KEY POINTS:
One of the world's largest mining companies has begun an airborne survey of 1200sq km of mineral-rich ironsand deposits along the west coast of the North Island.
The Rio Tinto company is managing the hunt for iron and other metals in a joint-venture with Iron Ore New Zealand, which won the prospecting permit from the Crown Minerals Group in the Ministry of Energy.
As the survey aircraft yesterday flew low and slow over the permit area - at Mokau, north Taranaki and the west coast of south Auckland - iwi and environmental groups and the Auckland Regional Council scrambled for more information about the venture.
Fears were expressed for the impact of any dredging on the maui's dolphin, a species considered critically endangered, found only off the west coast from Northland to New Plymouth.
Ngati Te Ata environment manager Karl Flavell said he had scant information about the prospecting.
"We have not been consulted although we are the tribal authority for the area from Manukau Heads to Maioro, the north side of Port Waikato Heads."
ARC environment chairman Dianne Glenn said she raised three chief concerns about the prospecting at this week's council meeting. "As a result the ARC will write to the Government's conservation, economic development and fisheries ministers.
"One of our concerns is that the maui's dolphin has a particularly strong presence in the permit area - the Waikato River mouth to Manukau Harbour.
"We are also concerned at extra erosion of the coast if there is extraction of sand."
Mrs Glenn said another concern was any mining interference with the build up of the Auckland construction industry's future sand supplies in the Kaipara Harbour. A further concern was the effect of sand extraction on Franklin's surf beaches - Sunset Beach, at Port Waikato and Karioitahi.
Kiwis Against Sand Mining spokesman (Kasm) Bill McNatty said he felt the Rio Tinto joint venture was more "ominous" than previous seabed prospecting bids on the west coast because of the powerful company's environmental record in its operations internationally.
Kasm raised 15,000 signatures for a petition calling for a blanket ban on ironsand mining of the seabed. The petition was presented to Parliament in February and is being considered by the Local Government and Environment Committee.
Mr McNatty said Kasm had sought information from Rio Tinto and it would make strong representations to Crown Minerals if the prospecting advanced to the next stage - applying for an exploration permit.
ARC coastal project leader Andrew Benson said the site within the Auckland Coastal Marine Area was about 480sq km, extending from the northern side of the Waikato River mouth along the Awhitu Peninsula to the South Head of Manukau Harbour.
The landward boundary of the prospecting area was the line of mean high-water mark. The offshore boundary was a line more or less parallel to the Awhitu Peninsula, 15km off shore.
Mr Benson said that the Auckland Regional Coastal Plan allowed prospecting that involved the taking of a small quantity of material, subject to conditions.
Coastal permits - a resource consent allowing prospecting activity - had not been sought.
However, the company advised they might take physical samples early next year and would then assess their need for coastal permits to provide for prospecting.
A spokeswoman for Rio Tinto Iron ore, Joanna McKenzie, said last night from Perth that the aircraft was conducting aeromagnetic surveys over sites in the permit area.
The company owns Comalco, which has the aluminium smelter at Bluff, in the South Island.
The survey conducted by Auckland-based Kiwi Air and Perth-based UTS Geophysics will take a fortnight and the survey plane will fly at a minimum of 20m above the sea and follows grid lines 200m apart.
