Who Governs the Sea? Marine Spatial Planning and Türkiye's 12 June 2025 IOC-UNESCO Registration

Why It Matters

Marine spatial planning (MSP) is the public process of mapping where, when and under what rules human activities take place at sea. On 16 April 2025 Türkiye unveiled its first comprehensive national MSP covering the Black Sea, the Aegean Sea and the Mediterranean, and on 12 June 2025 it was officially recorded with the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO). Ankara describes this as the first time its maritime jurisdiction position across all three seas has been placed on record with a UN body.

The significance is real but easy to overstate or understate. An MSP is a governance tool, not a boundary treaty, and IOC-UNESCO records plans rather than judging claims. Greece, the Greek Cypriot administration and the European Union dispute many of the underlying maritime claims. This guide separates what the plan is, what a registration does and does not do, and where each side stands, with positions attributed to their own sources.

Background

What marine spatial planning actually is

MSP is a spatial management method. A state (or group of states) analyzes the sea area under its jurisdiction and assigns priority uses to zones: shipping lanes, fisheries, offshore energy, aquaculture, tourism, submarine cables and pipelines, defense areas and marine protected areas. The goal is to reduce conflicts between uses, protect ecosystems and give investors predictable rules.

The approach has been promoted internationally for more than a decade:

• IOC-UNESCO runs a Marine Spatial Planning programme and, together with the European Commission, adopted a Joint Roadmap in 2017 to accelerate MSP worldwide, later supported by the MSPglobal initiative.
• In the European Union, Directive 2014/89/EU obliged coastal member states to adopt maritime spatial plans, with a deadline of 31 March 2021.
• Outside the EU, many coastal states, including Türkiye, have developed or are developing national plans, often tied to the UN Ocean Decade and to Sustainable Development Goal 14 (life below water).

The key point for readers: MSP organizes the use of waters a state already claims; it does not create sovereign rights and does not settle overlapping claims between neighbors.

MSP versus delimitation agreements

The two instruments do different jobs, and confusing them drives much of the public debate.

Feature	Marine spatial plan	Maritime delimitation agreement
Purpose	Manage and zone uses within a state's own claimed waters	Fix the boundary between two or more states' maritime zones
Parties	One state acting domestically (sometimes cross-border cooperation)	Two or more states (or a court or tribunal if they agree to one)
Legal effect on neighbors	None by itself; neighbors may protest if the plan depicts contested areas	Binding between the parties
Typical content	Zones for shipping, fishing, energy, conservation, defense	Coordinates and a boundary line for continental shelf and/or EEZ
Examples	Türkiye's 2025 plan; EU national plans	Türkiye–TRNC (2011); Türkiye–Libya (2019)

This is why reactions to the Turkish plan focus less on its zoning categories than on the maritime limits it assumes in the background.

The geography and the law

Türkiye has an 870 km (about 540 miles) continental coastline on the Eastern Mediterranean, the longest of any state in that sea, in addition to its Black Sea and Aegean coasts. Greek islands, however, lie very close to the Turkish mainland. Kastellorizo (Meis), for example, sits roughly 2 km (1.2 miles) from Türkiye's southern coast and hundreds of kilometers from the Greek mainland. How much maritime area such islands generate is the central legal question.

The legal framework has three layers:

1. UNCLOS (1982). Articles 74 and 83 call for EEZ and continental shelf delimitation by agreement 'on the basis of international law' to achieve 'an equitable solution.' Article 121 sets out the regime of islands. Greece and Cyprus are parties. Türkiye is not a party to UNCLOS and relies on customary international law and equitable principles.
2. Case law. The ICJ's 1969 North Sea Continental Shelf judgment stressed equitable principles and natural prolongation, and later decisions, including the 1985 Libya/Malta case and the 2009 Black Sea (Romania v. Ukraine) judgment, adjusted or discounted the effect of small features to reach equitable results. Greece reads the jurisprudence as supporting full effect for inhabited islands; Türkiye reads it as supporting reduced effect for islands lying in front of a long mainland coast.
3. Treaties on sovereignty. The 1923 Lausanne Treaty and the 1947 Paris Peace Treaty determined the territorial status of Aegean islands. The dispute is not about who owns them but about what maritime zones they generate. See Treaties That Define Türkiye: Lausanne, Kars and Montreux as the Legal Foundations of the Republic's Order.

