Maritime Zones

Maritime Zones areas of ocean or sea over which sovereign states and international authority claim their authority. These zones are determined following the provisions of international law and domestic law. These zones are divided into internal waters, the territorial sea, the contiguous zone, the exclusive economic zone (EEZ), the continental shelf, and the high seas. All coastal states have sovereign rights over the territorial sea. Most commonly, this area extends to a distance of 22.2 km/12 nautical miles (nm) from the baseline. The contiguous zone extends to 24 nm, where coastal state sovereign rights enforce their domestic customs, fiscal, immigration and sanitary laws. In the EEZ, states can claim fishing rights and the rights to explore and exploit natural resources up to 200 nm. Continental shelf (CS) ‘comprises the seabed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin or a distance of 200 nautical miles from the baselines.’ However, in the case of natural prolongation beyond 200 nm from the margin, the CS can extend to 350 nm. Finally, the high seas are a maritime zone where every coastal and landlocked state can exercise some limited rights, which include (a) freedom of navigation; (b) freedom of over flight; (c) freedom to lay submarine cables and pipelines, (d) freedom to construct artificial islands and other installations permitted under international law, (e) freedom of fishing, (f) freedom of scientific research.

In Bangladesh, the maritime zones are determined and regulated in light of national and international law. Bangladesh enacted the Territorial Waters and Maritime Zones Act 1974 even before the conclusion of the UN Convention on the Law of the Sea 1982 (UNCLOS), the principal international law treaty relating to the law of the sea. The Territorial Waters and Maritime Zones Act 1974 delineates different maritime zones recognised under international law. It provides for the provisions to specify the limits of each zone by notifications in the Official Gazette. The sea zones so prescribed conform with the UNCLOS. Bangladesh is a signatory to this convention.

Bangladesh follows the limit of 12 nm and 200 nm in the territorial sea and the EEZ, respectively. Bangladesh is also entitled to claim continental shelf beyond 200 nm after getting a favourable verdict against Myanmar in a landmark case relating to delimiting maritime boundaries before the International Tribunal for the Law of the Sea (ITLOS) on 14 March 2012. The verdict also established Bangladesh sovereignty over St Martin's Island by rejecting any claim Myanmar claims on the island.

The coast of Bangladesh is curved, indented and unstable, and the coastal bay has been shoaling up owing to the deposit of a colossal amount of silt, mud and particles carried by the mighty rivers Padma/Ganges and Brahmaputra/Jamuna and Meghna and their distributaries to the Bay of Bengal. The result of sediment deposits, monsoon rains, cyclonic storms and tidal surges is that the Ganges-Brahmaputra delta has no stable water line landward or seaward. The continual process of alluvion and sedimentation forms mudbanks, and the coastal water area is too shallow to be navigable except by small boats. The channels through the mudbanks are also constantly changing and require soundings by a physical survey, preferably by a joint survey of the littoral states of the area.

Due to this phenomenon, Bangladesh has prescribed a 10-fathom (60 feet) depth line to delineate baselines to measure territorial sea, contiguous zone, EEZ and the continental shelf. However, since the coastal bay is constantly changing, the baseline delineated even by depth criterion cannot be stable. Therefore, it needs to be surveyed from time to time and measures taken accordingly. This gives impetus to the maritime dispute between Bangladesh and India. On 7 July 2014, The Permanent Court of Arbitration finally resolved the dispute at the Hague, the Netherlands. The landmark verdict awarded Bangladesh against India an area of 19,467 sq km, among 25,602 sq km of the disputed maritime boundary in the Bay of Bengal. However, the verdict gives India sovereignty over the south talpatti island (known as New Moore Island, which was emerged and later diluviated in 2010) in the estuary of the Haribhanga (which borders Bangladesh and India) and Raimangal rivers. [M Habibur Rahman]