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Text updated and expanded to reflect research into maritime delimitation and recent developments in the law of the sea; updated citations,references, and links to digital materials.

Updated on 22 November 2019. The previous version of this content can be found here.
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date: 04 July 2020

Summary and Keywords

The International Law of the Sea, or simply Law of the Sea, is a body of legal norms that regulate the use of the seas and delineate the powers and jurisdiction of States over various parts of the seas. The evolution of the Law of the Sea can be divided into three different eras: the 17th-century great debate over open versus closed seas, era of codification, and era of institutionalization. The debate between early scholars over the issue of whether the sea was open to all and subject to the freedom of the seas (mare liberum or open seas) or whether the seas could be subject to sovereignty by States (mare clausum or closed seas) became the generally accepted basis for contemporary law of the sea. The era of codification saw the convening of three United Nations Conferences on the Law of the Sea—UNCLOS I, UNCLOS II, and UNCLOS III. The Law of the Sea Convention (LOSC), adopted in 1982, initiated an era of the institutionalization of the law of the sea. From early in the 21st century, the international community appears to be leaning toward closed seas, but there are also indications that cooperative arrangements among parties on the law of the sea will be more prevalent. An example of such initiative is the 1995 Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks.

Keywords: Law of the Sea, international law, codification, institutionalization, freedom of the seas, open seas, mare clausum, closed seas, United Nations Conference on the Law of the Sea, Law of the Sea Convention

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