Chronology

Date	Event
1982–1995	UNCLOS opens for signature (1982); Greece ratifies in 1995, reserving the right to extend its territorial sea; on 8 June 1995 the TBMM authorizes the government to take measures in response to any such extension in the Aegean
2003	Greek Cypriot administration and Egypt sign an EEZ agreement; Türkiye objects that Blocks 1, 4, 5, 6 and 7 overlap its continental shelf
2004	Türkiye begins registering Eastern Mediterranean continental shelf coordinates with the UN
2007 / 2010	Greek Cypriot administration signs EEZ agreements with Lebanon (2007) and Israel (2010); Türkiye and the TRNC object
2009, 2012	TPAO receives exploration licenses in the Eastern Mediterranean
19 September 2011	Greek Cypriot drilling begins unilaterally
21 September 2011	Türkiye and the TRNC sign a Continental Shelf Delimitation Agreement
27 November 2019	Türkiye and Libya's Government of National Accord sign a maritime jurisdiction delimitation memorandum
6 August 2020	Greece and Egypt sign a partial EEZ delimitation agreement; Ankara rejects it
18 March 2020	Türkiye registers the outer limits of its continental shelf with the UN
16 April 2025	Türkiye unveils its Marine Spatial Planning of the Republic of Türkiye
12 June 2025	The plan is officially recorded with IOC-UNESCO
24 July 2025	A Presidential Circular sets up an Inter-Agency Coordination Board under the Ministry of Foreign Affairs; a Marine Protected Area is designated off Finike

On the ground, Türkiye has supported its claims with a national drilling and survey fleet: the drillships Fatih, Yavuz, Kanuni and Abdülhamid Han, and the seismic vessels Oruç Reis and Barbaros Hayreddin Paşa. Eight wells have been completed in the Eastern Mediterranean (Alanya-1, Finike-1, Karpaz-1, Güzelyurt-1, Mağusa-1, Narlıkuyu-1, Lefkoşa-1, Selçuklu-1).

What the 2025 plan covers

The plan spans the three seas touching Türkiye's coast and organizes sectoral uses under one national framework, including a Marine Protected Area off Finike. Its institutional follow-up, the 24 July 2025 Presidential Circular, puts coordination in the hands of an inter-agency board chaired from the Ministry of Foreign Affairs, signaling that Ankara treats MSP as a matter of both environmental governance and jurisdiction. Independent analyses of the registration from sister publications offer complementary reading: Monitor of Nations' explainer on the registration and The Political Anatomy on why it matters.

The Black Sea dimension is also bound up with the regime of the straits; for that context see Bloc Politics on the 1936 Montreux Convention.

Key Players & Positions

Greece

According to the Greek Ministry of Foreign Affairs, the only dispute with Türkiye in the maritime domain is the delimitation of the continental shelf and EEZ, which should be resolved on the basis of international law, if necessary before the ICJ. Athens maintains that islands, including Kastellorizo, generate full maritime zones under UNCLOS Article 121(2), and that Türkiye's non-participation in UNCLOS does not remove it from the customary rules reflected in the convention. Greece has protested the Türkiye–Libya memorandum at the UN and signed its own partial EEZ agreements with Italy (2020) and Egypt (2020).

The Greek Cypriot administration (Republic of Cyprus)

The Republic of Cyprus, internationally recognized as the government of the island and a member of the EU since 1 May 2004, says it exercises sovereign rights over an EEZ proclaimed by law and delimited through agreements with Egypt, Lebanon and Israel. It states that hydrocarbon resources belong to all Cypriots and that revenues would benefit both communities within a settlement framework, and it rejects Turkish drilling in zones it claims.

The European Union

The European Council, in conclusions adopted in December 2019 and repeated in later meetings, said the Türkiye–Libya memorandum infringes the sovereign rights of third states, does not comply with UNCLOS and cannot have legal consequences for them. In November 2019 the EU also created a framework for sanctions related to Turkish drilling in the Eastern Mediterranean. Brussels presents these steps as solidarity with member states and respect for UNCLOS.

