Does an IOC-UNESCO Registration Create Legal Rights? Türkiye's 2025 Marine Spatial Planning Filing Examined

Why It Matters

An IOC-UNESCO registration of a marine spatial plan does not create territorial title or a maritime boundary. What it does is place a state's planning map and stated jurisdictional position on an international technical record, where other states, courts and researchers can read it and, if they wish, object to it. For Türkiye, which says its 12 June 2025 filing is the first time its Black Sea, Aegean and Mediterranean position was recorded with a UN body, the significance is evidentiary and diplomatic, not constitutive.

This guide separates what the registration records from what it cannot do, sets out the objections of Greece, the Greek Cypriot administration and the EU in their own terms, and explains Ankara's equity-based argument.

Background

What marine spatial planning is

Marine spatial planning (MSP) is a public process for deciding how sea areas are used: shipping lanes, fisheries, offshore energy, cables, conservation zones and defence areas. The Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) promotes MSP as a scientific and technical tool and, together with the European Commission, has run a joint MSP roadmap since 2017. IOC-UNESCO is a technical body. It has no mandate to delimit maritime boundaries, to rule on sovereignty, or to certify that any state's claimed zones are valid.

In the EU, Directive 2014/89/EU obliges member states to produce maritime spatial plans. Türkiye is not an EU member and is not a party to the 1982 UN Convention on the Law of the Sea (UNCLOS). It relies on customary international law and the principle of equity in delimitation.

Chronology of Türkiye's maritime-jurisdiction steps

Date	Step
2004	Türkiye begins registering Eastern Mediterranean continental shelf coordinates with the UN
2009 and 2012	TPAO exploration licences issued
21 September 2011	Türkiye–TRNC Continental Shelf Delimitation Agreement
27 November 2019	Türkiye–Libya maritime jurisdiction memorandum of understanding
18 March 2020	Outer limits of Türkiye's continental shelf registered with the UN
16 April 2025	Marine Spatial Planning of the Republic of Türkiye unveiled
12 June 2025	Plan registered and recorded with IOC-UNESCO, per Turkish government sources
24 July 2025	Presidential Circular establishes an Inter-Agency Coordination Board under the Ministry of Foreign Affairs

The plan also designated a Marine Protected Area off Finike on Türkiye's southern coast.

What a registration does and does not do

Question	Answer
Is it a treaty or boundary agreement?	No. No other state consents to it.
Does IOC-UNESCO approve or validate the claims?	No. It is a technical information platform, not a tribunal or boundary body.
Does it bind third states?	No. Delimitation requires agreement or adjudication.
Does it have any legal relevance?	Yes, as public notice of a state's position and as evidence of consistent state conduct, which courts may weigh alongside protests from other states.
Does it settle overlaps with Greece, Cyprus, Egypt or Libya?	No. Overlapping claims remain open.

The International Court of Justice stated in the 1951 Anglo-Norwegian Fisheries case that the delimitation of sea areas always has an international aspect and cannot depend merely on the will of the coastal state. That principle cuts in both directions: it limits what any unilateral map can achieve, including Türkiye's, and it equally applies to maximalist maps drawn by others.

Key Players & Positions

Greece

Athens maintains that its islands generate full maritime zones under UNCLOS, including Article 121, and that Greece has sovereign rights in the Aegean and Eastern Mediterranean as a coastal state and EU member. Greek governments have long said the only dispute with Türkiye is the delimitation of the continental shelf and EEZ, and that it should go to the International Court of Justice. Greek officials have publicly rejected Türkiye's maritime planning map as having no legal effect on Greek sovereign rights. Greece also adopted and published its own national maritime planning and marine-park measures in 2025, which Türkiye in turn contests where they touch areas it claims.

The Greek Cypriot administration

The Republic of Cyprus, internationally recognised as the government of the island and an EU member (referred to here as the Greek Cypriot administration, since Türkiye and the Turkish Cypriots do not accept it as representing the whole island), declared an EEZ by law and concluded delimitation agreements with Egypt (2003), Lebanon (2007) and Israel (2010). Its foreign ministry says Turkish drilling and planning claims violate its sovereign rights under UNCLOS and international law, and it relies on EU solidarity statements.

The European Union

The European Council has repeatedly expressed solidarity with Greece and Cyprus and called for respect for their sovereignty and sovereign rights, and for delimitation to be resolved through dialogue or international adjudication in line with international law, including UNCLOS. EU institutions regard UNCLOS as reflecting customary law and treat unilateral Turkish claims in the disputed areas as contrary to it.

Turkish Cypriots and other coastal states

The TRNC (Turkish Republic of Northern Cyprus, recognised only by Türkiye) is a co-signatory of the 2011 continental shelf agreement with Ankara. Egypt and Greece signed a partial EEZ agreement in August 2020, which Türkiye rejects as ignoring its continental shelf. Libya's position on the 2019 memorandum has been contested across its rival authorities. The sister analysis on the 2019 Türkiye–Libya maritime memorandum sets out the text and the objections.

