Source: Australian Associated Press

A mining company is appealing the Environmental Protection Agency's decision to reject its application to mine ironsands from the seabed off the Taranaki coast.

The EPA's decision-making committee rejected Trans-Tasman Resources' application on June 18, which was seen as a victory for conservation efforts but a blow to the government's desire to help mineral extraction projects boost the economy.

Trans-Tasman's board announced on Tuesday it will appeal the decision to decline marine consents for mining ironsands in the South Taranaki Bight.

"We have now studied the decision in detail with the assistance of our advisors and experts, and are confident that there are strong grounds for a successful appeal," said the company's chief executive Tim Crossley.

Mr Crossley said he would not comment further on its efforts to gain access to the South Taranaki Bight now that an appeal was being lodged.

TTR had 15 working days from the EPA's rejection to lodge an appeal, and it's expected that a court will deal with the matter within six months.

The miner said its objective is "to develop an ironsands extraction project which achieves substantial economic development while protecting the environment".

The company has spent some $60 million over seven years developing the mineral extraction export proposal.

TTR said it believed it could pull it off in an environmentally sustainable way while creating additional exports of around $150m a year from the sale of around five million tonnes of titano-magnetite iron ore to Asian steelmills.

TTR had planned to use a suction dredging process some 36km off the coast of Patea that it said would have returned 90 per cent of the sands to the ocean floor.

Mining the seabed would have created hundreds of jobs and grown the Taranaki regional economy by $240m a year, TTR said.