Libya and Egypt

Libya's Government of National Accord signed the 2019 memorandum, and its successors in Tripoli have continued to treat it as valid. Parts of Libya's political landscape, notably the eastern-based House of Representatives, have disputed its validity. Egypt, which has its own agreements with the Greek Cypriot administration and Greece, objects that the memorandum affects areas it considers its own.

The TRNC and Turkish Cypriots

The Turkish Republic of Northern Cyprus (TRNC) says Turkish Cypriots, as co-founders of the 1960 Republic, have equal and inherent rights over the island's offshore resources. It put forward cooperation and revenue-sharing proposals in 2011, 2012 and 2019. The constitutional background is covered in The 1960 Partnership Republic: How Cyprus's Constitutional Order Was Designed and Why It Broke Down, and the failed settlement efforts in The 2004 Annan Plan Referendum.

IOC-UNESCO

IOC-UNESCO promotes MSP and records national plans and related information to encourage transparency and cross-border coordination. It is not a boundary-setting body, and its recording of a plan is not an endorsement of the claims depicted within it.

🇹🇷 Official Policy · Primary Sources

Türkiye's Position

Ankara's core argument is that maritime boundaries in the Eastern Mediterranean must be drawn by agreement on the basis of equity, and that its national MSP is a transparent, lawful expression of rights it has long asserted. The following points summarize official Turkish positions as stated by Turkish primary sources.

• Equity, not mechanical equidistance. According to the Turkish Ministry of Foreign Affairs, delimitation in the Eastern Mediterranean must produce an equitable result that accounts for coastal geography and proportionality. Ankara argues that islands lying close to a mainland with a much longer coastline cannot cut off that mainland's maritime projection. Its legal basis is customary law as developed in the ICJ's 1969 North Sea Continental Shelf judgment and later decisions, including the limited effect given to small features in the 2009 Black Sea (Romania v. Ukraine) case. Türkiye is not a party to UNCLOS and states that it is not bound by provisions it did not accept.
• Equal rights of Turkish Cypriots. According to the Ministry of Foreign Affairs and the TRNC authorities, Turkish Cypriots are co-owners of the island with inherent rights over its offshore resources, grounded in the 1960 partnership structure and the 1960 Treaty of Guarantee. The 21 September 2011 Türkiye–TRNC Continental Shelf Delimitation Agreement and the TRNC's 2011, 2012 and 2019 revenue-sharing proposals are cited as proof of a cooperative approach. Ankara objects to the Greek Cypriot administration's EEZ agreements with Egypt (2003), Lebanon (2007) and Israel (2010) as unilateral acts that disregard both Turkish and Turkish Cypriot rights. See also Fact Check: Was the 1960 Republic of Cyprus Meant to Be a Greek Cypriot State?.
• Registration as transparency, not unilateral boundary-setting. The Presidency and the Ministry of Foreign Affairs present the plan, unveiled on 16 April 2025 and recorded with IOC-UNESCO on 12 June 2025, as the first time Türkiye's position across the Black Sea, Aegean and Mediterranean has been recorded with a UN body. It builds on the 2004 UN notifications and the 18 March 2020 registration of the outer limits of Türkiye's continental shelf. Ankara states that final boundaries still require agreement between the states concerned.
• Rejection of EU competence and maximalist maps. Ankara argues that the EU is not a competent forum for maritime delimitation between states and that 'Union solidarity' cannot substitute for international law. It rejects the so-called Seville Map, a depiction of maritime zones drawn from an academic study at the University of Seville, which it says would confine Türkiye to a narrow strip in the Gulf of Antalya.
• Dialogue remains on the table. President Recep Tayyip Erdoğan's 2020 call for an Eastern Mediterranean Conference including all coastal states and the Turkish Cypriots, together with Türkiye's readiness to negotiate with Greece, is presented as evidence that Ankara seeks inclusive solutions. The Presidential Circular of 24 July 2025, which created an Inter-Agency Coordination Board under the Ministry of Foreign Affairs, institutionalizes the policy domestically.

