A company which spent up to $65 million in a failed bid to mine ironsands from the South Taranaki seabed, has applied for a prospecting permit covering a huge swathe of seabed north of Ross.
The Green Party today called for a moratorium on seabed mining, which it described as "completely experimental".
Trans-Tasman Resources announced yesterday it had applied to the Crown agency New Zealand Petroleum and Minerals for a 4436 square kilometre prospecting permit extending from Ross to north of Karamea, from 1km offshore out to the 12 nautical mile territorial limit.
Trans-Tasman's previous bid to mine in the exclusive economic zone was rejected by the Environmental Protection Agency last year.
The company said in a statement it would focus on developing offshore mineable resources of iron-rich mineral sands known to host ilmenite, zircon, garnets and gold. Ilmenite can be used for paint, and garnets for sandblasting.
"These Westland sands seafloor heavy and precious mineral deposits, in around 20 to 80m of water, will be amenable to conventional seafloor mining technology currently being developed by (Trans-Tasman Resources) for its offshore South Taranaki Bight iron sands project," executive chairman Alan J Eggers said in a statement yesterday.
The company would use its current seafloor drilling technology, exploration, geological, engineering and permitting expertise, developed on its South Taranaki Bight iron sands project, to assess the potential of the Westland sands targets and resources, Mr Eggers said.
But Green Party conservation spokeswoman Eugenie Sage called on the Government to declare a moratorium on seabed mining, as Australia's Northern Territory and Namibia had done.
"It is completely experimental and has the potential for major impacts on the seabed, water quality and marine mammals and other marine life," Ms Sage said.
"A moratorium would avoid the company wasting its resources, and the public having to waste their time mobilising to oppose it to protect our marine environment."
She said there may be a future for seabed mining, but only if it could be proven safe, and only in the context of a comprehensive oceans policy and a good network of effective marine protected areas.
"With the West Coast a stronghold for Hector's dolphin, Trans-Tasman will face similar public opposition here as they did off the North Island's west coast."
Trans-Tasman is headquartered in Wellington and funded by New Zealand and international investment.
In 2011, prospecting company Seafield Resources abandoned its search for gold in the seabed off the West Coast because the gold deposits were buried too deep under the seafloor.