Tense international relations could sway the outcome of vital research and protection proposals for the Antarctic, the head of a global meeting of scientists says.

Russia and China are among 25 delegate nations meeting in Hobart for the annual gathering of the Commission for the Conservation of Antarctic Marine Living Resources.

Representatives from both countries, and others including Ukraine, have previously opposed the creation of two huge marine protected areas, arguing the zones would have a devastating impact on fishing.

This year the commission will again consider the establishment of the ocean sanctuaries – in an amended form – one of which is proposed by Australia, France and the EU, the other by the US and New Zealand.

But international relations, including Australia’s strained links with Russia, could affect the talks.

“No one hangs their coat and hat up at the door, some of those issues come through,” the commission secretary, Australia’s Andrew Wright, told reporters on Monday’s opening day of the meetings.

“We do expect, and it is not unreasonable in a multilateral setting such as this, that there are other issues going on ... that do impact on a member’s political position.”

All 25 delegate nations were represented at this year’s meeting, Wright confirmed.

Talks had been going on between Australian and Russian delegations, but they had been affected by the MH17 tragedy, he said.

“How that plays out over the next fortnight I can’t forecast.”

The agenda for the 10-day meeting includes setting up protected marine areas, combating illegal fishing, limiting catches of krill and other fish species and improving monitoring of Antarctic waters.

The marine park proposal, which Australia has put its name to, has almost halved in size to one million square kilometres since it was last considered by the commission. It also allows restricted fishing activity in its new guise.

The chairman of the commission’s scientific committee, Christopher Jones from the United States, said the initial response to the proposal has been positive.

“It is very important that we make some progress this year,” Jones said of plans for the marine park, which are being considered for a fourth year.