An exclusive economic zone, or EEZ, is an area of sea in which a coastal state has special rights to explore, use, conserve and manage natural resources. Under the United Nations Convention on the Law of the Sea, an EEZ may extend up to 200 nautical miles from the baselines used to measure the territorial sea, subject to the rights of neighbouring states and rules on overlapping claims. It is not the same as national territory: other countries generally retain freedoms such as navigation and overflight. Understanding EEZs helps explain why fisheries, offshore energy, islands and maritime boundaries can become major international issues. The key is to distinguish ownership of land, sovereignty over territorial waters and limited economic rights in a wider maritime zone.
Key takeaways
- An EEZ can extend up to 200 nautical miles from a coastal state’s baselines.
- Coastal states have sovereign rights over resources, not full sovereignty over the entire EEZ.
- Other states retain important freedoms, including navigation and overflight.
- Overlapping EEZ claims require delimitation under international law, often through negotiation.
- Fisheries, offshore energy, environmental protection and small islands all make maritime zones geopolitically important.
What is an exclusive economic zone?
An EEZ is a legal maritime zone defined by the United Nations Convention on the Law of the Sea, commonly abbreviated UNCLOS. It begins beyond the territorial sea and is adjacent to it. Within the EEZ, a coastal state has specified rights relating to natural resources in the water, seabed and subsoil, as well as certain economic activities such as producing energy from currents and winds. The state also has jurisdiction in defined matters including marine environmental protection and scientific research. These are substantial powers, but they are not identical to sovereignty over land territory.
The distinction is central to understanding ocean disputes. A country may regulate fishing in its EEZ without having the right to exclude every foreign ship from travelling through it. Likewise, another state may have freedom of navigation without gaining permission to exploit fish stocks or oil resources. Earth Site’s article about why the Strait of Malacca matters to global trade provides a useful example of why navigation routes and economic jurisdiction must be considered separately.
How far does an EEZ extend?
UNCLOS Article 57 sets the maximum breadth at 200 nautical miles measured from the baselines used to calculate the territorial sea. A nautical mile is 1,852 metres, so 200 nautical miles equal 370.4 kilometres. This is a maximum distance, not a guarantee that every coastal state has an undisputed 200-mile zone in every direction. In narrow seas, neighbouring coasts may be much closer together. Maritime boundaries must then be delimited between the states concerned.
Baselines are legally defined reference lines along or near the coast, subject to rules in the convention. The shape of the coastline, islands and agreed boundaries can affect the result. Students should not draw a simple circle around a country on a small-scale map and assume it is the official EEZ. A map showing national maritime claims may also include disputed areas. Accurate interpretation requires checking the source, legal status and date of the boundary data.
What is the difference between an EEZ and territorial waters?
The territorial sea normally extends up to 12 nautical miles from the baseline. A coastal state exercises sovereignty over this area, subject to rules such as innocent passage by foreign vessels. The EEZ lies beyond the territorial sea and gives a different, more limited set of rights. Ships and aircraft from other states generally retain freedom of navigation and overflight in the EEZ. This difference is why a statement that a foreign vessel entered another country’s EEZ does not automatically mean it entered sovereign territorial waters unlawfully.
A contiguous zone may extend beyond the territorial sea to a maximum of 24 nautical miles from the baseline, allowing specified enforcement related to customs, fiscal, immigration and sanitary laws. These zones overlap geographically in some respects but serve different legal purposes. A useful classroom comparison asks what a coastal state can regulate in each zone: fishing, navigation, customs and scientific research do not all follow the same rules. The answer depends on the specific legal category rather than a vague label such as national waters.
What rights does a coastal state have in its EEZ?
UNCLOS Article 56 grants sovereign rights for exploring, exploiting, conserving and managing living and non-living natural resources. Living resources include fish stocks, while non-living resources include certain oil, gas and mineral deposits. Coastal states may also regulate relevant energy activities, installations and aspects of marine scientific research and environmental protection. These rights can support employment, food security and government revenue. However, they also create responsibilities to manage resources and have due regard for other states’ rights.
