Exclusive economic zone

The EEZ regime is defined primarily in Part V of UNCLOS (Articles 55–75). Within the EEZ, the coastal state has sovereign rights for the purpose of exploring and exploiting, conserving and managing natural resources, whether living or non-living, of the waters superjacent to the seabed and of the seabed and its subsoil. It also has jurisdiction over the establishment and use of artificial islands, installations and structures, marine scientific research, and the protection and preservation of the marine environment. Other states retain the freedoms of navigation and overflight and the laying of submarine cables and pipelines, provided they have due regard to the coastal state's rights and duties. The EEZ is not part of the territorial sea; it is a sui generis zone, distinct from both the territorial sea and the high seas.

Delimitation of EEZs between states with opposite or adjacent coasts is to be effected by agreement on the basis of international law, as stated in Article 74 of UNCLOS, in order to achieve an equitable solution. This has led to numerous bilateral treaties and international adjudications, such as the 2007 Guyana–Suriname arbitration and the 2012 Bangladesh–Myanmar case before the International Tribunal for the Law of the Sea. Unresolved disputes, such as those in the South China Sea, remain contentious. The 2016 Permanent Court of Arbitration ruling in the Philippines v. China case clarified that certain features are rocks that cannot generate an EEZ, underscoring the legal distinction between islands and rocks under Article 121.

Coastal states have the exclusive right to regulate fishing within their EEZs, and they are obligated to ensure that living resources are not endangered by over-exploitation, as per Article 61. This has led to the establishment of total allowable catches and national quotas. Many states also use their EEZs for offshore oil and gas extraction, which accounts for a significant share of global hydrocarbon production. The EEZ concept has also been instrumental in the development of marine protected areas, such as the Papahānaumokuākea Marine National Monument in the United States, which lies within the U.S. EEZ. However, illegal, unreported and unregulated fishing remains a persistent challenge, prompting initiatives like the Port State Measures Agreement.

Beyond the familiar 200-nautical-mile limit, several nuances exist. For instance, the EEZ does not include the continental shelf beyond 200 nautical miles, where the coastal state has sovereign rights over seabed resources but not over the water column. Some states, such as Brazil, have claimed a 'legal continental shelf' extending beyond 200 nautical miles, subject to the Commission on the Limits of the Continental Shelf. The concept of the EEZ was first proposed by Chile in 1947, and it was later championed by developing states during the Third UN Conference on the Law of the Sea. Also, the EEZ does not confer sovereignty over the airspace; however, states may restrict military activities in their EEZ under certain interpretations. The Arctic Ocean has seen increased EEZ claims as ice melts, with Russia and Canada asserting extended continental shelf claims. Additionally, the EEZ of France is the largest in the world, covering over 11 million square kilometers, due to its overseas territories.

Baselines

The lines from which the breadth of the territorial sea and other maritime zones are measured, usually the low-water line along the coast.

Sovereign rights

Exclusive rights of a coastal state over resources in its EEZ, falling short of full sovereignty.

Continental shelf

The seabed and subsoil extending beyond the territorial sea to the outer edge of the continental margin, over which the coastal state has rights to natural resources.