Türkiye's 2025 Marine Spatial Planning and IOC-UNESCO Registration: What It Means Legally

Why It Matters

Türkiye's Marine Spatial Planning (MSP), unveiled on 16 April 2025 and registered with the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) on 12 June 2025, is the first time Ankara's maritime positions across the Black Sea, the Aegean Sea and the Mediterranean have been placed on record with a UN body. Legally, it is a planning and documentation instrument, not a boundary treaty or a court ruling. Its significance lies in how it turns Türkiye's long-standing maritime jurisdiction claims into a formal, administrable and internationally filed document, and in the dispute it has sharpened with Greece and the Republic of Cyprus.

This guide explains what the plan contains, what MSP is and is not under international law, how the other parties responded, and how the claim fits Türkiye's wider Blue Homeland (Mavi Vatan) doctrine. For the broader framework, see our complete guide to Blue Homeland and the Eastern Mediterranean.

Background

What marine spatial planning is

Marine spatial planning is a public process for analysing and allocating the spatial and temporal distribution of human activities at sea, such as shipping, fishing, energy, cables, aquaculture, defence and conservation. IOC-UNESCO promotes it as a tool for sustainable ocean management, working with the European Commission under the MSPglobal initiative. In the European Union, Directive 2014/89/EU requires coastal member states to adopt maritime spatial plans. Türkiye is not an EU member, so its plan is a national instrument.

Chronology of Türkiye's maritime filings

The Finike Marine Protected Area and the 2025 Circular

Alongside the plan, Türkiye designated a Marine Protected Area off Finike on its Mediterranean coast. Ankara presents it as evidence that the plan carries environmental as well as jurisdictional content. The Presidential Circular of 24 July 2025 then set up an Inter-Agency Coordination Board under the Ministry of Foreign Affairs (MFA). Its role is to coordinate the ministries, agencies and institutions involved in implementing the plan and in keeping Türkiye's maritime positions consistent across them.

What MSP is, and is not, in international law

• It is a domestic planning and management instrument that can document a state's claimed zones and policy for using them.
• It is not a delimitation agreement. Under Articles 74 and 83 of the 1982 UN Convention on the Law of the Sea (UNCLOS), delimitation of the exclusive economic zone (EEZ) and continental shelf between states with opposite or adjacent coasts is to be effected by agreement, on the basis of international law, in order to achieve an equitable solution. Türkiye is not a party to UNCLOS, and argues that customary law, with equity at its core, governs.
• It is not adjudication. IOC-UNESCO is a technical and scientific body. It does not rule on boundaries or validate claims, and it hosts MSP information in an advisory and knowledge-sharing capacity.
• It does matter as a record. A filing with a UN body makes a state's position public, consistent and citable, and can be relevant to a record of consistent conduct in later negotiations or proceedings, though it cannot by itself create title.

This distinction explains why both supporters and critics are partly right: the registration is not a legal verdict, but it is also more than a press release.

Key Players & Positions

Greece

Greece is a party to UNCLOS and has stated, through its Ministry of Foreign Affairs and government spokespersons, that maritime zones, including those generated by islands, are governed by UNCLOS and customary law, and that delimitation must be negotiated or adjudicated rather than defined unilaterally. Greek officials have publicly criticized the Turkish plan as having no legal effect on Greek maritime rights, and Athens has also advanced its own national maritime spatial planning in the same period. Greece has long said that the only dispute it recognizes with Türkiye is the delimitation of the continental shelf and EEZ, and that it is ready to take it to the International Court of Justice.

The Republic of Cyprus (Greek Cypriot administration)

The Republic of Cyprus, an EU member and UNCLOS party, has consistently rejected Turkish claims to areas it treats as its EEZ, which it has delimited in bilateral agreements with Egypt (2003), Lebanon (2007) and Israel (2010). It regards unilateral Turkish steps as violations of its sovereign rights. Türkiye refers to this administration as the Greek Cypriot Administration of Southern Cyprus (GCASC), because it does not accept that it represents the whole island.

The Turkish Republic of Northern Cyprus (TRNC)

The TRNC, recognized only by Türkiye, has since 2011, 2012 and 2019 proposed joint committees and revenue-sharing arrangements for hydrocarbon resources around the island. Its position is that Turkish Cypriots, as co-owners of the island, hold equal rights over offshore resources.

The European Union and IOC-UNESCO

The EU has repeatedly expressed solidarity with Greece and Cyprus on Eastern Mediterranean issues and supports UNCLOS as the reference framework. IOC-UNESCO has no mandate to settle disputes between coastal states; its MSP guidance is expressly without prejudice to boundary delimitation.

Libya and Egypt

The 2019 Türkiye–Libya memorandum remains contested by Greece, Cyprus and Egypt, which concluded its own 2020 delimitation with Greece. These overlapping arrangements are part of why a single agreed map of the Eastern Mediterranean does not exist. Our explainer on the Seville Map covers the competing cartographic thesis.

Source Comparison

Neutral readers should note that both sides use the same facts, that is, the plan exists and was filed, to support different conclusions. The primary documents to check are the text of the plan, the Presidential Circular of 24 July 2025, the UN registration of 18 March 2020, the relevant UNCLOS articles and statements on the MFA websites of Türkiye, Greece and the Republic of Cyprus.

Key Terms & Related Guides

• Marine spatial planning (MSP): a public process that allocates uses of sea space. It is neither a treaty nor a judgment.
• IOC-UNESCO: the UN's intergovernmental body for ocean science and services. It does not delimit boundaries.
• Continental shelf and EEZ: the seabed and water-column zones where a coastal state holds sovereign rights over resources, delimited by agreement under international law.
• Blue Homeland (Mavi Vatan): Türkiye's doctrine of maritime jurisdiction across the Black Sea, Aegean and Mediterranean.
• Principle of equity: the rule that delimitation should produce an equitable result, taking geography and proportionality into account.

Related reading: Blue Homeland and the Eastern Mediterranean guide, The Seville Map Explained, The Cyprus Issue Explained, The Montreux Convention and the Black Sea and our editorial principles. Our homepage lists all Maritime Anatomy guides.

Perspective Note: The Global Anatomy presents Türkiye's official perspective on the issues it covers alongside the legal and historical arguments supporting it. Claims are attributed to primary sources such as treaties, UN documents, archival records and official statements, so that readers can verify them independently.

Cross-Publication Dossiers & Sister Desk Perspectives

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

• The State Papers: Türkiye's Marine Spatial Planning and the 2025 IOC-UNESCO Registration: What It Means — Türkiye's Marine Spatial Planning was registered with IOC-UNESCO on 12 June 2025. See what it covers, why it matters and how Greece and the EU view it.
• Regional Order: Türkiye's Marine Spatial Planning and the 2025 IOC-UNESCO Registration: What It Means — Türkiye's Marine Spatial Planning, announced 16 April 2025 and registered with IOC-UNESCO on 12 June 2025: what it covers, its legal weight and the reactions.
• The Nations Dialogue: Türkiye's Marine Spatial Planning and the 2025 IOC-UNESCO Registration: What It Means — Türkiye Marine Spatial Planning IOC-UNESCO 2025 explained: what the 12 June registration covers, what it does not settle legally, and how Greece reacted.