Historical Background of Maritime Laws in the Pacific

For millennia, the peoples of the Pacific Ocean navigated its vast expanses and harvested its resources under systems of customary law deeply rooted in kinship, tradition, and practical necessity. These unwritten codes governed access to fishing grounds, defined territorial sea boundaries between island communities, and regulated the use of navigation routes. For example, in Micronesia, traditional navigators passed down detailed knowledge of currents, stars, and reefs, and their authority was respected across island groups. Similarly, Polynesian societies developed sophisticated protocols for resource allocation, ensuring sustainable use of marine life. These indigenous legal orders were not static; they evolved through inter-island diplomacy and conflict resolution.

The arrival of European explorers and colonial powers in the 16th through 19th centuries radically altered the legal landscape. Spanish, Portuguese, British, French, and later German and American interests imposed formal legal frameworks derived from European maritime law and colonial decrees. Treaties of cession, often negotiated under duress or misunderstanding, transferred sovereignty over vast ocean territories. The doctrine of terra nullius (land belonging to no one) was applied to many Pacific islands, disregarding existing customary governance. Colonial administrations introduced concepts of straight baselines and territorial seas measured from low-water lines, displacing indigenous boundaries. These impositions created a patchwork of legal claims that continue to shape disputes today, with many Pacific nations still grappling with the legacy of colonial cartography and legal imposition.

The early 20th century saw the first multilateral efforts to codify maritime law, but the Pacific remained largely governed by bilateral agreements among colonial powers. The League of Nations mandates after World War I transferred control of German territories, yet no comprehensive regional maritime law emerged. It was not until the post-World War II era, with the rise of newly independent Pacific Island states, that the push for a universal legal regime gained momentum. The 1958 Geneva Conventions on the Law of the Sea, though limited in scope, laid groundwork for the later, more ambitious United Nations Convention on the Law of the Sea (UNCLOS). However, the Pacific’s unique geography—thousands of islands, vast distances, and delicate ecosystems—required a regime that balanced coastal state sovereignty with the interests of maritime navigation and global trade.

The United Nations Convention on the Law of the Sea

UNCLOS, adopted in 1982 after years of negotiation and entering into force in 1994, represents the most comprehensive effort to establish a global legal framework for the world’s oceans. Its impact on the Pacific Ocean has been profound. For the first time, all states—whether large maritime powers or small island developing states—agreed to a common set of rules governing territorial seas, contiguous zones, exclusive economic zones (EEZs), the continental shelf, high seas, and the deep seabed. The treaty also created dispute resolution mechanisms through the International Tribunal for the Law of the Sea and arbitration bodies.

For Pacific Island nations, UNCLOS provided the legal basis to claim vast EEZs extending 200 nautical miles from their coastlines. This allowed them to exert sovereign rights over rich tuna fisheries, mineral resources, and potential hydrocarbons. Nations like Kiribati, the Solomon Islands, and Papua New Guinea now manage huge ocean spaces that dwarf their land territories. However, the treaty also placed responsibilities on coastal states: to conserve and manage living resources, protect the marine environment, and ensure that foreign vessels exercise their rights of passage peacefully. The United Nations Division for Ocean Affairs and the Law of the Sea provides guidance on implementing these obligations, and Pacific states regularly submit reports and participate in UN consultations to refine their policies (UN DOALOS).

One of the most significant features of UNCLOS for the Pacific is Part V on the exclusive economic zone and Part VI on the continental shelf. These provisions allowed many states to claim expanded continental shelves beyond the 200-nautical-mile limit, particularly relevant for nations with large submerged landmasses like Fiji and Tonga. The Commission on the Limits of the Continental Shelf (CLCS) has received numerous submissions from Pacific states, and the process of delimiting these boundaries continues to be a major legal and technical undertaking. However, the treaty is not without critics. Some argue that its framework favors established maritime powers, that it fails to adequately address the impacts of climate change on baselines, and that it leaves loopholes for overfishing and pollution on the high seas.

Key Maritime Rights and Zones

Territorial Waters

Under UNCLOS Article 3, coastal states have full sovereignty over a belt of sea extending up to 12 nautical miles from their baselines. This includes the airspace, seabed, and subsoil. In the Pacific, this means that islands and archipelagic states can regulate all activities within these waters, including foreign shipping, fishing, and scientific research. Many Pacific nations enforce strict entry requirements for foreign vessels, requiring prior authorization for warships and research ships. The right of innocent passage, however, remains for merchant vessels, provided they do not threaten the peace or security of the coastal state. Disputes over innocent passage have arisen, particularly in relation to large fishing fleets or naval exercises near sensitive marine protected areas.

