Under international law, a State has exclusive rights over the non-living resources (e.g. petroleum and minerals) and sedimentary species (e.g. oysters and sponges) of the seabed that comprises the underwater extension of its landmass (known as the “continental shelf”). These rights exist by virtue of the State’s sovereignty over its land territory. However, a proportion of the revenue from resources of the continental shelf outside the 200 nautical mile EEZ (up to a maximum of 7%) must be paid to the International Seabed Authority for distribution to developing States. States do not have any special rights to the water column above the continental shelf; so New Zealand does not have special rights to the fisheries above the continental shelf beyond the EEZ or to control other activities such as shipping.
Article 76 of UNCLOS provides a process by which a State can define the geographical outer limits of its continental shelf where they extend beyond the EEZ. States are required to submit information on the outer limits of the continental shelf beyond 200 nautical miles to the United Nations Commission for the Limits of the Continental Shelf (CLCS). The CLCS may make recommendations to the coastal State, and the coastal State shall then define the outer limits of its continental shelf on the basis of those recommendations. Once the outer limits have been established they are “final and binding” on other States.
New Zealand was only the fifth country to present its submission to the CLCS, which it did on 19 April 2006. The New Zealand submission was the result of a ten year $44 million inter-agency project, involving MFAT, Land Information New Zealand, NIWA and GNS Science.
The CLCS issued its recommendations on New Zealand’s extended continental shelf in September 2008. The recommendations confirm New Zealand’s rights over approximately 1.7 million square kilometers of seabed outside the existing EEZ. New Zealand will now set its continental shelf boundary based on the Commission’s recommendations. The boundary will be binding on other countries.
In several areas New Zealand’s continental shelf overlaps with the continental shelves of Australia, Fiji, Tonga and potentially France, so it is necessary for New Zealand to agree on maritime boundaries with these countries. UNCLOS provides that maritime boundaries must be settled by agreement between the States concerned “on the basis of international law…in order to achieve an equitable solution”. An equitable solution is often achieved by drawing the boundary halfway between the two countries, adjusted as necessary to take account of factors such as offshore islands or the respective lengths of the two countries’ coastlines.
New Zealand and Australia agreed a treaty defining a maritime boundary over their overlapping areas of EEZ and continental shelf on 25 July 2004. The boundary has two parts:
New Zealand has also begun preliminary discussions with Fiji and Tonga with respect to the area of overlapping continental shelf along the Colville and Kermadec Ridge complex that extends from the north of the North Island to Fiji and Tonga.