De-limitation of the Bangladesh-Myanmar Maritime Border



Bangladesh instituted arbitral proceedings against Myanmar under Annex VII of the UN Convention on the Law of the Sea (UNCLOS) in October 2009 in order to secure a maritime delimitation with Myanmar for its territorial sea, exclusive economic zone (EEZ) and continental shelf. Bangladesh filed the case both against India and Myanmar as it claimed that its two neighbors had unfairly cut off a significant portion of its maritime area in the Bay. It has been arguing for an equitable solution principle as a common rubric of measurement, while Myanmar and India favor the principle of equidistance for the delimitation of boundary. The principle of equidistance, which decides maritime boundaries through geometric calculations, leaves very little portion of the Bay for Bangladesh.

Eventually, both Bangladesh and Myanmar accepted the jurisdiction of the International Tribunal for the Law of the Sea (ITLOS) for resolution of the dispute. Prior to the ITLOS proceedings Bangladesh and Myanmar held maritime boundary delimitation negotiations between 1974-86 and 2008-10.

The ITLOS, in its verdict of 14 March 2012, upheld Bangladesh’s claim to a 200-nautical mile (nm) exclusive economic and territorial rights in the Bay of Bengal. The verdict also gave Bangladesh a substantial share of the outer continental shelf beyond 200 nm, which opens the way for offshore oil and exploration in the Bay. It is the first time that any international tribunal has delimited the maritime area beyond the 200 nm. Bangladesh gained a full 12nm mile territorial sea around St Martin’s Island contrary to Myanmar’s proposal that the island be given only 6nm of sea.

Delimitation of the territorial sea

Bangladesh requested the tribunal adjudge the maritime boundary of the territorial sea as a line agreed by the states in 1974 and reaffirmed in 2008 or on the basis of equidistance method as per Article 15 of the UNCLOS. Myanmar argued that this ‘so-called 1974 agreement’ was a provisional understanding reached at one stage of technical talks. By contrast Bangladesh argued that an agreement need not take the form of a full and binding treaty as Myanmar had enjoyed the benefits of the 1974 agreement, a stable maritime boundary for over 30 years. These included the right of free and unimpeded passage through Bangladesh’s territorial waters to and from the border river-Naaf dividing both countries land boundary for conducting trade and commerce. ITLOS found that the 1974 and 2008 minutes did not constitute an agreement within the meaning of UNCLOS Article 15. Myanmar argued the St. Martin’s Island was a “special circumstance” which should not be given full effect for the territorial sea delimitation since this would lead to distortion of the general configuration of the coastline of the two states. Thus, Myanmar wanted St. Martin’s Island to generate a territorial sea of just 6 nm, rather than the 12 nautical miles to which Bangladesh is entitled under Article 15 of UNCLOS. It also argued that the island could not be described as a “coastal island” because it lay in front of the coast of Myanmar, and not that of Bangladesh, to which it belongs.

Bangladesh argued that St. Martin’s Island should be given full effect because international law demanded it. In prior cases, international tribunals had awarded islands a territorial sea of less than 12 nm only when they were barren and uninhabitable. By contrast, Bangladesh stressed that St. Martin’s Island, in addition to being an important base for naval operations for the Bangladesh Navy, had an area of eight square kilometers and a permanent population of about 7,000 people. The Tribunal agreed with Bangladesh’s claims and gave full effect to St. Martin’s Island in delimiting the territorial sea. It noted that while St. Martin’s Island
lay in front of Myanmar’s mainland coast, it was located almost as close to Bangladesh’s mainland coast as to the coast of Myanmar and was situated within the 12 nm territorial sea limit from Bangladesh’s mainland coast. Bangladesh was therefore permitted a full 12 nm territorial sea around the island. On this view the delimitation line follows an equidistance line up to the point beyond which the states’ territorial seas no longer overlap. The line is almost identical as agreed in 1974. ITLOS noted that a conclusion to the contrary would result in giving more weight to the sovereign rights and jurisdiction of Myanmar in its exclusive economic zone and continental shelf than to the sovereignty of Bangladesh over its territorial sea.

The delimitation of EEZ and the continental shelf within 200nm

ITLOS was asked to draw a single delimitation line for both the EEZ and continental shelf under UNCLOS Articles 74 and 83. The applicable law for the delimitation of the single boundary for the exclusive economic zone and continental shelf within 200 nm, according to the Tribunal, is to be found in the UNCLOS, customary international law and judicial decisions. Bangladesh argued for the use of the angle bisector method in delimitation of the EEZ and continental shelf. This would permit the Bangladesh EEZ to reach its 200nm limit, and permit the prolongation of the continental shelf beyond this distance. Myanmar argued that this method too would produce an inequitable result.

Concavity of Bangladesh coastline: The land territory of Bangladesh is located at the northern limit of the Bay of Bengal in a broad and deep concavity between Myanmar in the east and India in the west. Because Bangladesh is tucked between Myanmar and India in the concavity described by the Bay of Bengal’s north coast, Myanmar’s proposed equidistance line would have converged a short distance in front of the Bangladesh coast with the equidistance line India had claimed as its maritime boundary with Bangladesh. Together, these two lines would have created a “cut-off” effect that would have deprived Bangladesh of the overwhelming majority of its maritime entitlement. The combined effect of the equidistance lines claimed by Myanmar and India was that the two lines quickly met and truncated Bangladesh’s maritime entitlement at a distance of just about 130 nautical miles from the Bangladesh coast, leaving it with a narrow wedge of maritime space. Notwithstanding Bangladesh’s substantial 421 km coastline, the equidistance lines claimed by its neighbors would have prevented it from reaching even its 200 nm limit, much less its natural prolongation in the outer continental shelf beyond 200 nm.