The word sovereign rights is deliberate. It describes authority for particular purposes, not unrestricted control over all activities. For example, a coastal state cannot simply treat the EEZ as a 200-mile extension of its land borders. International law balances economic jurisdiction with the wider community’s interest in navigation and communications. This balance helps explain why maritime disagreements can involve several different questions at once: who may fish, who may drill, which ships may pass and what environmental rules apply.
Why are fisheries so important?
Fish stocks are a source of food and income for coastal communities. An EEZ allows a state to establish rules for fishing, including licensing, quotas and conservation measures, subject to international obligations. The aim is not only to claim economic value but also to manage resources that can be depleted by excessive harvesting. Fish do not recognise national boundaries, however. Many species move between EEZs and the high seas, requiring cooperation among neighbouring states and regional fisheries organisations.
Illegal, unreported and unregulated fishing can undermine conservation and livelihoods. Monitoring may involve vessel tracking, inspections and cooperation between authorities. Enforcement is challenging across large ocean areas, especially for states with limited resources. A good analysis distinguishes the legal right to manage fisheries from the practical ability to monitor every vessel. It should also consider small-scale fishing communities, whose needs may differ from those of large industrial fleets.
How do offshore oil, gas and wind power fit in?
Offshore oil and gas exploration can be economically important where deposits are commercially recoverable. But a map of geological potential is not proof of an active field or a proven reserve. Exploration, appraisal and production are different stages, and costs and environmental risks may prevent development. The EEZ framework provides rights over relevant resources, while the continental shelf regime is particularly important for seabed and subsoil resources. Offshore wind farms and other marine energy installations raise additional questions about planning, environmental impacts and shipping routes.
These activities may generate revenue and energy security benefits, but they can also affect marine habitats, fisheries and coastal communities. Governments must assess the likely consequences of construction and operation, and international cooperation may be necessary near boundaries. The economic importance of a claim therefore depends on what resources actually exist and can be developed, not merely on the area of sea shown on a map. This distinction helps prevent exaggerated statements about supposed offshore wealth.
What is the continental shelf, and how is it different?
The continental shelf has both a geological meaning and a legal meaning. Geologically, it is the relatively shallow submerged margin of a continent. Legally, UNCLOS defines rights over the seabed and subsoil according to rules that can extend beyond the physical shallow shelf. Coastal states have rights to explore and exploit resources of their legal continental shelf, and in certain circumstances the outer limit can extend beyond 200 nautical miles. This does not automatically extend the EEZ water-column rights to the same distance.
The difference matters for resources such as seabed minerals and offshore oil. A state might have rights over part of the seabed beyond 200 nautical miles while the waters above remain subject to high-seas freedoms. Legal claims beyond 200 miles involve technical submissions and rules about the outer limits of the continental shelf. Earth Site’s account of the geography of Angola and its strategic importance provides a practical example of why a long coastline and marine resources matter to a coastal state.
Why do EEZs overlap?
Two states with coasts less than 400 nautical miles apart may have potential EEZ entitlements that overlap. Islands and complex coastlines can make the situation more complicated. UNCLOS Article 74 calls for delimitation by agreement on the basis of international law to achieve an equitable solution. Courts and tribunals have developed methods for considering relevant circumstances, but there is no universal rule that every dispute is settled by drawing a simple line exactly halfway between the coasts.
A state may publish a map of its claim, but publication alone does not make the boundary internationally agreed. A negotiated treaty, a court judgment and a unilateral claim have different legal significance. This is particularly important when maps show competing colours over the same area. A careful article identifies which claims are disputed and avoids treating one government’s preferred line as a settled fact. Legal uncertainty can coexist with practical arrangements for fishing or resource development.
Can islands generate EEZs?
Under UNCLOS, islands generally have maritime entitlements, but Article 121 distinguishes islands from rocks that cannot sustain human habitation or economic life of their own. Such rocks do not generate an EEZ or continental shelf of their own. The interpretation of these provisions can become controversial when states dispute the status of small maritime features. Artificial islands do not have the same legal status as natural islands and do not generate their own territorial sea or EEZ simply because they have been constructed.
