Commission on the Limits of the Continental Shelf issues recommendations on Japan’s submission

On 12 November 2008, Japan submitted information on the limits of its continental shelf beyond 200 nautical miles (“nm”) to the Commission on the Limits of the Continental Shelf (“CLCS” or the “Commission”). Nearly four years later, the CLCS has issued its recommendations. The most notable among these is the CLCS’s decision not to take action on Japan’s claim to a continental shelf beyond 200 nm around an atoll in the Philippine Sea that Japan claimed to be an ‘island’. The decision follows statements of formal opposition by the Republic of Korea (“South Korea”) and the People’s Republic of China’s (“China”) to the CLCS’s consideration of this aspect of Japan’s submission, due to the existence of a dispute over the legal status of the atoll. Under the United Nations Convention on the Law of the Sea (“UNCLOS”), rocks which cannot sustain human habitation or economic life of their own are not entitled to an exclusive economic zone (“EEZ”) or, therefore, to an extended continental shelf.

The Continental Shelf and UNCLOS

UNCLOS sets out a regime of maritime zones, in which the internal waters (rivers and lakes) of a State or the archipelagic waters of an archipelagic State such as Indonesia, Japan, and the Philippines, are within the sovereignty of the State. The territorial waters of a State, which reach out to 12 nm from a State’s baselines (the low-water line of a State’s coast), are also within that State’s sovereignty, though are subject to the right of innocent passage of foreign ships. A State’s contiguous zone, in which the State has jurisdiction to enforce, but not to prescribe, extends out beyond the outer limit of the territorial waters up to a further 12 nm. The EEZ of a State covers both the territorial waters and the contiguous zone, and extends a further 176 nm beyond the edge of the contiguous zone, up to a distance of 200 nm from the State’s baselines.

Under Article 76(1) of UNCLOS, every coastal State also has a “continental shelf” that extends to the outer edge of its continental margin or to a distance of 200 nm from the State’s baselines, if the continental margin does not stretch out beyond 200 nm. The continental margin is comprised of the continental shelf (as geomorphologically defined), the continental slope, and the continental rise. According to Article 77(1) of UNCLOS, “the coastal State exercises over the continental shelf sovereign rights for the purpose of exploring it and exploiting its natural resources”. This right is an exclusive right (Article 77(2)), and does not depend upon occupation or express proclamation (Article 77(3)).


Diagram of the maritime zones. The continental shelf is the shallow platform that surrounds the land above the sea; the continental slope is the steep descent from the edge of shelf to the foot of the continental slope. The foot of the continental slope marks the beginning of the continental rise, where the gradient drops into a gentle decline until the beginning of the (relatively flat) deep-sea ocean floor. (Source: UNEP/GRID-Arendal).

The continental shelf of many coastal States holds important and valuable resources, such as oil, gas, methane hydrate (in the Japanese shelf), diamonds (off the Namibian coast), many different types of minerals and precious metals, and fishing stocks of sedentary species such as clams and oysters. Thus the determination of the outer limits of the continental shelves of coastal States has been a priority of the international community for nearly a century.

Submissions to the Commission on the Limits of the Continental Shelf

The calculation of the extent of the continental margin under Article 76(4) and the application of limits to it prescribed by Articles 76(5) and (6) leaves some room for uncertainty and it is for this reason that negotiating parties to UNCLOS decided to establish, under Annex II of UNCLOS, the CLCS. The mandate of the CLCS is to receive information, submitted by coastal States, on the limits of the continental shelf beyond 200 nm from the territorial sea baselines (Article 76(8) of UNCLOS). The CLCS shall then make “recommendations to coastal States” on the limits of their continental shelves. The Commission received its first submission, from the Russian Federation, in 2001. Since 2001, the Commission has received 61 full or partial submissions and made recommendations in respect of 18 of those.