Myanmar, advocating equidistance, maintained that there were no relevant factors contributing to a disproportional effect. Bangladesh disagreed, citing the co

ncavity of the Bangladesh coastline, St Martin’s Island and the Bengal depositional system as three relevant circumstances. The tribunal found that the concavity of the coastline did produce a disproportional effect, cutting off the maritime projection of Bangladesh. On the status and effect to be afforded to St Martin’s Island ITLOS argued that there existed no general rule and specific circumstances were deemed vital. Because giving the island effect in EEZ and continental shelf delimitation would block the projection of the line from Myanmar’s coast, it would produce an unwarranted distortion of the line. So the island was given no effect in EEZ/continental shelf delimitation (a contrast to the territorial sea delimitation). As for the depositional system, the tribunal did not consider it to represent a special circumstance.

ITLOS adopted the three-step method used by the ICJ–according to which it first drew an equidistance line, then checked its equitableness in light of relevant circumstances, and finally assessed the outcome on the basis of the proportionality criterion. The ITLOS then selected base points on the coast of both countries to draw a provisional delimitation line. Turning to relevant circumstances, the Tribunal accepted Bangladesh’s contention that its concave coast was relevant. According to the Tribunal, it is not concavity itself that is relevant, but rather the cut-off effect that a concave coast produces. Accordingly, it decided to modify the provisional line, by drawing a geodetic line starting at an azimuth of 215° from a point on the provisional line close to the coast. Geology of the seabed is considered irrelevant in law and in practice, because the delimitation of a single maritime boundary is to “be determined on the basis of geography” and not geology or geomorphology.

Delimitation of the Continental Shelf beyond 200nm

In the case of the continental shelf beyond 200 nm, the Tribunal had to address the contention by Myanmar that it (the Tribunal) did not have jurisdiction to rule on the matter, and that even if it did, it ought not to exercise it in the present case. It was the first time that an international court or tribunal had to address the law and practice of delimiting the continental shelf beyond 200 nm. ITLOS made it clear that a court or tribunal having jurisdiction on the basis of Part XV of the UNCLOS could delimit the continental shelf beyond 200 nm even in the absence of recommendations by the Commission on the Limits of the Continental Shelf. I maintained that there were no reasons to abstain from exercising its jurisdiction.

The Tribunal therefore rejected Myanmar’s argument that it should decline jurisdiction over the issue of the delimitation in the outer continental shelf. The Tribunal also rejected Myanmar’s argument that Bangladesh had no rights in the outer continental shelf because the delimitation should stop it from ever getting there. In delimitating the outer continental shelf, the Tribunal decided that the concavity of Bangladesh’s coast continued to be relevant. Any cut-off of Bangladesh would have to be minimized. Accordingly, the Tribunal decided to extend the same 215° line it adopted within 200 nm into the area beyond 200 nm. The Tribunal did not specify the end-point of the 215° line but rather put an arrow on the end of it, saying it should continue in the same direction until it reaches the area where the interests of a third State (namely, India) are affected. Never once either in negotiations — or even before the Tribunal — did Myanmar recognize Bangladesh’s rights beyond 200nm. It insisted Bangladesh should be kept out of the area altogether. Now, as a result of the Judgment, Bangladesh will enjoy sovereign rights over a sizable portion of the outer continental shelf. The Tribunal’s decision to accept jurisdiction was a path-breaking one. In so doing, it became the first international tribunal to delimit in the outer continental shelf. The final delimitation is shown in the sketch-map no. 7, reproduced below.

The only relevant circumstance to be considered was the concavity of the coast and the drawing of the delimitation line through the so-called “grey area” at an azimuth of 215 deg until it reaches the interest of third party (namely India). ITLOS said that when by reason of the employment of a delimitation method other than the equidistance line, the extended continental shelf of a State as delimited by a boundary line is beneath the exclusive economic zone of the other; with the latter still exercising all its rights over the water column. In such situations, each state, in exercising its rights and obligations, is under an obligation to have due regard to the rights and obligations of the other. This part of the judgment thus provided valuable guidance for future cases with respect to entitlement, delimitation, and management of overlapping rights.

While delimiting the boundary of the continental shelf beyond 200nm, the tribunal defined that “natural prolongation” for the purposes of Art. 76 UNCLOS is very much the same as the continental margin, as defined in the same article. Thus, only geomorphology and not geology (which describes the composition of the subsoil, i.e. under the seabed) is relevant in determining whether there is an overlapping of entitlements including that a “significant geological discontinuity” is not relevant for determining entitlement and that the geographic origin of the sedimentary rocks is similarly irrelevant. It also implied that entitlement to the continental shelf did not depend on any procedural requirements, implicitly lending support to the opinion that submission to the Commission on the Limits of the Continental Shelf was not a necessary prerequisite for claiming a continental shelf beyond 200 nm. The Tribunal’s only requirement was to fix the outer limit.

Finally, the Tribunal evaluated the proportionality of the boundary reached in the light of the ratio between the relevant coasts of the two States and the ratio between the areas attributed to each. Taking into account ‘the coastline and its sinuosity’ the tribunal considered the states’ respective coastal lengths, disagreeing with the interpretations of both states. In the concluding “disproportionality test”, the Tribunal, after noting that mathematical precision was not required in carrying out this task, completed the delimitation exercise stating that a ratio of 1:1.42 (length of coasts) to 1:1.54 (area attributed to each) was not significantly disproportionate.

This verdict thus validated Bangladesh’s demand for equity-based demarcation as per UNCLOS 74 and 83. The implication of this verdict for Bangladesh is good. The verdict will enable the enhancement of medium and long-term energy security interests of the country. With expansion of the maritime boundary, the opportunities for the nation’s fishing industry have also been enhanced as fishing now can be carried out in the deep sea.