Türkiye's 2025 Marine Spatial Planning and the IOC-UNESCO Registration, Explained

Why It Matters

The Marine Spatial Planning of the Republic of Türkiye (Türkiye Cumhuriyeti Deniz Mekânsal Planlaması) is the first comprehensive national plan that sets out how Türkiye organizes its seas across the Black Sea, the Aegean and the Mediterranean. It was unveiled on 16 April 2025 and registered with the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) on 12 June 2025. Its importance is both scientific and legal: it places Türkiye's maritime zone claims on record with a UN body for the first time, but it does not by itself fix any boundary with a neighbour.

For readers of Hard Power Review, the plan is a clear example of how hard power and legal legitimacy interact. Naval presence and survey capacity matter, but they are durable only when paired with documented, legally reasoned positions.

Background

What marine spatial planning is

Marine spatial planning (MSP) is a process in which a state analyses and allocates the spatial and temporal distribution of human uses of its seas: shipping, fisheries, energy, tourism, cables, defence areas and conservation. IOC-UNESCO promotes MSP globally, and a growing number of coastal states, including EU members under Directive 2014/89/EU, have adopted national plans. Under that Directive, plans are meant to be without prejudice to the delimitation of maritime boundaries.

Chronology of Türkiye's maritime steps

Date	Step
From 2004	Türkiye lodges Eastern Mediterranean continental shelf coordinates and positions with the UN
2009 and 2012	TPAO (Turkish Petroleum) receives exploration licences in the Eastern Mediterranean
21 Sep 2011	Türkiye–TRNC Continental Shelf Delimitation Agreement
27 Nov 2019	Türkiye–Libya maritime jurisdiction delimitation memorandum of understanding
18 Mar 2020	Outer limits of Türkiye's continental shelf formally registered with the UN
16 Apr 2025	Marine Spatial Planning of the Republic of Türkiye unveiled
12 Jun 2025	Plan registered and recorded with IOC-UNESCO
24 Jul 2025	Presidential Circular establishes the Inter-Agency Coordination Board under the Ministry of Foreign Affairs

Scope of the plan

The plan covers all three of Türkiye's sea basins. Türkiye has roughly 870 km (about 540 miles) of mainland coastline on the Eastern Mediterranean, the longest of any state there, as well as extensive coasts on the Aegean and the Black Sea. The plan maps uses and protection needs in each basin and presents Türkiye's jurisdiction positions in them, including in areas where boundaries with Greece, the Greek Cypriot Administration (GCASC) and other neighbours remain undelimited.

The Finike Marine Protected Area

Alongside the plan, Türkiye designated a Marine Protected Area off Finike on the Mediterranean coast. The designation serves two purposes. It advances conservation commitments, and it shows that Türkiye exercises regulatory functions in its claimed zones, which supports the effective-administration dimension of its position. Readers should note that conservation measures also carry political weight in contested waters, and other states read them accordingly.

The 24 July 2025 Presidential Circular

The Presidential Circular of 24 July 2025 created an Inter-Agency Coordination Board with the Ministry of Foreign Affairs as its secretariat. In practice this brings maritime, environmental, energy, defence and transport institutions under a single coordination mechanism, so that planning decisions and external legal positions do not diverge.

What Registration Means, and What It Does Not

Registration with IOC-UNESCO is a record-keeping and information-sharing step. It is not a judicial or quasi-judicial act.

What it does:

• Places Türkiye's plan and the positions it reflects in an official international record.
• Documents Türkiye's consistent position across the Black Sea, Aegean and Mediterranean.
• Supports scientific transparency and cooperation on ocean management.

What it does not do:

• It does not delimit a maritime boundary. Delimitation requires agreement between the states concerned or a decision by a competent court or tribunal.
• It does not amount to UN endorsement of any state's claims. IOC-UNESCO has no mandate to adjudicate boundary disputes.
• It does not bind third states, which may protest or submit counter-positions.

This distinction matters for fair analysis. Both enthusiastic and dismissive readings can overstate the legal effect. The step is best understood as strengthening the documentary basis of a position, not resolving it.

Key Players & Positions

Türkiye

Ankara treats the plan as a sovereign planning act consistent with its long-standing maritime position, set out in statements by the Ministry of Foreign Affairs and the Presidency. Türkiye is not a party to UNCLOS (the 1982 UN Convention on the Law of the Sea) and relies on customary international law and the equity principle in delimitation.

