China’s Claims to an Extended Continental Shelf in the East China Sea: Meaning and Implications

Publication: China Brief Volume: 9 Issue: 14

On May 11, 2009, the People’s Republic of China (PRC) submitted the preliminary survey findings on the outer limits of its continental shelf to the UN Commission on the Limits of the Continental Shelf (CLCS). The submission makes a claim to an extended continental shelf beyond 200 nautical miles (nm) in the East China Sea (ECS). The submission is reportedly based on data collected over ten years of marine scientific research undertaken by a wide variety of Chinese organizations including the Academy of Sciences, the Hydrographic Department as well as the People’s Liberation Army Navy (PLAN) [1]. That this research program has been undertaken in waters claimed by both China and Japan has been the source of considerable discord. The Chinese submission is preliminary, submitted two days before the May 13 deadline for those states that ratified UNCLOS in 1996. In its submission China claims an extended continental shelf beyond 200nm as far as the western slope of the Okinawa Trough. China states its intention to make a complete submission after further survey work has been completed. This may not be the last extended continental shelf claim made by China, as according to Foreign Ministry spokesman Ma Zhaoxu, it also reserves the right to make additional extended continental shelf claims in the East China Sea and elsewhere [2]. Finally, and consistent with all Chinese territorial claims, the submission states that China will “through peaceful negotiation, delimit the continental shelf with States with opposite or adjacent coasts by agreement on the basis of the international law and the equitable principle” [3].

The East China Sea dispute stems from overlapping jurisdictional claims under the U.N. Convention on the Law of the Sea (UNCLOS). Japan claims an exclusive economic zone (EEZ) as far as its median line that bisects the East China Sea. China, meanwhile, has always claimed a continental shelf as far as the Okinawa Trough based on the principle of natural prolongation, the basis upon which continental shelf claims are made. Political tensions have manifested themselves in a number of ways. The dispute has been exploited by nationalist and conservative actors on both sides to reinforce confrontational policy pursuits. The most serious tensions have occurred at sea where Chinese and Japanese authorities have collided (in some cases quite literally) over resource exploitation and marine scientific research. In June 2008, the two sides agreed on a roadmap toward joint resource development, but no progress has since been made [4]. These disputes stem from competing jurisdictional entitlements to the East China Sea, and thus a ruling by an impartial third party such as the CLCS could move the dispute toward settlement.

What does this submission mean for the East China Sea dispute? There are two primary implications. First, although the submission is made to an impartial third party, this body has no authority to rule on the final delimitation of the East China Sea. The CLCS is not tasked with dispute resolution; it is responsible for evaluating the scientific merits of a state’s claim to a continental shelf beyond the 200nm as permitted under Article 76 of UNCLOS. Thus, at most, the CLCS could rule that the PRC has demonstrated the scientific basis for a continental shelf claim beyond 200nm in the area included in the submission. This is not the same as granting China exclusive jurisdiction over the area it has claimed. Japan is still entitled to claim an EEZ as far as 200nm, although it has only claimed an EEZ as far its median line. Final delimitation is still to be negotiated between the two parties.

This is not to say that a ruling by the CLCS can be expected anytime soon. While the length of time it takes to rule on a submission varies depending on the complexity of the science involved, there are two reasons to expect a significant delay. First, the CLCS is understaffed and under funded [5]. UNCLOS remains a relatively new piece of international law and the entitlement to an extended continental shelf is at the cutting edge of international legal debates. Secondly, due to the ten year deadline for submissions to the CLCS after a state’s ratification of UNCLOS, combined with the enormous amount of ratifications in the mid-late 1990s, the CLCS is confronted with a massive backlog of submissions.  Prior to 2008 the CLCS had received only nine submissions, which took an average of over twenty months to be adopted. Since 2008 the Commission has received 41 submissions and has yet to make a ruling on one of these [6]. Thus it will be quite some time before a Chinese submission can be heard, much less finalized.

The second implication for the East China Sea dispute is the location of China’s extended continental shelf claim; it is located primarily in the northern portion of the East China Sea. As maritime policy analyst Mark Valencia notes, it is unlikely that final delimitation will be based on the recognition of natural prolongation over the EEZ regime, as both are permitted under UNCLOS. It would be more likely that the line reflects compromise over both states’ jurisdictional entitlements [7]. Recognition of the Chinese continental shelf claim by the CLCS adds weight to the Chinese entitlement to a greater share of the ECS, which could arguably push a final delimitation line east toward the Japanese coast. Yet, any CLCS ruling will not touch on the disputed sovereignty over the Senkaku/Diaoyu islands—the basis of the delimitation dispute in the southern end of the ECS—as this is outside its authority. A further problem relates to the northern portion: China’s submission may overlap with the extended continental shelf claimed by the Republic of Korea [8].

To further strengthen its claims to the East China Sea, China has made a rhetorical commitment to the equitable principle in the delimitation of maritime boundaries. This principle relates to special consideration given to coastal states based on social, economic, geological, and geographical factors that impact a state’s entitlement to ocean space. In the Gulf of Maine case, for instance, the International Court of Justice pushed the final boundary line toward Nova Scotia to account for the longer coastline on the American side. In light of the length of the Chinese coastline compared to the Japanese, an extended continental shelf approved by the CLCS further strengthens the Chinese claim to special considerations that ultimately may result in a more favorable settlement. So, a CLCS ruling on China’s entitlement to a continental shelf beyond 200nm—even if it occurs in the near future—does not automatically move the ECS dispute toward resolution. It may however strengthen China’s claims to a larger portion of the northern part of the East China Sea.

