The first marine consent application for seabed mining on the North Island's west coast is about to be lodged, rallying environmental groups over what one described as the most important clash on the issue.
Trans-Tasman Resources says it will this week lodge a bid to mine 65sq km of exclusive economic zone seabed in the South Taranaki Bight for iron-rich sand particles.
But a band of groups including Forest and Bird and Greenpeace called for a moratorium on all seabed mining in New Zealand.
The groups claim there is a lack of knowledge about the marine environments involved and the cumulative effects of mining, an inadequate regulatory process and doubts over the social and economic effects of the operations, as well as the method used.
But the company says its operation would have minimal environmental effects on the surrounding area, and scientific reports were prepared before its application to the Environmental Protection Authority.
Kiwis Against Seabed Mining, which is preparing for a fight, sees the bid as crucial as it believes many more application for mining along the west coast will be lodged if the consent is granted.
"It starts the ball rolling ... it's like the big toe of a giant prying the door open," chairman Phil McCabe said.
His group believed there was still not enough information about the effects on marine life, particularly mammals, and considered the submission period - usually 20 working days then 40 more until hearings began - far too brief.
The proposal has run into opposition along the coast, although TTR resources environment and approvals manager Andy Sommerville said there had been considerable consultation with the community.
Mr Sommerville said the company had looked at other possible effects from the mining, such as on waves, surf breaks, fishing and marine life, but expected it to have little impact.
"We've done a tremendous amount on determining what is out there."
* Trans-Tasman Resources is seeking a consent to mine 65sq km of exclusive economic zone seabed in the South Taranaki Bight for iron-rich sand particles.
* The mining would be done by remote-controlled 12m-long, 350-tonne ``crawler'' machines, which would travel along the seafloor pumping sand to a processing ship above.
* Once iron ore particles were separated magnetically, the sand would be deposited on areas already worked over.
* Any life on the seafloor, such as tubeworms, would be killed as the mining progressed 300sq m block by block, but the company believed the areas would soon be repopulated.
* The project, which seeks to generate an extra $147 million in exports for NZ, would ultimately involve the excavation of up to 50 million tonnes a year.