These distinctions help explain some disputes in the South China Sea and elsewhere. A small feature may have strategic significance out of proportion to its land area because maritime entitlements are potentially extensive. Yet the existence of a dispute does not determine the legal outcome. Evidence about a feature’s natural condition, relevant treaties and international judgments must be assessed. Earth Site’s account of the Bakassi Peninsula dispute between Nigeria and Cameroon illustrates how land sovereignty and adjacent maritime claims can interact.
Do foreign ships need permission to cross an EEZ?
As a general principle, foreign vessels retain freedom of navigation in another state’s EEZ, subject to relevant international rules and the requirement to have due regard for the coastal state’s rights. This is not the same as a licence to fish or exploit resources. Merchant ships commonly cross EEZs while travelling between ports. Submarine cables and pipelines also fall within a framework of international rights and duties. Disputes can arise over the interpretation of particular activities, especially where security concerns or contested maritime boundaries are involved.
The most useful way to understand such incidents is to ask exactly what the vessel was doing and which zone it entered. Passing through, conducting marine scientific research and extracting resources are legally different activities. A headline saying that a ship was inside a country’s 200-mile zone leaves out information needed to judge whether an international rule was broken. Precise terminology reduces unnecessary confusion in discussions of maritime security.
How are maritime disputes resolved?
States can negotiate boundaries, create provisional arrangements or submit certain disputes to international courts or arbitration, depending on the legal circumstances. The International Tribunal for the Law of the Sea, the International Court of Justice and arbitral tribunals can play roles under relevant procedures. Agreements may establish a boundary or allow joint management while sovereignty questions remain unresolved. Practical cooperation can be valuable where fisheries and ecosystems cross borders, even if governments continue to disagree about their legal claims.
Dispute resolution is rarely a purely technical exercise. Geography supplies coastlines and distances, while law determines which features and circumstances matter. Politics affects whether states accept proposals and implement agreements. The most durable arrangements often combine legal clarity with practical mechanisms for communication and resource management. Students should therefore distinguish three questions: what the convention says, what a government claims and what other states or tribunals have accepted.
Why do EEZs matter to environmental protection?
Marine pollution, overfishing and habitat damage can cross maritime boundaries. Coastal states have defined responsibilities and jurisdiction within their EEZs, but environmental management often requires cooperation across wider seas. Migratory species may move through several zones, and oil spills or plastic waste do not stop at legal lines. Protected areas and fisheries management can be effective only when they reflect ecological processes as well as jurisdictional boundaries.
Climate change adds further challenges by altering ocean temperatures, currents and species distributions. Fish stocks may shift towards different waters, potentially changing economic interests. Offshore energy projects may expand, bringing new demands for space and environmental assessment. The EEZ framework provides a way to allocate certain rights and duties, but it cannot replace scientific monitoring or international cooperation. Its importance lies in how law helps societies manage a shared physical environment.
Conclusion
An exclusive economic zone is best understood as a defined area of economic rights and responsibilities, not an extension of complete national sovereignty. The 200-nautical-mile limit, freedoms of navigation and rules for overlapping claims create a balance between coastal interests and wider ocean use. Knowing these distinctions helps readers interpret maritime disputes, resource claims and environmental decisions without confusing geography, law and politics.
Frequently asked questions
How many kilometres is 200 nautical miles?
It is 370.4 kilometres, because one nautical mile equals 1.852 kilometres.
Is an EEZ part of a country’s territory?
No. A coastal state has specified economic rights and jurisdiction, but the zone is not equivalent to land territory or the territorial sea.
Can foreign ships sail through an EEZ?
Generally yes, subject to applicable international law and due regard for the coastal state’s rights.
Can an EEZ extend beyond 200 nautical miles?
No. The EEZ limit is 200 nautical miles, although legal continental shelf rights over the seabed can extend farther in some circumstances.
What happens when two EEZ claims overlap?
States are expected to seek delimitation by agreement under international law, and disputes may involve negotiation or adjudication.
