Conservationists are criticising the Government for rejecting a plan to set up a marine reserve in Antarctica's Ross Sea with the United States.
The area is widely considered to be one of the most pristine seas on earth, with little pollution or invasive species.
Many scientists have warned that commercial fishing in the Ross Sea threatens the environment and that a "living laboratory" could be lost.
New Zealand submitted its own proposal on Friday to the international grouping which manages the waters around Antarctica. Foreign Affairs Minister Murray McCully said the plan would create the largest Marine Protected Area (MPA) in the world.
Details of the New Zealand plan have not been released, but it is understood that it would allow the controversial toothfish fishery to continue outside the proposed reserve.
Environmentalists say the US plan was more conservation focused and would have placed key fishing grounds inside the reserve.
"This was New Zealand's big opportunity to do something special in the Ross Sea and we've blown it. We've put short term profits ahead of long term gain," said Peter Young, the maker of a documentary on the Ross Sea.
Green Party co-leader Russel Norman believes the fishing industry put pressure on the Government.
"The New Zealand Government didn't want to support a more ambitious protection of the marine environment," he said.
McCully said the Government consulted a range of interests in drafting its proposal.
"New Zealand has a range of complex interests, spanning conservation, as well as science and research as well as the fishing interests we have as well. And we decided that at the initial stages of this process we would submit our own proposals," he said.
He said he discussed the joint proposal with the US but it "didn't work out". But McCully said New Zealand would continue to work closely with the US on the Antarctic.
The international body that manages the Antarctic waters is due to meet in October in Hobart.
To designate an area as protected, the 24 nations plus the EU that make up the Commission for the Conservation of Antarctic Marine Living Resources, must all agree.
Conservationists fear that separate New Zealand and US proposals will undermine the prospect of creating a Ross Sea marine reserve.