Exclusive Economic Zones

Perhaps the most impactful legal creation for Pacific Island states is the exclusive economic zone. Extending 200 nautical miles from the baseline, the EEZ grants coastal states sovereign rights over all natural resources—fish, oil, gas, and minerals—both in the water column and on the seabed. It also gives authority over economic activities like energy production from waves and currents. For a nation like Tuvalu, with a land area of just 26 square kilometers but an EEZ spanning around 900,000 square kilometers, these zones are economically vital. Revenue from fishing licenses, particularly for tuna, constitutes a major portion of national budgets for many Pacific Island countries. The Pacific Islands Forum Fisheries Agency (FFA) coordinates licensing and monitoring among member states to ensure sustainable management and equitable distribution of fishing opportunities (FFA).

However, the EEZ regime also creates overlapping claims and boundary disputes. The Pacific is dotted with islands and atolls that often lie within 400 nautical miles of each other, leading to complex delimitation negotiations. States like Fiji, Vanuatu, and the Solomon Islands have engaged in bilateral talks and, in some cases, submitted disputes to international arbitration. The rules in UNCLOS Articles 74 and 83 call for equitable solutions based on international law, but these negotiations can be protracted and politically sensitive. As sea levels rise, some Pacific nations are advocating for the permanent protection of their EEZ baselines, even if the physical coastline changes, to prevent the loss of maritime zones that sustain their economies.

Freedom of Navigation and the High Seas

The high seas, defined as waters beyond any national jurisdiction, are governed by the principle of freedom of navigation. All states—coastal or landlocked—enjoy the right to sail ships, fly aircraft, lay submarine cables, and conduct fishing and scientific research on the high seas, subject to certain limitations under international law. In the Pacific, the high seas cover vast areas, and this freedom is essential for global shipping and trade. The Asia-Pacific region is a major shipping corridor, with routes crossing the Pacific connecting North America, East Asia, and Oceania. However, the freedom of navigation is often contested. The US and other navies conduct freedom of navigation operations (FONOPs) to challenge what they see as excessive maritime claims by some Pacific nations, particularly regarding archipelagic sea lanes passage.

High seas fisheries in the Pacific are managed through regional fisheries management organizations, such as the Western and Central Pacific Fisheries Commission (WCPFC). While UNCLOS requires states to cooperate in the conservation of high seas living resources, illegal, unreported, and unregulated (IUU) fishing remains a persistent problem. Many Pacific states lack the naval capacity to patrol their vast waters, making them vulnerable to poaching by foreign vessels. The Agreement on Port State Measures (PSMA) has helped strengthen controls, but enforcement is challenging. Additionally, the high seas are increasingly used for scientific research on climate change, ocean acidification, and biodiversity, raising issues of marine genetic resources and benefit-sharing.

Contemporary Challenges and Disputes

Overlapping Claims and Maritime Boundaries

Despite the clarity that UNCLOS has provided, the Pacific Ocean remains home to numerous overlapping maritime claims. One of the most contentious areas is the South China Sea, which lies partially within the Pacific region. Multiple nations—China, Vietnam, the Philippines, Malaysia, Brunei, and Taiwan—claim overlapping sovereignty over islands, reefs, and the surrounding waters. While the South China Sea is a separate water body from the central Pacific, its legal disputes affect the broader understanding of maritime rights in the region. The 2016 Permanent Court of Arbitration ruling on the Philippines versus China case clarified that China's claims based on the "nine-dash line" had no legal basis under UNCLOS, yet China has not complied with the ruling, leading to ongoing tensions (PCA Press Release).

In the central and western Pacific, overlapping EEZ claims exist between states like Tonga and Fiji, and between the Solomon Islands and Vanuatu. These disputes are generally handled through bilateral negotiations, but they can stall development projects such as seabed mining. The International Seabed Authority (ISA) regulates mineral exploration beyond national jurisdictions, but overlapping claims near the edges of continental shelves complicate the process. The Pacific Islands Forum has established a Pacific Regional Maritime Boundaries Project to help member states delimit their boundaries consistently and submit claims to the CLCS.

Illegal Fishing and Resource Exploitation

Illegal, unreported, and unregulated fishing is a multi-billion dollar problem in the Pacific. Large foreign fleets, particularly from Taiwan, China, Korea, and Japan, have been implicated in IUU fishing within EEZs of Pacific Island states. These activities deplete tuna stocks, damage coral reefs, and undermine local economies that depend on sustainable fisheries. The Pacific Islands Forum Fisheries Agency and the Secretariat of the Pacific Community work together to share vessel monitoring system data and conduct joint surveillance operations. The development of the Regional Fisheries Surveillance Center in the Solomon Islands, funded by international partners, has improved real-time tracking of suspicious vessels. However, the vastness of the Pacific Ocean makes complete enforcement impossible without greater international cooperation and resources.

