The Chagos Marine Protected Area, located in the central Indian Ocean in the British Indian Ocean Territory of the United Kingdom, is one of the world's largest officially designated marine protected areas, and one of the largest protected areas of any type (land or sea) on Earth. It was established by the British government on 1 April 2010 as a massive, contiguous, marine reserve, it encompasses 640,000 square kilometres (250,000 sq mi) of ocean waters, including roughly 70 small islands and seven atolls of the Chagos Archipelago.
The establishment of the protected area was immediately controversial, as the Chagossian people were forcibly expelled from the archipelago, including the outlying islands, because the United States wanted a military base on Diego Garcia; their expulsion has been described as ethnic cleansing.[1][2] In a cable leaked by WikiLeaks, a US State Department official commented based on talks with British ministers and officials that establishing the reserve to restrict fishing would be the "most effective long-term way to prevent any of the Chagos Islands' former inhabitants or their descendants from resettling."[3] The same cable explained that the protection would permit environmental damage if caused by military use: "the terms of reference for the establishment of a marine park would clearly state that the BIOT, including Diego Garcia, was reserved for military uses. ... the establishment of a marine reserve had the potential to be a 'win-win situation in terms of establishing situational awareness' of the BIOT... [the government] sought 'no constraints on military operations' as a result of the establishment of a marine park." An exemption in the MPA allows people from the US base on Diego Garcia to continue fishing. In 2010, more than 28 tonnes of fish was caught for use by personnel on the base.[4][5][6]
On 18 March 2015, the Permanent Court of Arbitration unanimously held that the establishment of the marine protected area (MPA) was illegal under the United Nations Convention on the Law of the Sea, as Mauritius had legally binding rights to fish in the waters surrounding the Chagos Archipelago, to an eventual return of the Chagos Archipelago, and to the preservation of any minerals or oil discovered in or near the Chagos Archipelago prior to its return.[7][8] The decision of the court is final and binding.[9] The MPA is now under negotiation between the UK government and government of Mauritius.[10]
The CMPA is administered with assistance from the Chagos Trust, funded by donations and the British Government.[11] Tourist visitors are generally not permitted, although as of 2016 private yachts sailing across the Indian Ocean may apply for mooring permits outside the strict nature reserve areas.[12]