Stake in the sand

International concern about seabed mining is growing, as the battle continues over whether to allow it in New Zealand.

- RICHARD WOODD

Tens of thousands of years ago, violent volcanic eruptions thrust billions of tonnes of black iron sand into what is now called the South Taranaki Bight. The ironsand settled on the seabed, covering an area estimated at 36,000 sq km.

Today, another flurry of intense activity is under way – but this time it is billions of dollars that will potentially be deposited in the ocean. Three massive projects to extract valuable resources from the area have been proposed. The co-owners of the Kupe oil field, Beach Energy and Genesis Energy, are seeking marine consents to drill two more wells. The NZ Super Fund is considering investing $5 billion in a huge offshore wind farm (see page 23). And a company called Trans-Tasman Resources (TTR) is still hoping to spend at least $1 billion mining part of the seabed for particles of iron ore, titanium and vanadium.

Of the three projects, it is the latter one that has so far proved the most explosive.

TTR wants to use a robot crawler machine to systematically vacuum the seabed. The sand would be sucked up into a nearby processing vessel, which would use magnets to extract the iron ore and other metals and send the remaining 90% of sand back where it came from. The ore would then be loaded onto bulk carriers and exported to steel factories in China.

The company wants to take up to five million tonnes of ore a year for 20 years from an area more than 20km offshore, covering 66 sq km in our Exclusive Economic Zone, in depths of at least 20m. But nine years after it first applied for consents, it has yet to start work. After winning initial permission from the Environmental Protection Authority in 2017, TTR has since met rejection at the High Court, the Court of Appeal, and last year, the Supreme Court.