Archipelago. The chapter illustrates that, in the Award, the more the land sovereignty dispute has a bearing on the issue at stake, the more the interpretation of the UNCLOS turns out to be ambivalent. The ambiguities in the interpretation of the UNCLOS weaken the value of the Chagos Marine Protected Area Arbitration also with respect to the very existence of the Marine Protected Area and the land sovereignty dispute itself.