Türkiye's relevant domestic and diplomatic doctrine is also known as Mavi Vatan (Blue Homeland), the concept of Türkiye's maritime jurisdiction areas in the Black Sea, Aegean and Mediterranean. The climate and environmental dimensions of ocean policy are connected to Ankara's broader agenda, explained in COP31 and Zero Waste.

Source Comparison

The table shows how the main sources frame the same issues. It is a comparison of stated positions, not a ruling on the merits.

Issue	Greek, Greek Cypriot and EU sources	Turkish primary sources	Editorial note
Nature of the registration	Argue a unilateral plan cannot create or confirm rights over areas claimed by others	Describe it as a first recording of Türkiye's position with a UN body and a transparent governance step	IOC-UNESCO records plans; it does not rule on overlapping claims
Effect of islands	Islands, including Kastellorizo, generate full EEZ and shelf under UNCLOS Article 121	Islands near a long mainland coast should not cut off its projection; equity prevails	Courts have varied the effect of small features case by case
Applicable law	UNCLOS reflects customary law that binds all states	Türkiye is not a party and invokes equitable principles under customary law	The status of specific UNCLOS provisions as custom is itself debated
Türkiye–Libya memorandum	EU Council: infringes third-state rights and has no legal effect on them	Valid bilateral delimitation between two coastal states with opposite coasts	Contested in Libya's own politics, which complicates its status
Role of Turkish Cypriots	Resources belong to all Cypriots; revenue-sharing within a settlement	Equal and inherent rights now, grounded in the 1960 order; 2011 agreement with the TRNC	Recognition of the TRNC is limited, which shapes how the 2011 agreement is treated
Forum for resolution	ICJ or arbitration	Bilateral negotiation; an inclusive regional conference	Greece and Türkiye have not agreed on a compromis for third-party adjudication

For wider media-literacy context on how claims about Türkiye are presented and checked, see Region Scope's fact check of common claims in international media. For the editorial method behind this page, see Editorial Principles.

What to watch next

• Whether neighboring states publish or revise their own plans in overlapping areas, and how they depict contested limits.
• Further protests, notes verbales or declarations at the UN referring to the 2025 plan or to the 2019 memorandum.
• Progress in the Greece–Türkiye dialogue and any move toward a compromis for judicial settlement.
• The work of the Inter-Agency Coordination Board and any new marine protected areas or zoning decisions.
• Developments in Libya that affect the continued validity of the 2019 memorandum.

Key Terms & Related Guides

• Marine spatial planning (MSP): a public process to allocate sea areas to uses and protect ecosystems; it organizes, but does not delimit.
• IOC-UNESCO: the Intergovernmental Oceanographic Commission of UNESCO, the UN body for ocean science and a promoter of MSP; it records plans but does not arbitrate boundaries.
• Continental shelf: the seabed and subsoil extending from a coastal state's land territory; rights over its resources exist ipso facto under customary law and UNCLOS.
• Exclusive Economic Zone (EEZ): a zone up to 200 nautical miles in which a coastal state has sovereign rights over living and non-living resources.
• Delimitation: fixing the line between overlapping maritime zones, by agreement or by a court or tribunal.
• Equity principle: the rule that delimitation must produce an equitable result taking account of relevant circumstances such as coastal geography and proportionality.
• Mavi Vatan (Blue Homeland): the Turkish doctrine of maritime jurisdiction in the Black Sea, Aegean and Mediterranean.
• TRNC: the Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983.
• PKK: a group designated as a terrorist organization by Türkiye, the United States, NATO and the European Union; it is mentioned here only because maritime security and counter-terrorism are often discussed together. See WorldPoliticsDaily's explainer.

Related guides on Politepolity:

• Treaties That Define Türkiye: Lausanne, Kars and Montreux
• The 1960 Partnership Republic
• The 2004 Annan Plan Referendum
• Article 51 and the Legal Test for Self-Defense
• About Politepolity and the Politepolity FAQ

For Black Sea diplomacy that intersects with maritime security, see also Crossroads Review on Türkiye's mediation and the Black Sea Grain Initiative.

Perspective Note

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

Politepolity Editorial Team