1 Responsibilities and Obligations of States Sponsoring Persons and Entities with Respect to Activities in the Area, Case No. 17, Advisory Opinion (ITLOS Seabed Disputes Chamber Feb. 1,2011), 50 ILM 458 (2011), available at http://www.itlos.org/ [hereinafter Advisory Opinion].

2 Request for Advisory Opinion, in Letter from Nii Allotey Odunton, secretary-general of the International Seabed Authority [ISA], to Tullio Treves, president of the Seabed Disputes Chamber (May 11,2010), at http://www.itlos.org/index.php?id= 109&L=0. The original request was electronic and certified true copies were forwarded by the ISA legal counsel on June 8, 2010, and received by the ITLOS Registry on the same date.

3 United Nations Convention on the Law of the Sea, opened for signature Dec. 10,1982,1833 UNTS 396, available at http://www.un.org/Depts/los/ [hereinafter UNCLOS].

4 Id., Art. 137.

5 Id., Annex III, Art. 8.

6 Agreement Relating to the Implementation of Part XI of the United Nations Convention on the Law of the Sea of 10 December 1982, July 28, 1994, 1836 UNTS 3, available at http://www.un.org/Depts/los/.

7 Bureau of East Asian and Pacific Affairs, U.S. Dep’t of State, Background Note: Nauru (Jan. 26, 2011), at http://www.state.gOv/r/pa/ei/bgn/16447.htm.

8 Bureau of East Asian and Pacific Affairs, U.S. Dep’t of State, Background Note: Tonga (Dec. 23, 2010), at http://www.state.gOv/r/pa/ei/bgn/16092.htm.

9 At the fifteenth annual session of the Authority (May 25-June 5,2009), the Legal and Technical Commission decided to defer further consideration of these applications. Summary Report of the Chairman of the Legal and Technical Commission on the Work of the Commission During the Fifteenth Session, para. 6 UN Doc. ISBA/15/C/5 (May 27, 2009). Documents relating to the ISA’s annual sessions are available online at http://www.isa.org.jm/en/sessions/ and at http://www.un.org/documents/.

10 Nauru, Proposal to Seek an Advisory Opinion from the Seabed Disputes Chamber of the International Tribunal for the Law of the Sea on Matters Regarding Sponsoring State Responsibility and Liability, UN Doc. ISBA/16/C/6 (Mar. 5, 2010).

11 Id, para. 1.

12 Id, para. 5; see UNCLOS, supra note 3, Arts. 148, 150, 152(2).

13 See ISA Council, Decision Requesting an Advisory Opinion Pursuant to Article 191 of the United Nations Convention on the Law of the Sea, UN Doc. ISBA/16/C/13 (May 6, 2010), reprinted in Letter from Nii Allotey Odunton, supra note 2, enclosure. “As indicated by the Authority in its written statement and at the hearing, the decision adopted by the Council on 6 May 2010 was taken ‘without a vote’ and ‘without objection.’“ Advisory Opinion, para. 4 (citing Written Statement of the Authority, para. 2.4, UN Doc. ITLOS/PV.2010/1/Rev. 1 (Aug. 19, 2010), at http://www.itlos.org/index.php?id=109&L=0).

14 Within the time limits, statements were received from Australia, Chile, China, Germany, the Republic of Korea, Mexico, Nauru, the Netherlands, the Philippines, Romania, the Russian Federation, and the United Kingdom, in addition to the Authority, the Interoceanmetal Joint Organization, and the International Union for Conservation of Nature and Natural Resources. Beginning on September 14,2010, oral proceedings were held, giving an opportunity to speak to all those who had sent statements, as well as the UNESCO Intergovernmental Oceanographic Commission.

15 The Chamber declined to comment on whether the difference in wording between the Statute of the International Court of Justice and Article 191 of the 1982 Convention means that, whereas the ICJ has discretion under its statute to render an advisory opinion, this same discretion does not exist for the Chamber. Compare UNCLOS, supra note 3, Art. 191 (stating that the Chamber “shall give” advisory opinions), with Statute of the International Court of Justice, Art. 65(1) (stating that the Court “may give” an advisory opinion).

16 ISA, Regulations for Prospecting and Exploration of Polymetallic Nodules, at http://www.isa.org.jm/en/documents/mcode; ISA, Regulations for Prospecting and Exploration of Polymetallic Sulphides, at id.

17 Discussed further in text at note 27 infra.

18 UNCLOS, supra note 3, Art. 139(1).

19 Id., Art. 153(4).

20 This paragraph, however, continues in a way that severely restricts possible answers to question 2. See note 25 infra and corresponding text.

21 Pulp Mills on the River Uruguay (Arg. v. Uru.), para. 187 (Int’l Ct. Justice Apr. 20, 2010), at http://www.icj-cij.org/. For further discussion on the obligation to ensure, see infra note 30 and corresponding text.

22 Note that the equivocal wording of Principle 15 requires states only to introduce “cost-effective measures” “according to their capabilities.” Rio Declaration on Environment and Development, princ. 15, June 14, 1992, UNDoc.A/CONF.151/5/Rev.l (June 13, 1992) [hereinafter Rio Declaration], reprintedin 31 ILM 874 (1992). This wording was reportedly introduced by the United States at the 1992 Rio Conference.

23 See, e.g., Freestone, David & Hey, Ellen, The Precautionary Principle and International Law: The Challenge of Implementation (1996)Google Scholar; Freestone, David, The Marine Environment, in The Reality of Precaution: Comparing Risk Regulation in The United States and Europe 177 (Wiener, Jonathan B., Rogers, Michael D., Hammitt, James K., & Sand, Peter H. eds., 2011)Google Scholar.

24 ISA, Standard Clauses for Exploration Contract, at http://www.isa.org.jm/en/documents/mcode. For the regulations on sulfides, see supra note 16.

25 UNCLOS, supra note 3, Art. 139(2), & Annex III, Art. 4(4).

26 This reflects great credit on Tullio Treves, president of the Chamber, whose task it would have been to forge consensus.

27 See text at note 17 supra.

28 Article 139(1) is quoted in the text at note 18 supra.

29 See note 21 supra and corresponding text.

30 Indeed, the Chamber quotes Article 194(2) of the Convention as another example of a similar obligation: “States shall take all measures necessary to ensure that activities under their jurisdiction or control are so conducted as not to cause damage by pollution to other States and their environment. . . .” Advisory Opinion, para. 113. Although not cited, this wording is derived from Principle 2 of the Rio Declaration, supra note 22, and Principle 21 of the Stockholm Declaration on the Human Environment, June 16,1972, UN Doc. A/CONF.48/14 & Corr. 1 (June 15, 1972), reprinted in 11 ILM 1416 (1972). It surely supports the fact that this approach represents customary law.