The company who had its bid to mine iron sands off the coast of South Taranaki overturned by the High Court has turned to the Court of Appeal.
Trans Tasman Resources (TTR) was granted permission to mine by the Environmental Protection Authority (EPA) in August last year, but it was revoked last month by the High Court.
The Judge said the EPA's decision was inconsistent with the law.
He sent the decision back to the EPA "for reconsideration, applying the correct legal test in relation to the concept of adaptive management approach."
But on Friday the company filed a notice in the Court of Appeal.
In a statement it said the EPA followed a legally correct approach in granting a marine discharge consent, including adhering to a comprehensive set of conditions specifically designed to protect the marine environment and iwi interests.
Local iwi Ngāti Ruanui spokesperson Debbie Ngarewa-Packer said she was not surprised an appeal had been lodged.
"We got the head's up from our lawyers last week so we're prepared. This company has a lot of face to save with that sort of judgement over their heads so there's no surprises there."
She said opponents would be cross-appealing, which they had 10 days to do.
The Court of Appeal has yet to confirm whether the case will be heard.
If granted, TTR would appeal the High Court's decision that the EPA's decision was inconsistent with the Exclusive Economic Zone Act (EEZA).
In the High Court ruling Justice Churchman said the Act had been "narrowly interpreted" and was inconsistent with the purpose of protecting the environment from pollution by regulating or prohibiting the discharge of harmful substances."
He also said it was inconsistent with the obligation that where information available was uncertain or inadequate, a marine consent authority must favour caution and environmental protection.
Ms Ngarewa-Packer said opposition was based mainly on the latter point.
She said it was not known what the environmental impact could be and research into marine life was scant.
"The Act was put in place to use all precaution and if there's any doubt then the conservative approach should be respected."
She said they were not opposed outright to the activity but more work should be done by TTR.
"We have the largest amount of extraction activity in our backyard so we're extremely savvy. Companies that are best practice come with loads and loads of information.
"They just haven't done enough to provide the hard data - the data can be found if you work hard enough for it."
Last year's decision by the EPA would have allowed TTR to dig up to 50 million tonnes of iron sand from the ocean floor each year, extract five million tonnes of iron ore, and dump the residue back on the bottom of the sea.
The scheme was approved in a split decision, with the chair of the board of commissioners issuing a casting vote in favour.
Approval of the project came after four months of hearings.
In proposing the scheme, TTR said it would produce 300 jobs and add $160 million to New Zealand's GDP.