A joint New Zealand - United States proposal for the world's largest marine reserve in Antarctic waters could be pared back in an attempt to get opposing countries onside.

Delegates from 25 nations with Antarctic interests will meet in Hobart next month where another attempt will be made to get a consensus on a massive network of no-take zones, restricted fishing areas and fishing tagging programmes in the Ross Sea.

The proposed marine protected reserve was rejected at a special meeting in Bremerhaven, Germany in July after it was challenged by countries with fishing interests, in particular Russia and Ukraine. It needed the approval of all 25 countries to go ahead.

Now it was believed that the reserve would be altered to win the support of opponents.


Foreign Affairs Minister Murray McCully, speaking from the Marshall Islands, said New Zealand officials "had been reflecting on whether modifications to the plan will help us get it across the line".

The suggestion of modifications worried conservationists, who felt that the MPA already made too many concessions.

It already allowed fishing in crucial spawning zones and only required tagging of 1 in 10 fish for research.

Mr McCully said the considerations were part of the ongoing diplomatic process to get the marine reserve approved.

"When I said early in the piece that people were underestimating the challenge of getting 25 countries, each with different interests, to agree on this issue, I think people thought I was probably doing a bit of political positioning.

"I actually meant it, and its proving as difficult as I expected to be."

Asked whether he was optimistic about getting the reserve approved at the Hobart meeting, he replied: "No I'm not."

There were already fishing restrictions in the Ross Sea, including a quota of 3800 tonnes a year, but the New Zealand-US proposal would have moved vessels away from some historical fishing grounds and spawning areas in an attempt to make the fishery more sustainable.