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New Zealand's Exclusive Economic Zone (EEZ) is the area of sea and seabed that extends from 12 nautical miles off our coast to 200 nautical miles [Seaward of the outer limits of the territorial sea, including the contiguous zone, to an outer limit of 200 NM from the baselines (breadth of the EEZ is normally 188 NM).] as illustrated in Figure 1. Under international law we have 'sovereign rights' over this area (as discussed in the next section). New Zealand has the fifth largest EEZ (roughly 430 million hectares) in the world, about 15 times the size of our land mass. This is because of our distance from other countries, which means that there are only a few areas where the 200nm boundary of another country intersects with ours.

Figure 1: Map of New Zealand's Exclusive Economic Zone (EEZ) courtesy of the Institute of Geological and Nuclear Sciences

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New Zealand's marine ecosystems and species are highly diverse. This is due to a combination of factors, including our geological history and isolation, the range and complexity of habitats, and the influence of major ocean currents. The result is a wide variety, if patchy distribution, of marine plants and animals.

Habitats in the EEZ include plains of mud; volcanic vents such as those near White Island, whose micro-organisms 'breathe' sulphur rather then oxygen; and the great coral-festooned sea mounts of the deep ocean. New Zealand is visited by a number of migratory species, and provides habitats that are critical to the long-term viability of some of these species, particularly marine birds that breed in New Zealand.

Marine scientists estimate that perhaps as much as 80% of New Zealand's indigenous biodiversity is found in the sea. While many of our marine fish also occur in other countries' seas, many of our benthic (bottom-dwelling) marine species are found only in New Zealand waters. Evaluating the state of New Zealand's marine biodiversity is difficult due to the very limited information we have about deep-sea species.

New Zealand's EEZ also provides us with considerable economic opportunities. Fishing (including aquaculture) is New Zealand's fourth largest export earner. However, despite the size of New Zealand's EEZ, its waters are relatively deep (New Zealand's offshore fisheries are among the deepest in the world) and not particularly rich in nutrients, so the productivity of our fisheries resources is relatively low.

Oil and gas have been discovered in several parts of New Zealand's offshore territory, although the only commercial production has been the development of the Maui field, extending 35 to 50 km off the Taranaki coast. The government's recent decision to prioritise and create incentives for gas exploration (due to the decline in the Maui field) has stimulated petroleum exploration activities in the EEZ. A number of offshore oil and gas fields in the EEZ are being appraised and are expected to be developed over the next few years.

New Zealand's EEZ also connects us to the rest of the world, with undersea telecommunication cables, ships and aircraft passing through the zone. Almost 85% of New Zealand exports by value (99% by volume) are carried by sea, [Imports account for 75% by value (also 99% by volume).] and around 90% of international telecommunication services with New Zealand are carried on submarine cable systems (the remainder are carried via satellites). Consequently, a submarine cable failure could have a serious impact on the New Zealand economy.

The oceans offer great potential for innovation and investment in a range of different wealth-creating activities. While a large amount of New Zealand's land-based and fisheries resources are already being utilised, the EEZ and continental shelf offer significant untapped space and resources for future developments.

Despite the importance of our EEZ, regulations to protect the environment in the EEZ are few, inconsistently applied, and variable. Jurisdiction under the Resource Management Act 1991 (RMA), New Zealand's primary environmental management legislation, only extends 12 nautical miles offshore. Some activities in the EEZ, such as the dumping of wastes, are subject to environmental controls but for other activities, such as the laying of pipelines and cables, there are few requirements to consider the environmental effects of the activity.

The Ministry for the Environment has written this report to:

  • outline the context and history of issues relating to environmental management in New Zealand's EEZ, including the current level of activity
  • summarise the current legislative framework for environmental management in the EEZ and expose the management gaps
  • describe the way that other countries manage the environmental effects of activities in their EEZs
  • analyse options for improving environmental management in the EEZ, including any associated issues.