Home EJIL Analysis Part I: Analysis of Dispute Concerning Delimitation of the Maritime Boundary between Ghana and Côte d’Ivoire in the Atlantic Ocean

Part I: Analysis of Dispute Concerning Delimitation of the Maritime Boundary between Ghana and Côte d’Ivoire in the Atlantic Ocean

Published on October 19, 2017        Author:  and

On 23 September 2017, the Special Chamber of the International Tribunal for the Law of the Sea (ITLOS) rendered an award in Ghana/Côte d’Ivoire. It is only the second case, following the Guyana/Suriname Arbitration of 2007, in which an international adjudicating body has ascertained the meaning and scope of Articles 74(3) and 83(3) of the United Nations Convention on the Law of the Sea (UNCLOS) within the context of unilateral oil and gas operations in disputed areas.

The Special Chamber delimited the parties’ territorial sea, exclusive economic zone (EEZ) and continental shelf boundaries within and beyond 200 nautical miles (nm) with the boundary being an unadjusted equidistance line favouring Ghana. Other key questions for adjudication were a) Ghana’s claim regarding a long-standing, tacit agreement as to the existence of a maritime boundary and b) Côte d’Ivoire’s allegation that, by continuing with oil activities in the disputed area, Ghana had violated its Article 83(1) and (3) UNCLOS obligations to negotiate in good faith and to make every effort through provisional arrangements not to jeopardise or hamper arrival at an agreement.

In its judgment, the Special Chamber reached a number of conclusions which, taken with its Order for the prescription of provisional measures of 25 April 2015, will have significant, practical implications for the future conduct of unilateral oil and gas activities in disputed maritime areas, as well as for the associated rights and obligations incumbent upon States concerned.

This post is divided into two parts: the first part provides a brief background of the case and presents the most notable features of the Special Chamber’s judgment; the second part analyses several issues of general significance which flow from the judgment. 

Historical Background

Ghana and Côte d’Ivoire are adjacent to each other in the Gulf of Guinea on the Atlantic Ocean – a maritime area containing large reserves of hydrocarbons which both States have been eager to exploit. In 2007, the discovery of the major Jubilee oilfield 32nm off the Ghanaian coast attracted significant interest from foreign investors in Ghana’s hydrocarbon potential. Subsequently, in March 2009, the Tweneboa, Enyenra and Ntomme (TEN) fields were discovered only 3nm east of Jubilee. By the time the issue of maritime delimitation was brought into bilateral negotiations between the parties, the TEN and Jubilee oilfields were all under development by a consortium of companies led by London-based Tullow Oil. Côte d’Ivoire objected to Ghana’s ongoing oil activities, asserting that they were being conducted in the Ivorian maritime area. Following this assertion, the parties agreed to establish the ‘Joint Ivorian-Ghanaian Commission on Maritime Border Demarcation’, and maritime delimitation negotiations commenced. On 3 December 2014, after little progress in diplomatic negotiations, Ghana and Côte d’Ivoire agreed to submit the maritime boundary dispute to the Special Chamber of ITLOS. Both States are parties to UNCLOS; the Convention was applicable to their dispute as a matter of treaty law [Judgment, para 91-99].

Provisional Measures Order of 25 April 2015

A subsequent dispute arose regarding Ghana’s oil exploration and exploitation operations. Côte d’Ivoire filed with the Special Chamber a Request for the prescription of provisional measures under Article 290(1) of UNCLOS, asking that Ghana be ordered to suspend immediately all oil activities in the disputed maritime area. Côte d’Ivoire argued that Ghanaian geophysical surveys were infringing its exclusive, sovereign right to conduct marine scientific research, pursuant to Article 246(5) of UNCLOS, and its associated right to access, possess and control all confidential information relating to exploration of the continental shelf. [Request of Côte d’Ivoire, 25 February 2015, para 30] It also argued that the oil activities impeded the implementation of Ivoirian domestic energy policy (constituting infringement of another sovereign right), [Request of Côte d’Ivoire, 25 February 2015, para 38] and that Ghana was violating its Article 83(3) UNCLOS obligation to ‘make every effort to enter into provisional arrangements of a practical nature and … not to jeopardize or hamper the reaching of the final agreement’ on delimitation.

The Special Chamber’s Provisional Measures Order recognised that drilling causes a ‘permanent physical modification’ of the area in dispute, which no financial compensation or reparation could restore. [Order of 25 April 2015, para 89-90] Nonetheless, the Chamber stopped short of ordering the complete shutdown of Ghana’s petroleum exploration and exploitation operations in the disputed area. Instead, it required that Ghana ‘take all necessary steps’ to prevent information resulting from its oil activities to be used to the detriment of Côte d’Ivoire, and that no ‘new drilling’ take place in the disputed area until resolution of the dispute [Order of 25 April, para 108(1)(a)]. Crucially, the Special Chamber did not order the full suspension of exploitation activities in the TEN fields, recognising that the development phase was already underway, and that the abandonment of operations – and consequent deterioration of equipment – risked causing ‘considerable financial loss to Ghana and its concessionaries’, and posed ‘a serious danger to the marine environment’. [Order of 25 April 2015, para 99]  

Judgment of 23 September 2017

Existence of a tacit agreement

The Special Chamber first addressed the substantive legal issues relating to Ghana’s claim that the parties had effected, by tacit agreement, the course of their maritime boundaries in the territorial sea, EEZ and continental shelf within and beyond 200nm. The Special Chamber noted that the parties’ oil activities had been confined to areas lying on their respective sides of a line which ‘was of relevance to both Parties when conducting their oil activities’ [Judgment, para 146]. However, it found that oil practice (being limited to seabed exploration and exploitation within 200nm) and petroleum legislation enacted by the two States were of limited relevance to the process of establishing a common, multi-purpose boundary for the territorial sea, the EEZ, and continental shelf within and beyond 220nm [paras 148-150; 163]. The Special Chamber also noted Côte d’Ivoire’s history of objections to Ghana’s activities in the disputed area, [para 147] and dismissed Ghana’s claim that a tacit agreement existed.