Beyond fisheries, seabed mining in the Pacific presents both opportunities and legal challenges. The Clarion-Clipperton Zone, a region in the eastern Pacific, contains rich polymetallic nodules. The ISA has issued exploration contracts to several countries and companies. However, environmental concerns about deep-sea mining’s impact on fragile ecosystems have led to calls for a moratorium. Pacific Island nations are divided: some see seabed mining as a path to economic development, while others, like Fiji and Papua New Guinea, are proceeding cautiously due to risks of habitat destruction and disruption of traditional livelihoods. The legal framework for seabed mining is still evolving, and the region is closely watching precedent-setting cases.

Climate Change and Maritime Boundaries

Climate change poses an existential threat to many low-lying Pacific Island nations. Rising sea levels are eroding coastlines, inundating islands, and threatening to submerge entire atolls. This has profound legal implications for maritime zones, which are measured from baselines that may shift or disappear. Under current UNCLOS, if an island becomes uninhabitable or is submerged, its maritime claims could be lost. Pacific nations, led by the Pacific Islands Forum and the Alliance of Small Island States (AOSIS), have pushed for international recognition that baselines should remain fixed, even if the physical coastline changes. The Pacific Regional Environment Programme (SPREP) has been instrumental in documenting baseline changes and advocating for legal certainty (SPREP).

In 2021, the International Law Commission began studying the issue, and several declarations have been made, such as the 2021 Pacific Islands Forum Declaration on Preserving Maritime Zones Amid Sea-Level Rise. These declarations are not yet legally binding, but they represent a significant step in customary international law. The challenge is to balance the principle of stability of maritime boundaries with the reality of a changing climate. Additionally, rising ocean temperatures and acidification affect fish migration patterns, potentially altering the distribution of tuna and other pelagic species. This could lead to new disputes over fishing rights as stocks move across maritime boundaries.

Regional Cooperation and Enforcement

Given the limitations of individual Pacific Island states in enforcing maritime laws, regional cooperation is essential. The Pacific Islands Forum (PIF), with its 18 member states, provides a political platform for discussing common maritime concerns, such as boundary delimitation, fisheries management, and environmental protection. The PIF’s 2002 Framework for a Pacific Oceanscape was updated in 2019 to integrate climate change adaptation and sustainable development goals. Under this framework, members have committed to improving maritime governance through shared databases, joint patrols, and capacity building.

The Forum Fisheries Agency (FFA), based in Honiara, Solomon Islands, coordinates the largest tuna fishery in the world. Through the Vessel Day Scheme (VDS), FFA members allocate fishing days to foreign fleets, ensuring sustainable catch limits and fair revenue distribution. The scheme relies on a central monitoring system that tracks vessels via satellite and AIS. When vessels violate rules, such as fishing without a license or entering a restricted area, the FFA can impose sanctions, including banning the vessel from all member EEZs. This collective approach gives small island states negotiating leverage they would lack individually.

Naval cooperation is also growing. The Pacific Maritime Security Program, funded by Australia, provides patrol boats to Pacific Island nations and supports joint surveillance operations. Similarly, the US Coast Guard conducts bilateral training and operations in the region. The Nautical Institute and other organizations offer training for maritime law enforcement personnel. Despite these efforts, gaps remain. Many Pacific nations have limited coast guard capacity and depend on external support, which can create dependencies and political sensitivities. Furthermore, the rise of illegal, unreported, and unregulated fishing by industrial fleets often outpaces enforcement innovation.

Conclusion

The development of maritime laws and rights in the Pacific Ocean is a story of adaptation: from ancient customary systems through colonial impositions to the modern, complex regime of UNCLOS. The framework has empowered Pacific Island states to claim and manage vast ocean spaces, providing economic opportunities and a basis for sustainable resource use. Yet challenges persist—overlapping claims, illegal fishing, seabed mining disputes, and the existential threat of climate change. Regional cooperation through bodies like the Pacific Islands Forum, the Forum Fisheries Agency, and the Secretariat of the Pacific Community has been instrumental in addressing these challenges. Moving forward, the resilience of Pacific maritime law will depend on the willingness of all stakeholders—coastal states, maritime powers, international organizations, and civil society—to refine legal instruments, invest in enforcement capacity, and uphold the principles of equity and sustainability that underpin the law of the sea. The Pacific Ocean, as a global commons and a home to diverse cultures, demands nothing less.