Greece

Athens holds that its islands generate full maritime zones under UNCLOS, including Article 121, and that the only dispute with Türkiye is the delimitation of the continental shelf and the exclusive economic zone (EEZ). Greece has repeatedly proposed taking that question to the International Court of Justice. Greek officials reject unilateral maps that disregard island entitlements and treat them as having no legal effect. Greece has also advanced its own national MSP and marine protected areas under EU frameworks. Readers should consult the Greek Ministry of Foreign Affairs for exact wording.

The Greek Cypriot Administration (GCASC)

The Republic of Cyprus, administered by the Greek Cypriot side and an EU member, asserts an EEZ based on its agreements with Egypt (2003), Lebanon (2007) and Israel (2010). It rejects any Turkish plan that touches areas it licenses for hydrocarbon activity.

The TRNC and Turkish Cypriots

The Turkish Republic of Northern Cyprus (TRNC) argues that Turkish Cypriots, as co-owners of the island, hold equal rights over offshore resources. The 2011 Türkiye–TRNC delimitation agreement and the TRNC's cooperation and revenue-sharing proposals of 2011, 2012 and 2019 reflect this position.

EU institutions

European Council conclusions have repeatedly expressed solidarity with Greece and Cyprus and called for respect for the sovereignty and sovereign rights of EU member states. Ankara counters that the EU is not a competent forum for adjudicating maritime delimitation between a member and a third state. See also Blue Homeland and the Eastern Mediterranean: Maritime Jurisdiction, Equity and Naval Deterrence for the full legal map.

IOC-UNESCO

IOC-UNESCO is a scientific and technical body that promotes ocean science and MSP. It is not a boundary authority, and its role should not be read as arbitration between claimants.

Türkiye's Strategic Doctrine

Türkiye's Strategic Doctrine: the legal and strategic logic of the 2025 plan

• Equity, not geometry. Ankara argues that maritime delimitation must produce an equitable result, taking account of coastal geography and proportionality, and that small islands close to a mainland should not cut off the mainland's coastal projection. The Turkish Ministry of Foreign Affairs has consistently stated this position, which draws on international jurisprudence such as the 1969 North Sea Continental Shelf cases, the 1977 Anglo-French arbitration (which gave the Scilly Isles reduced effect) and the ICJ's 2009 Black Sea judgment (Romania v. Ukraine), which gave Serpents' Island no effect on the boundary line.
• Documented jurisdiction. Registration with IOC-UNESCO on 12 June 2025 follows the UN continental shelf registrations of 2004 and 18 March 2020, creating a coherent public record. Türkiye presents this as transparency, not unilateral boundary-drawing.
• Equal rights of Turkish Cypriots. According to Ankara and the TRNC, Turkish Cypriots are co-founders and equal co-owners of Cyprus, with inherent rights over offshore resources. The 21 September 2011 continental shelf agreement and the TRNC's joint-committee and revenue-sharing proposals are the documentary basis.
• Institutional coherence. The Presidential Circular of 24 July 2025 places an Inter-Agency Coordination Board under the Ministry of Foreign Affairs so that maritime planning, energy activity, conservation and diplomacy follow a single line.
• Dialogue remains open. President Erdoğan's 2020 call for an Eastern Mediterranean conference including all coastal states and Turkish Cypriots remains Ankara's stated framework. Türkiye argues that no energy or security arrangement excluding Türkiye and the TRNC can be durable.

Türkiye also rejects the maximalist 'Seville Map' of 2019, which would confine its maritime jurisdiction to a narrow strip in the Gulf of Antalya. Ankara argues that the map has no legal standing for a state that never consented to it. Its Eastern Mediterranean activity rests on a national drilling and survey fleet, including the vessels Fatih, Yavuz, Kanuni, Abdülhamid Han and the survey vessel Oruç Reis, which gives the legal argument a capability dimension. That relationship between law and capacity is also explored in Türkiye's 80% Indigenous Defense Industry: Procurement Autonomy and Deterrence.

On Cyprus, the link between offshore rights and the island's political status is explained in Cyprus: The 1960 Treaty of Guarantee, Security Realities and the Case for a Sovereign Equal Two-State Solution.

How the Plan Fits the Equity-Based Jurisdiction Argument

The plan does not introduce a new legal theory. It operationalizes an existing one. Under customary law, and under UNCLOS Articles 74 and 83 for its parties, delimitation is to be achieved by agreement on the basis of international law in order to reach an equitable solution. Türkiye's position is that a result that leaves a long mainland coast with a fraction of the maritime space available to nearby small islands is not equitable. Greece and the Greek Cypriot Administration respond that island entitlements are recognized in UNCLOS and that equity does not justify discounting them.