Japan made its (full) submission to the CLCS in November 2008 (Executive Summary available here). Its submission set out seven regions in which Japan claimed an extended continental shelf beyond 200 nm, one of which related to the Southern Kyushu-Palau Ridge Region, in the Philippine Sea. Japan stated that “[t]he continental margin in this region extends to the south along the Kyushu-Palau Ridge, which forms a natural prolongation of Japan’s land mass on the Ridge represented by Oki-no-Tori Shima Island” (page 9 of the Executive Summary). Japan also stated, in accordance with the Commission’s Rules of Procedure, that no aspect of its submission was the subject of any dispute apart from in relation to potential overlaps in the continental shelves between Japan and the USA, and between Japan and the Republic of Palau (pages 7 and 8 of the Executive Summary).

In February 2009 both China and South Korea sent notes verbales containing their comments on the submission to the CLCS. Both notes emphasized that Oki-no-Tori Shima is in fact a rock, not an island. Under Article 121(3) of UNCLOS, “[r]ocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf.” China and South Korea argued that, as a rock, Oki-no-Tori Shima is not entitled to an EEZ or any continental shelf. They added that it is beyond the mandate of the Commission to make any recommendations on the continental shelf within and beyond 200nm measured from the “rock” of Oki-no-Tori, since this would involve the interpretation and application of Article 121. China and South Korea therefore requested that the Commission set aside this aspect of Japan’s submission from its review.

The Commission, at its 23rd Session, acknowledged that it had no role in the legal interpretation of Article 121 of UNCLOS. At the 24th Session, the Commission reiterated that its role is limited to the consideration of submissions relating only to Article 76, and that its recommendations are without prejudice to the interpretation or application of other parts of the Convention. The Commission therefore decided that it “shall not take action… in relation to the area referred to in the notes verbales [of China and South Korea], until the Commission decides to do so.”


The CLCS is an independent scientific and technical body, made up of experts in inter alia geology, geophysics and hydrography who are elected to the CLCS by UNCLOS States Parties. The CLCS does not have judicial powers; its recommendations are not binding per se. However, if a coastal State bases its claim to the limits of its continental shelf on the Commission’s recommendations, they then become “final and binding” for that State and all other UNCLOS States. There is authority for the view that such a claim also becomes binding on other non-UNCLOS States, if no State has objected within a reasonable period of the coastal State’s depositing details of its claim with the UN Secretary-General.

In early April 2012, China and South Korea sent further notes verbales requesting the CLCS not to make any recommendation in relation to Oki-no-Tori, due to the existence of a “dispute concerning Oki-no-Tori Shima’s legal status” (note verbale of South Korea, 5 April 2012). China added that this dispute concerned “whether relevant maritime space is under national jurisdiction or a common space of the international community” (note verbale of China, 5 April 2012). Japan responded that China and South Korea’s arguments had “no legal basis” (note verbale of Japan, 9 April 2012).

On 19 April 2012, the CLCS adopted its recommendations on the Japanese submission (available here).
Though it was not legally bound to do so, the Commission followed the requests of China and South Korea and decided not to take any action in relation to Japan’s submissions on the Southern Kyushu-Palau Ridge Region “until such time as the matters referred to in the notes verbales have been resolved” (page 5 of the Recommendations).


The Commission’s decision is significant in that it presents a potential obstacle to Japan’s ability to claim a sizeable area of continental shelf around the Oki-no-Tori Shima atoll. It also underlines the fact that States cannot circumvent direct resolution of legal disputes by the back-door process of CLCS submissions; after all, the CLCS is not a judicial body. This is undoubtedly the rationale behind Rule 5, Annex I of the Rules of Procedure, which stipulates that “[i]n cases where a land or maritime dispute exists, the Commission shall not consider and qualify a submission by any of the States concerned in the dispute” unless the Commission has the prior consent of all States Parties to such dispute. The CLCS evidently considered the notes verbales received from China and South Korea to provide clear evidence that such a dispute exists and accordingly took no action. China has taken similar diplomatic action aimed at preventing consideration by the CLCS of a number of other outer continental shelf claims by its neighbours in the South China Sea. At the same time, it has made clear its intention to submit to the CLCS its own outer shelf claims in the East China Sea. All eyes are now on how the CLCS will respond in those cases.