The Law of the Sea comprises a complex set of rules and principles that govern the use of oceans and seas. These rules are essential for ensuring the sustainable use of marine resources, maintaining peace and security at sea, and protecting marine biodiversity.
The sea covers more than 70% of the Earth’s surface. The oceans have become vital spaces for trade, fishing, and shipping. However, this vastness presents challenges in terms of maritime safety and environmental protection.
The United Nations Convention on the Law of the Sea (UNCLOS), adopted in 1982 in Montego Bay, Jamaica, is the fundamental treaty that governs the use of the oceans and seas. It defines the rights and responsibilities of states with regard to navigation, fishing, the exploration of marine resources, and the protection of the marine environment. UNCLOS divides the oceans into several zones, each of which is subject to a specific legal regime: the territorial sea, the exclusive economic zone (EEZ), the high seas, and the continental shelf.
The United Nations Convention on the Law of the Sea (UNCLOS) entered into force on 16 November 1994, and has since been ratified by 170 parties. It plays a decisive role in managing marine resources and resolving conflicts between coastal states. For instance, it allows states to claim an Exclusive Economic Zone (EEZ) extending up to 200 nautical miles from their coasts, thereby granting them exclusive rights to exploit the area’s natural resources.
Treaties relating to fisheries
The sustainable management of fisheries resources is a key issue in the Law of the Sea. Several international treaties aim to regulate fishing and protect marine species.
The importance of these rules is illustrated by fisheries management. The Convention on the Law of the Sea requires states to cooperate in conserving and sustainably using straddling and migratory fish stocks. The 1995 Fish Stocks Agreement, for example, aims to prevent overfishing by establishing international management measures for migratory species.
The International Convention for the Conservation of Atlantic Tunas (ICCAT), which came into force in 1969, seeks to ensure the sustainable management of tuna stocks in the Atlantic Ocean. It imposes fishing quotas and conservation measures to protect species such as bluefin tuna that are under threat.
The Port State Measures Agreement (PSMA) is the first international agreement to specifically target illegal, unreported and unregulated (IUU) fishing. Its main objective is to prevent and deter IUU fishing by ensuring that vessels involved in this activity are not permitted to dock at ports and offload their catch. This reduces the likelihood of catches from IUU fishing ending up on world markets. The PSMA also contributes to the long-term conservation and sustainable use of living marine resources and marine ecosystems. Morocco and Angola joined the agreement in 2022, strengthening the fight against illegal fishing.
Treaties on hunting and the protection of marine biodiversity
A number of treaties have been drawn up in response to overfishing and the threat it poses to biodiversity and the marine environment. The International Whaling Commission (IWC) is an intergovernmental organisation that regulates whaling. Established in 1946 after the Second World War, the IWC’s mission is to regulate whaling and conserve cetaceans. Its legal framework is provided by the International Convention for the Regulation of Whaling. In 1982, the IWC introduced a moratorium on commercial whaling, which is now prohibited worldwide and remains in force. However, populations such as the Inuit and Nunavut, who rely on this cetacean for food, are exempt.
Shark protection is also a major issue in the Law of the Sea. At the ICCAT annual meeting in Cyprus in 2024, China and Japan blocked an international effort to strengthen ICCAT’s ban on shark finning, despite scientific evidence and arguments from environmentalists. When sharks are caught, their fins are cut off while they are still alive, causing them to drown slowly and painfully. The United States, the United Kingdom, the European Union and other countries have all expressed their support for the fight to definitively ban finning.
There are also environmental management and protection treaties. The Convention on Biological Diversity (BBNJ), which was adopted in June 2023, aims to protect marine biodiversity in areas beyond national jurisdiction. It establishes a framework for creating marine protected areas and sharing benefits linked to marine genetic resources.
Specific rights of passage
Certain straits and maritime passages are subject to specific rights of passage, which are governed by international treaties. The Montreux Convention, signed in 1936, regulates the free movement of ships through the Turkish Straits (the Dardanelles and the Bosphorus) and the Black Sea. It is binding on several states, including Turkey, Russia, and Ukraine. The convention stipulates that passage and navigation in the straits ‘shall be regulated in such a manner as to safeguard the security of Turkey, the Black Sea, and the littoral states’. Turkey invoked this convention during the Second World War. By closing the straits to warships, Turkey prevented the Soviet Navy from participating in the fighting in the Mediterranean.
Another notable example is the 2015 agreement between the United States and Russia regarding the Bering Strait. The agreement permits residents of regions bordering the strait to travel to the neighbouring country without a visa, thereby facilitating cultural and economic exchanges. According to the Washington Post, residents of Alaska and the Russian Chukchi Peninsula can visit each other’s countries without a visa for up to ninety days, provided they receive an invitation from a local resident.
Treaties on safety and rescue at sea
Safety at sea is a priority for states and international organisations. Several treaties aim to ensure the safety of ships and people at sea. Adopted in 1979, the SAR Convention (also known as the International Convention on Maritime Search and Rescue) aims to establish an international plan to ensure that people in distress at sea are rescued by a search and rescue organisation. This applies no matter where the accident occurs.
The International Convention for the Safety of Life at Sea (SOLAS), first adopted in 1914 following the sinking of the Titanic in 1912, is an international treaty. Since then, it has undergone several amendments and adaptations. The SOLAS Convention sets out minimum safety standards for ships, covering everything from construction to operation and evacuation procedures. Following the sinking of the Costa Concordia in 2012, amendments were made to SOLAS as a result of the subsequent inquiry to enhance safety.
Treaties against pollution at sea
The International Convention for the Prevention of Pollution from Ships (also known as the MARPOL Convention) was signed at the IMO in 1973. It is one of the world’s most important conventions concerning the prevention of marine pollution, whether accidental or caused by operations. Some of its main rules aim to minimise pollution from ships.
The 1969 Convention on Intervention on the High Seas in Cases of Accidents Causing or Likely to Cause Oil Pollution allows coastal states to take the necessary measures to prevent, reduce, or eliminate dangers related to oil pollution. The Convention also applies in the event of a threat of pollution. In 1979, the Convention on the Physical Protection of Nuclear Material (CPPNM) was adopted. This establishes a strict legal framework to ensure that the transport of nuclear materials is protected against criminalisation and unlawful acts.