The danger in the short term is that the submission and subsequent ruling may escalate tensions in the absence of attempts to clarify the implications for jurisdictional entitlements. Chinese vessels already behave as if the East China Sea and South China Sea are Chinese territorial waters. Witness for example the confrontation with the USNS Impeccable in March 2009 (see China Brief, " Impeccable Affair and Renewed Rivalry in the South China Sea," April 30) and the recurrent Chinese naval intrusions into Japanese-claimed waters. In light of the highly decentralized Chinese command structure (the Impeccable was confronted by a wide variety of vessels in an apparent policing action, including civilian fishing trawlers) it is possible that the submission could reinforce Chinese authorities’ and civilians’ sense of entitlement to the waters off of China. This in turn could increase the latitude with which Chinese vessels operate in Japanese claimed waters. Early signs are that Chinese authorities—fisheries, coastal patrol, and military—will increase their presence in waters that China purports to administer [9]. This comes as Chinese foreign ministry officials and media have condemned submissions to the U.N. by Malaysia, Vietnam and the Philippines for recognition of their maritime borders in the South China Sea. Taken as a whole these trends point to continued Chinese assertiveness in its claimed waters.

This greater naval presence and operational latitude come at a time when Japan is seeking to better protect and exploit its ocean territory. In response to the growing Chinese naval presence in the East China Sea, pressure has been building on Japanese leaders to better enforce Japan’s maritime jurisdiction [10]. In light of Japanese concerns about the longer term strategic consequences of Chinese behavior in waters claimed by Japan, Tokyo would view an increasingly assertive Chinese posture in the East China Sea as a threat [11]. In 2007, Tokyo took the first steps toward rectifying this situation by passing the Basic Ocean Law which created an Ocean Policy Headquarters headed by the prime minister. Furthermore, the first piece of legislation passed on maritime affairs permits Japanese authorities to protect Japanese resource production installations in the East China Sea. This was intended to assuage concerns that Teikoku Oil workers and assets would be threatened by China if they were ever called upon to conduct exploratory drilling east of the median line. Indeed, last year the Diet began considering a law that would allow Japan to intercept suspicious vessels transiting its claimed waters [12]. While this is likely a legacy of Japan’s experience with North Korean espionage boats, it could just as easily provide the basis for an assertive Japanese response to non-authorised Chinese vessels. Recall that in addition to increased reports of Chinese naval incursions in the ECS in recent years, a Han submarine transited Japan’s territorial sea in 2004 and Chinese naval vessels routinely sail provocatively through the international straits that pass through Japan.

The two sides have yet to move forward in implementing the treaty called for by the June Consensus reached in 2008. This means proceeding with plans for Teikoku Oil to conduct joint operations at the Chunxiao gas field with the China National Offshore Oil Corporation (CNOOC) and commencing exploration in the joint development zone south of the Longjing field. The primary barrier to the finalization of a treaty appears to be political. Japanese media reports that Tokyo is reluctant to proceed as long as the development of the Tianwaitian field continues [13]. China maintains that Tianwaitian was not included in the June Consensus, and thus CNOOC’s continued production at the field should not disrupt joint development [14].

While China’s submission to the CLCS does strengthen its claim to the East China Sea, it does little to bring the dispute to a cooperative end. As noted above, it could very well exacerbate tensions in the area. Considerable political will is needed in both Beijing and Tokyo to ensure the continued stability that has characterized the East China Sea for past two years.


1. It is difficult to ascertain which Chinese bureaucratic entity conducts which aspect of the research program. For a discussion see James Manicom, Cooperation and Confrontation in the East China Sea Dispute: Lessons for China-Japan Relations (PhD thesis, Flinders University 2009), chapter five.
2. Foreign Ministry Spokesperson Ma Zhaoxu’s Remarks on China’s Submission of Preliminary Information Indicative of the Outer Limits of the Continental Shelf Beyond 200 Nautical Miles,, May 13, 2009.
3. Preliminary Information Indicative of the Outer Limits of the Continental Shelf Beyond 200 Nautical Miles of the People’s Republic of China, English translation, 2009.
4. Reinhard Drifte, "Territorial Conflicts in the East China Sea – From Missed Opportunities to Negotiation Stalemate," The Asia-Pacific Journal, vol 22-3-09, June 1, 2009.
5. Clive Schofield and I Made Andi Arsana, “Beyond the Limits?: Outer Continental Shelf Opportunities and Challenges in East and Southeast Asia,” Contemporary Southeast Asia, vol. 31, no. 1 (2009): 37-38.
6. Submissions to the Commission on the Limits of the Continental Shelf,
7. Mark J. Valencia, "The East China Sea Dispute: Context, Claims, Issues, and Possible Solutions." Asian Perspective 31, no. 1 (2007): 158
8. Yoo Jee-ho, “Korea submits proposal to extend outer continental shelf,” Joon Gang Daily, May 13, 2009.
9. Zhang Xin, “Change tack with sea strategy: China experts,” China Daily, May 13, 2009.
10. Masahiro Akiyama, "Use of Seas and Management of Ocean Space: Analysis of the Policy Making Process for Creating the Basic Ocean Law." Ocean Policy Studies, no. 5 (2007): 1-28.
11. See for example the annual assessment of Japan’s security environment in Japan’s Defense white papers.
12.  “Japan to Establish Law Aimed at Cracking Down on Suspicious Ships,” Kyodo News, February 26, 2008.
13.  “We Have Right to Exploit Disputed Gas Field: China,” The Japan Times, March 8 2009.
14.  “China Urges Japan not to Distort Consensus on East China Sea Issue,” Xinhua News, January 6, 2009.