Dispute Concerning the Delimitation of the Maritime Boundary Between Bangladesh and Myanmar in the Bay of Bengal

• Jurisdiction: Derecho Internacional
• Judge: Nelson,Kateka,Ndiaye,Chandrasekhara Rao,Paik,Marotta Rangel,Treves,Bouguetaia,Jesus,Türk,Pawlak,Oxman,Akl,Gao,Yankov,Lucky,Wolfrum,Golitsyn,Hoffmann,Cot,Yanai,Mensah
• Date: 14 March 2012
• Court: International Tribunal for the Law of the Sea

International Tribunal for the Law of the Sea

(Jesus, President;Trk, Vice-President;Marotta Rangel, Yankov, Nelson, Chandrasekhara Rao, Akl, Wolfrum, Treves, Ndiaye, Cot, Lucky, Pawlak, Yanai, Kateka, Hoffmann, Gao, Bouguetaia, Golitsyn, Paik, Judges;Mensah, Oxman, Judges ad hoc)

Dispute Concerning the Delimitation of the Maritime Boundary Between Bangladesh and Myanmar in the Bay of Bengal1

(Bangladesh/Myanmar)

Sea Maritime boundary delimitation Single maritime boundary Territorial sea United Nations Convention on the Law of the Sea, 1982 (UNCLOS) Article 15 Equidistance/special circumstances Effect of islands in delimitation of territorial sea EEZ Continental shelf Continental shelf beyond 200 nautical miles UNCLOS Articles 74 and 83 Three-stage approach Equidistance/relevant circumstances Proportionality Relevant coasts Geographical context Bay of Bengal Coastal configuration Concavity of coast Cut-off effect Angle-bisector method Whether geographical configuration of Bay of Bengal warranting use of angle-bisector method Effect of islands on delimitation of EEZ and continental shelf UNCLOS Article 76 Whether ITLOS having to await delineation of outer limits of continental shelf by Commission on the Limits of the Continental Shelf before delimiting continental shelf beyond 200 nautical miles Grey area issue Whether UNCLOS allowing grey areas

International tribunals International Tribunal for the Law of the Sea United Nations Convention on the Law of the Sea, 1982 (UNCLOS) Jurisdiction Special agreement Unilateral application Maritime boundary delimitation Whether ITLOS having jurisdiction to delimit continental shelf beyond 200 nautical miles

Treaties Binding international agreements Whether 1974 Agreed Minutes binding international agreement on delimitation of territorial sea Full powers Registration of treaties Whether legal nature and content of instrument determining whether binding treaty Whether de facto or tacit agreement existing on territorial sea boundary Whether Myanmar estopped from claiming 1974 Agreed Minutes constituting a binding agreement

Summary:2The facts:On 8 October 2009, Bangladesh instituted proceedings against Myanmar under Annex VII of the United Nations Convention on the Law of the Sea, 1982 (UNCLOS) concerning the full and satisfactory delimitation of the maritime boundaries of the territorial sea, exclusive economic zone (EEZ) and continental shelf between Bangladesh and Myanmar in the Bay of Bengal. On 4 November and 12 December 2009 respectively, Myanmar and Bangladesh made declarations under UNCLOS Article 287 accepting the jurisdiction of the International Tribunal for the Law of the Sea (the Tribunal). On that basis, on 14 December 2009 the Tribunal received a letter from Bangladesh, requesting the Tribunal to exercise its jurisdiction over the dispute.

The Parties had held negotiations between 1974 and 1986, and 2008 and 2010. On 23 November 1974, the heads of the Parties' delegations signed the Agreed Minutes between the Bangladesh Delegation and the Burmese Delegation regarding the Delimitation of the Maritime Boundary between the Two Countries (the 1974 Agreed Minutes). On 1 April 2008 they signed the Agreed Minutes of the meeting held between the Bangladesh Delegation and the Myanmar Delegation regarding the delimitation of the Maritime Boundaries between the two countries (the 2008 Agreed Minutes).

Before the Tribunal, Bangladesh argued that the territorial sea boundary had been fixed in the 1974 Agreed Minutes and confirmed in the 2008 Agreed Minutes. It maintained that the 1974 Agreed Minutes constituted a valid international agreement in force between the Parties. Myanmar rejected Bangladesh's contention, arguing that the 1974 Agreed Minutes were merely a conditional agreement reached by negotiators, which had been neither signed nor ratified in accordance with the constitutional provisions in either country. The Parties also disagreed on whether the 1974 Agreed Minutes were comparable to the 1949 Procs-Verbal at issue in the Black SeaINTL cases, which the International Court of Justice had held constituted a binding agreement between Romania and the Union of Soviet Socialist Republics.3

