John Roughan: Our undersea continent needs better law

When geologists look at New Zealand they don't see the ocean, they see a great lump of granite, one-third the size of Australia, stretching from New Caledonia to our sub-Antarctic islands. The dry land of New Zealand is just its highest plateau.

They say the continent beneath the sea is much like the land we can see. It has mountains and valleys, uplands and plains, high ridges, deep basins. At it highest points it is less than 300m below the surface and falls to 1000 or more metres deep in its troughs. But at its deepest it is barely half the depth of the true ocean floor beyond the continental slope.

The continent is ours. It lies within New Zealand's exclusive economic zone recognised by the United Nations Convention on the Law of the Sea.

One of its highest regions is the Chatham Rise, a long wide ridge lying east of Banks Peninsula and extending beyond the Chathams. In a sense it is our East Island, two-thirds the size of the South Island.

Last week a decision-making committee of the Environmental Protection Agency turned down an application to mine phosphate rock known to be on the Chatham Rise. The venture would merely and literally scrape the surface of the rock for phosphate nodules but the EPA decided it would do significant permanent damage to seabed life, particularly the ecosystems of protected stony corals that were "potentially unique".

They are bound to be unique, every area of seabed has slightly different topography and currents and every area will contain mudlife adapted to its particular position. If biodiversity means all have to be preserved, there will be very little mineral wealth New Zealand can extract from its vast territory.

The Chatham Rise is a valuable fishery. It presents a barrier to subtropical currents from the north and the cold, nutrient-rich southern currents. Their convergence creates good feeding grounds for fish and marine mammals, including the whales that cavort off the Kaikoura coast.

But it is a big ocean. Chatham Rock Phosphate Ltd sought permission to mine little more than 1 per cent of the 100,000 sq km Chatham Rise landmass over 35 years.

Announcing its decision, the EPA said despite the company's efforts to research the environmental effects the decision-making committee was left with "a lack of certainty" about them and about the possible damage to the fishery. Lacking certainty, it said, it was required by its legislation to favour caution and environmental protection.

Its legislation is the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act, drafted and passed under the present Government just three years ago. It is the prototype for the big changes the Government wants to make to the Resource Management Act that governs all consents on dry land.

The EEZ Act requires consideration to be given to economic development along with a raft of ecological protections. It does indeed mandate the precautionary principle if the EPA finds the information available to be uncertain or inadequate. But it also states that if favouring caution means an activity is likely to be refused an "adaptive management approach" must be considered.

In layman's terms, give the venture a chance and check whether it does the damage feared. But that assumes the fears are fairly specific, not precautionary conjecture.

This case is not the first or the worst. Last year a committee refused permission for Trans-Tasman Resources to dredge iron sand in the South Taranaki Bight without so much as a stony coral at risk. Following that rejection, Trans-Tasman Resources filed an appeal to the High Court against the EPA's interpretation of the act but has since withdrawn it, which suggests the courts support the agency's reading. Either that or the company got word that the Government is going to change its act.

The environmental community is clearly fearful the Government will do exactly that. The EPA's press announcement on Chatham Rock Phosphate noted that it has not turned down all three applications it has received under the EEZ Act. It had allowed continued drilling for gas in the Maari field off Taranaki.

The Environmental Defence Society greeted the Chatham Rock decision with a word of sympathy for applicants. "It is a big ask to expect an applicant for a single project to provide all the baseline information required in the absence of any strategic planning guidance about what kind of activities are acceptable and where."

Green MP Gareth Hughes anxiously noted Environment Minister Nick Smith "did not rule out changes to the act to suit the seabed mining industry" when an unrelated amendment went through Parliament this week.

But it is hard to see how the law can be made reasonable if decision makers, supported by the courts, are determined to read it the way they wish.