Trans-Tasman Resources has submitted the first marine consent application for seabed mining on New Zealand’s North Island's west coast.

If granted, the consent could generate an extra $147 million in exports for New Zealand and would ultimately involve the excavation of up to 50 Mt/a (55 million stpy) of iron ore. However, news of the application has also got the interest of environmental groups that oppose the process of sea floor mining.

Trans-Tasman Resources (TTR) will submit a bid to mine 65 sq km of exclusive economic zone seabed in the South Taranaki Bight for iron-rich sand particles.

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, the New Zealand Herald reported.

Trans-Tasman Resources said 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.

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.

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."

According to the company, the mining would be done by remote-controlled 12-m- (40-ft-) long, 350-t (385 st) ``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 300 sq mile block by block, but the company believed the areas could soon be repopulated.