Furthermore, Myanmar argued that the members of its delegation who signed the 1974 Agreed Minutes lacked the power to commit Myanmar to a legally binding treaty, a contention rejected by Bangladesh. Bangladesh also argued that the conduct of the Parties after 1974 showed the existence of a tacit or de facto agreement as to the territorial sea boundary; Myanmar contended that no such tacit or de facto agreement existed, and that it never acquiesced to the delimitation of the territorial sea. Bangladesh also invoked

the doctrine of estoppel, arguing that Myanmar was estopped from claiming that the 1974 Agreed Minutes were anything other than a binding treaty; Myanmar rejected this contention, and argued that Bangladesh had not relied on any conduct of Myanmar to its own detriment, and that the requirements of estoppel were therefore not met

St Martin's Island, which was at issue in the delimitation of the territorial sea, was located immediately off the coast of Myanmar and 6.5 nautical miles (nm) from the land boundary terminus, but was under Bangladesh's sovereignty. Myanmar argued that St Martin's Island constituted a special circumstance within the meaning of UNCLOS Article 15 by virtue of being on the wrong side of the delimitation line constructed between the mainland coasts, and should therefore not be given full effect in delimiting the territorial sea. Bangladesh argued that St Martin's Island should be given full effect since it was an integral part of coastal geography.

In the delimitation of the single maritime boundary beyond 12 nm, Bangladesh argued that the Tribunal should use the angle-bisector method, since the concavity of the Bay of Bengal made an equidistance line boundary inequitable. Myanmar argued that this delimitation should be effected using the equidistance/relevant circumstances method, as developed in international case law. Since its main claim was of an angle-bisector line, Bangladesh did not identify any basepoint for the construction of a provisional equidistance line.

Bangladesh argued that the concavity of the coast, the position of St Martin's Island and the Bay of Bengal depositional system were relevant circumstances to consider in adjusting the provisional equidistance line. By contrast, Myanmar argued that no relevant circumstances existed that would warrant the adjustment of the equidistance line.

Myanmar argued that the Tribunal had no jurisdiction to delimit the continental shelf beyond 200 nm, since the Commission on the Limits of the Continental Shelf (CLCS) had not yet established the outer limits of the continental shelf beyond 200 nm. Bangladesh argued that the Tribunal was empowered under UNCLOS to delimit the continental shelf in its entirety, both within and beyond 200 nm, and that the CLCS and the Tribunal had complementary, not conflicting, roles. The Parties agreed that the methodology was the same for the delimitation of the continental shelf both within and beyond 200 nm. In relation to the grey area issue, Bangladesh argued that nothing in UNCLOS clearly stated that a State's entitlement to an EEZ would trump a neighbouring State's entitlement over its continental shelf beyond 200 nm. By contrast, Myanmar contended that to create a grey area where its own sovereign rights within 200 nm would be curtailed by Bangladesh's entitlement over a continental shelf beyond 200 nm would be contrary to UNCLOS.

Held:(1) (unanimously) The Tribunal had jurisdiction to delimit the territorial sea, the EEZ and the continental shelf within 200 nm (para. 506).

(2) (By twenty-one votes to one, Judge Ndiaye dissenting) The Tribunal had jurisdiction to delimit the continental shelf beyond 200 nm.

(a) UNCLOS Article 76, which defined the continental shelf, did not differentiate between the continental shelf within and beyond 200 nm, and thus embodied the concept of the single continental shelf. In addition, UNCLOS Article 83 on continental shelf delimitation did not distinguish between the delimitation of the continental shelf within and beyond 200 nm, but provided for the use of one rule for the delimitation of the shelf in its entirety (para. 361).

(b) The delimitation beyond 200 nm effected by the Tribunal could not prejudice either the rights of third parties, pursuant to the res judicata principle, or the rights of the international community with respect to the area, since the boundary would terminate at the outer limit of the continental shelf beyond 200 nm as delineated by the CLCS. The fact that the CLCS had not yet delineated the outer limits of the continental shelf did not limit the Tribunal's jurisdiction with respect to the delimitation of the continental shelf beyond 200 nm. In the UNCLOS institutional framework, the functions of the Tribunal and of the CLCS were complementary (paras. 36794).

(c) The outer limit of the continental margin was an essential element in the determination of a coastal State's entitlement to a continental shelf beyond 200 nm. The notions of continental margin and of natural prolongation were closely inter-related, and identified the extent of the area over which the State had sovereign rights under UNCLOS Part VI. Natural prolongation was not an independent criterion which a State had to satisfy in order to be entitled to a continental shelf beyond 200 nm. The Tribunal would have had to refrain from delimiting the continental shelf beyond 200 nm had the scientific evidence as to the existence of a continental margin beyond 200 nm been uncertain. It had, however, been uncontested (paras. 42838 and 4426).

(3) (By twenty votes to two, Judges Lucky and Bouguetaia dissenting) There was no agreement between the Parties within the meaning of UNCLOS Article 15 concerning the delimitation of the territorial sea.

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