Foreign Minister Murray McCully says he is "optimistic but not confident'' a deal will be reached over a protected marine area in the Ross Sea this week, but will not rule out watering down the proposal further to ensure that happens.

A new round of talks between the 25 countries involved began in Hobart this week on a watered down proposal for a marine protected area, including a smaller area than originally proposed and a sunset clause allowing the countries to alter or scrap the reserve in 50 years.

The proposed reserve was scaled back from 2.27 million sq km to 1.34 million sq km after failing to reach a consensus at a special meeting of the Commission for the Conservation of Antarctic Marine Living Resources in Germany in July. At that meeting, nations including Japan and Norway expressed concern about the permanence of a marine reserve in the Ross Sea - an area many of the countries involved have fishing interests in.

Mr McCully defended the decision to include a sunset clause, saying it could be the only way through. He was also open to a lesser period than the 50 years proposed, saying it was important to leave the negotiation team room to move.


"Clearly for countries that feel most uncomfortable about the marine protected area, the back door of a sunset clause is an important issue, and to take it off the table would be to undermine the talks.''

He said groups which were pushing for a marine reserve had been critical of scaling back the proposal. "Some modifications were made to the proposal, and there may be more yet. But those groups need to understand that getting 25 countries to agree is going to be challenging.''

Talks were underway with countries such as Russia which was also resistant to the marine reserve, and he said engagement in the lead up to the meetings had been positive.

The proposal considered in July was a joint US-New Zealand proposal and Mr McCully said he had been in discussions with US Secretary of State John Kerry about the reserve. Mr Kerry has publicly backed the need for it.