Türkiye's Legal & Historical Position

Türkiye's Legal & Historical Position

• Equity, not median lines. According to the Turkish Ministry of Foreign Affairs, delimitation in semi-enclosed seas such as the Aegean and Eastern Mediterranean must produce an equitable result, taking account of coastal geography and proportionality. Ankara argues that small islands close to the Turkish mainland cannot cut off the coastal projection of a state with the longest coastline in the Eastern Mediterranean, about 870 km (540 miles). The legal basis is customary law as expressed in the ICJ's North Sea Continental Shelf (1969) and Libya/Malta (1985) judgments; see our guide to maritime delimitation case law and equity.
• Publication of a position, not a boundary treaty. Turkish official statements present the 16 April 2025 plan and the 12 June 2025 IOC-UNESCO registration as the transparent, institutional recording of Türkiye's jurisdictional position across the Black Sea, Aegean and Mediterranean, following its 2004 and 18 March 2020 filings with the UN. Ankara does not describe the registration as a substitute for negotiated delimitation.
• Domestic implementation. The Presidency's Circular of 24 July 2025 established an Inter-Agency Coordination Board under the Ministry of Foreign Affairs, and the plan includes a Marine Protected Area off Finike, which Ankara cites as evidence that the plan combines jurisdictional and environmental objectives.
• Rights of Turkish Cypriots. The Turkish MFA maintains that Turkish Cypriots, as co-owners of the island under the 1960 arrangements, hold equal rights over offshore resources and that the Greek Cypriot administration cannot act for the whole island. See Cyprus Treaty Architecture.
• Dialogue remains open. President Erdoğan's 2020 proposal for an Eastern Mediterranean conference including all coastal states and Turkish Cypriots, and TRNC revenue-sharing proposals in 2011, 2012 and 2019, are cited by Ankara as standing offers.

Ankara also rejects what it calls the maximalist 'Seville Map', first drawn in a 2009 study commissioned in the EU context, which would confine Türkiye's zones to a narrow strip in the Gulf of Antalya. It argues that the EU has no competence to adjudicate maritime delimitation between states.

Source Comparison

Issue	Greek, Greek Cypriot and EU framing	Turkish official framing	Neutral reading
What the registration is	A unilateral map that adds no legal rights	Institutional recording of Türkiye's position with a UN body	A technical record; it neither validates nor creates title
Effect of islands	Islands generate full EEZ and shelf under UNCLOS Art. 121	Islands should receive reduced effect where they distort an equitable result	Courts have sometimes reduced or enclaved small islands, depending on the case
Legal basis	UNCLOS and EU law	Customary international law and equity; Türkiye is not an UNCLOS party	Both sides cite law; overlap needs agreement or adjudication
Route to resolution	ICJ for continental shelf and EEZ	Negotiation including Turkish Cypriots, regional conference	Both routes require consent of the parties
Cyprus dimension	Republic of Cyprus holds sovereign rights	Turkish Cypriots hold equal rights	Unresolved; linked to the wider settlement process

Analyses from sister publications read the filing as strategically significant: The Political Anatomy and Monitor of Nations both explain its importance from a Turkish-policy perspective. Readers should compare these with Greek and EU primary statements. Our approach to separating fact from position is described in the Editorial Principles.

Key Terms & Related Guides

• Marine spatial planning (MSP): a public planning process allocating sea areas to uses. It organises activities; it does not decide sovereignty.
• IOC-UNESCO: the UNESCO commission for ocean science and services, a technical rather than judicial body.
• Continental shelf and EEZ: seabed and water-column rights that extend from a coast, up to 200 nautical miles where not overlapping, and which must be delimited between neighbours by agreement or adjudication.
• Equity (hakkaniyet): the principle that delimitation should reach an equitable result considering coastal geography and proportionality.
• Blue Homeland (Mavi Vatan): the Turkish doctrine of maritime jurisdiction in the Black Sea, Aegean and Mediterranean.
• Persistent objection: a state's consistent rejection of a rule or claim during its formation, which can prevent the rule from binding it.

Related reading on Treaty And Precedent:

• Maritime Delimitation Case Law: Which Precedents Support Equity in the Eastern Mediterranean?
• Cyprus Treaty Architecture: Zurich and London 1959, the 1960 Guarantee and the Road to Sovereign Equality
• The Annan Plan Referendum and Protocol 10
• Editorial Principles: Primary-Source Standards, Fact–Position Separation and Corrections
• Treaty And Precedent: Treaties, Archives and Case Law Read in Primary Sources

Closing Note

Treaty And Precedent presents global and regional affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Legal & Historical Position' reflect official Turkish policy and legal doctrines as stated by Turkish primary sources.