## Facts

- Australia, New Zealand, and Japan were parties to UNCLOS and the 1993 Convention for the Conservation of Southern Bluefin Tuna (SBT Convention).
- The dispute concerned conservation and management of southern bluefin tuna, a highly migratory species subject to cooperation duties under UNCLOS.
- The SBT Convention created a commission-based regime, including a total allowable catch and national quota allocations.
- Japan initiated a unilateral experimental fishing program (1998–1999) involving catches beyond the agreed total allowable catch after proposals for increased catch were not accepted.
- Australia and New Zealand commenced Annex VII arbitration under UNCLOS in July 1999, alleging Japan breached duties to cooperate and conserve under UNCLOS arts. 64 and 116–119 and related obligations under the SBT Convention.
- Pending the tribunal’s constitution, ITLOS ordered provisional measures in August 1999 directing continued cooperation and restraint to avoid aggravating the dispute.
- Japan raised preliminary objections that the dispute was governed by the SBT Convention’s dispute-settlement provisions, which displaced UNCLOS Part XV procedures.

## Issues

1. Whether an Annex VII tribunal had jurisdiction under UNCLOS Part XV over claims concerning tuna conservation when the parties were also bound by the SBT Convention’s dispute-settlement procedures.
2. Whether the “real dispute” arose under UNCLOS, the SBT Convention, or both.
3. Whether the SBT Convention, as a later and more specific agreement, excluded compulsory dispute settlement under UNCLOS Part XV for this subject matter.
4. Whether the claims were inadmissible for failure to proceed exclusively through the SBT Convention’s dispute-settlement and procedural preconditions.

## Decision

- The tribunal found the controversy was a single dispute arising under both UNCLOS and the SBT Convention because the treaties imposed parallel substantive conservation and cooperation obligations.
- The tribunal held, however, that the SBT Convention’s dispute-settlement regime was intended to be exclusive between the parties for this dispute and therefore displaced recourse to UNCLOS Part XV compulsory procedures.
- The tribunal concluded it lacked jurisdiction to decide the merits and dismissed the claims; it did not determine whether Japan’s experimental fishing violated either treaty.
- The tribunal rejected an argument that ITLOS’s provisional-measures order mooted the case because interim measures did not resolve the underlying dispute.

## Legal Principles

- In assessing jurisdiction, a tribunal examines whether the claims reasonably relate to, and can be evaluated against, the legal standards of the treaty provisions invoked.
- A later, more specific implementing agreement between the same parties may prevail in limited respects over a framework treaty as between those parties, including by displacing the framework treaty’s compulsory dispute-settlement route, consistent with rules governing successive treaties and compatible agreements.
- Parallel substantive obligations in two treaties do not necessarily mean parallel access to compulsory procedures; exclusivity may be inferred from the structure and intent of the specialized treaty’s dispute-settlement design.
- Provisional measures address interim risk and party conduct but do not finally resolve the underlying dispute for purposes of mootness.

## Conclusion

The tribunal treated the conservation dispute as arising under both UNCLOS and the SBT Convention, but held that the SBT Convention’s specialized dispute-settlement process implicitly excluded UNCLOS Part XV compulsory jurisdiction for the parties’ dispute, leading to dismissal without a merits ruling.


Southern Bluefin Tuna (Austl. & N.Z. v. Japan), 39 I.L.M. 1359 (Annex VII Arb. Trib. 2000)