The International Tribunal for the Law of the Sea (ITLOS) is a 21-member independent judicial body with the role of adjudicating disputes between States arising out of the interpretation and application of the UN Convention on the Law of the Sea (UNCLOS). It is one of four possible means open to parties to UNCLOS to settle their disputes. Unless the parties to the dispute agree otherwise, ITLOS has mandatory jurisdiction over cases relating to the prompt release of vessels and crews or when a party seeks provisional measures pending the full hearing of a case. In addition, States may designate ITLOS as their preferred venue for the settlement of other types of disputes under UNCLOS. ITLOS has a specially appointed Seabed Disputes Chamber, which deals with disputes concerning the international seabed area, as well as a Chamber of Summary Procedure, a Chamber for Fisheries Disputes, and a Chamber for Marine Environment Disputes.
New Zealand, together with Australia, sought provisional measures from ITLOS in the Southern Bluefin Tuna case in 1999. The case arose from Japan’s announcement that it intended to carry out a unilateral “experimental fishing programme” (EFP) for southern bluefin tuna in mid-1999 in addition to its existing commercial catch. New Zealand and Australia objected to such an EFP outside the framework of the Commission for the Conservation of Southern Bluefin Tuna and in addition to existing catch levels. They submitted the dispute to arbitration under Annex VII of UNCLOS and, pending the establishment of a special Arbitral Tribunal, filed a request for provisional measures with ITLOS in order to stop Japan carrying out its EFP. In August 1999, ITLOS found in favour of New Zealand and Australia and issued provisional measures ordering Japan not to conduct an EFP in addition to its existing commercial catch. In August 2000 the Arbitral Tribunal ruled that it did not have jurisdiction to hear the merits of the case, and the dispute was subsequently resolved by negotiations amongst the three parties.