Delimitation of the maritime boundary

The Special Chamber went on to delimit the maritime boundaries between the two States. Both parties were in agreement that the Special Chamber could draw a single boundary, and that the same methodology should be employed for delimitation of all maritime zones. Given the absence of complex, geographical peculiarities (such as small islands) in the delimitation area [para 285], the Special Chamber opted for an equidistance/relevant circumstances-methodology’ – a ‘delimitation methodology which has been practised overwhelmingly by international courts and tribunals in recent decades’ [para 287-289].

In order to draw a provisional equidistance line, the Special Chamber needed to identify the parties’ relevant coasts and the relevant area (i.e. the area over which the projections of the parties’ coasts overlap) and the coastal base points from which to draw the provisional equidistance. It held that the relevant coastlines had no marked concavity or convexity; the provisional line required no adjustment. It considered as irrelevant the location of hydrocarbon resources and previous oil practice [paras 475-479].

For the third and final stage of delimitation, the Special Chamber employed an ex-post facto (dis)proportionality test to verify that the provisional equidistance line did not produce an inequitable result by reason of any marked disproportion between the ratio of respective coastal lengths and the ratio between relevant maritime areas allotted to each party [para 533]. It held that the ratio of relevant areas was Ghana 139km : Côte d’Ivoire 352km (approximately, 1 : 2.53); the ration of allocated maritime areas was approximately 1 : 2.02 in favour of Côte d’Ivoire. The Special Chamber concluded that the equidistance line is the single maritime boundary for the territorial sea, EEZ and continental shelf within and beyond 200nm [para 540]. The established boundary is a strict equidistance favouring Ghana.

International responsibility of Ghana

Lastly, the Special Chamber considered the issue of Ghana’s unilateral activities in the disputed maritime area, and whether such activities engaged its international responsibility [para 541-544].

According to Côte d’Ivoire, Ghana’s hydrocarbon activities in the relevant area constituted a violation of Côte d’Ivoire’s sovereign rights over its continental shelf. Ghana had continued with several drilling operations in the TEN oilfields and, crucially, the TEN fields were located in the maritime area claimed by Côte d’Ivoire. Nevertheless, the Special Chamber considered that, in the case of overlapping continental shelf claims, ‘both States concerned have an entitlement to the relevant continental shelf on the basis of their relevant coasts’, and that ‘only a decision of delimitation establishes which part of the continental shelf appertains to which of the claiming States’ [para 591]. Therefore, it held that hydrocarbon activities undertaken by a State in an area subject to overlapping claims, before the area in question has been delimited by adjudication, does not give rise to international responsibility of that State – even when it turns out that these activities were conducted in an area belonging to the other claiming State [para 589].

The Special Chamber next turned to Côte d’Ivoire’s claim that Ghana’s hydrocarbon activities in the disputed area constituted a violation of the obligations enshrined in Articles 83(1) and 83(3) of UNCLOS [para 609]. The Special Chamber noted the prominence in UNCLOS of Article 83(1) – the obligation to negotiate in good faith [para 604] – but observed that the parties had conducted several diplomatic negotiations on maritime delimitation between 2008 and 2014. Côte d’Ivoire had failed to provide convincing evidence that those negotiations had not been meaningful, and so the Special Chamber rejected its claim relating to Article 83(1).

Turning to the alleged violation of Article 83(3), the Special Chamber explained that that treaty provision contains two interlinking obligations for the States concerned, namely: ‘to make every effort to enter into provisional arrangements of a practical nature’; and, ‘during this transitional period, not to jeopardize or hamper the reaching of the final agreement’. In relation to the first obligation, the Special Chamber noted that Côte d’Ivoire had not requested that Ghana enter into provisional arrangements, but only that it refrain from further oil activities. This prevented Côte d’Ivoire from arguing that Ghana had breached that obligation. With regard to the second obligation, the Special Chamber found that Ghana’s continuation of hydrocarbon activities was not a violation: Ghana had suspended its drilling activities by implementing the Order of 25 April 2015, and it had only undertaken hydrocarbon activities in the area which the Special Chamber found to be within Ghanaian waters. Therefore, none of Ghana’s activities occurred within Ivorian waters, and Côte d’Ivoire’s submission was without foundation [para 633].

The second part of this post will comment on some of the key issues raised in the judgment, particularly the question of State responsibility and the Special Chamber’s treatment of Article 83(1) and (3) of UNCLOS within the context of unilateral petroleum operations in disputed maritime areas.

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2 Responses

  1. […] overview of the Ghana/Côte d’Ivoire judgment is provided in the first part of this post. The purpose of this second part is to highlight issues of practical significance […]

  2. […] overview of the Ghana/Côte d’Ivoire judgment is provided in the first part of this post. The purpose of this second part is to highlight issues of practical significance […]

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