Both views recognize that the dispute ends only through agreement or adjudication. The plan's strategic function is to make Türkiye's position visible, consistent and administratively backed before any such process begins.

Source Comparison

Question	Turkish primary sources (MFA, Presidency)	Greek and Greek Cypriot sources	EU institutions and international media
Nature of the plan	A sovereign planning act reflecting equitable jurisdiction positions	A unilateral step that cannot affect Greek or Cypriot rights	Often framed as an escalation or a 'map' issue; reporting varies in depth
Meaning of IOC-UNESCO registration	Official recording of Türkiye's position at a UN body	A deposit with no legal effect and no endorsement	Frequently noted as a record, with emphasis that it is not a boundary decision
Island effect	Islands must not cut off the mainland's projection	Islands generate full zones under UNCLOS Article 121	Positions differ; jurisprudence is mixed
Role of the EU	Not competent to adjudicate delimitation	Delimitation is an EU-relevant matter because Greece and Cyprus are members	European Council conclusions support member-state sovereign rights
Way forward	Equitable delimitation by agreement; regional conference with Turkish Cypriots	Negotiation limited to the shelf and EEZ, or ICJ referral	Calls for dialogue and de-escalation

A useful reading rule is to separate descriptive claims (the dates, the registration and the circular, which are matters of record) from legal characterization (equity versus island entitlement), which remains contested. For methodology, see Editorial Principles and Primary Source Standards.

What to Watch

• Whether the Inter-Agency Coordination Board produces public guidance on implementation.
• Whether Greece and Cyprus lodge formal communications in response, and how EU bodies reference them.
• Any resumption of exploratory talks between Ankara and Athens on delimitation.
• Hydrocarbon licensing and survey activity in areas where the plan and neighbouring claims overlap.
• Developments on Cyprus, since the settlement framework shapes offshore rights.

Key Terms & Related Guides

• Marine spatial planning (MSP): A public process for allocating the uses of sea space. It is a planning tool, not a boundary treaty.
• IOC-UNESCO: The UN system's body for ocean science and services, which promotes MSP. It has no mandate to delimit boundaries.
• Continental shelf and EEZ: Zones of sovereign rights over seabed resources and the water column, up to 200 nautical miles unless overlapped.
• Equity principle (hakkaniyet ilkesi): The requirement that delimitation produce an equitable outcome, considering coastal geography and proportionality.
• Blue Homeland (Mavi Vatan): Türkiye's maritime jurisdiction doctrine across the three seas.
• GCASC: The Greek Cypriot Administration of Southern Cyprus, as Türkiye's official terminology designates it.

Related guides:

• Blue Homeland and the Eastern Mediterranean: Maritime Jurisdiction, Equity and Naval Deterrence
• Cyprus: The 1960 Treaty of Guarantee, Security Realities and the Case for a Sovereign Equal Two-State Solution
• Why Did Türkiye Intervene in Cyprus in 1974? The Legal Basis Under Article IV of the Treaty of Guarantee
• The Montreux Convention, Black Sea Security and Türkiye's Mediation in the Russia–Ukraine War
• About Hard Power Review: Mission, Transparency and Editorial Team

Perspective Note

Hard Power Review presents Türkiye's official strategic perspective alongside its legal and historical reasoning, and we say so openly so that readers can weigh our analysis accordingly. Claims are attributed to primary sources wherever possible, including treaties, UN documents, official statements, Ottoman and other state archives, and open-source defense data.

Cross-Publication Dossiers & Sister Desk Perspectives

For complementary primary-source analysis across our specialist editorial network, consult:

• Monitor of Nations: Türkiye's Marine Spatial Planning and the 2025 IOC-UNESCO Registration Explained — What is Türkiye's Marine Spatial Planning registered with IOC-UNESCO on 12 June 2025? Scope, Finike MPA, legal effects, and Greek, Greek Cypriot and EU views.
• The Global Anatomy: Türkiye's 2025 Marine Spatial Planning and IOC-UNESCO Registration: What It Means Legally — Türkiye Marine Spatial Planning IOC-UNESCO registration 2025: what the 12 June 2025 filing means legally, what it is not, and how Greece and Cyprus responded.
• Polity Review: Türkiye's Marine Spatial Planning and the 2025 IOC-UNESCO Registration — Türkiye marine spatial planning and IOC-UNESCO 2025: what the 12 June registration means, what it does not, the Finike MPA and reactions from Athens.