Russia on Tuesday blocked attempts by Western countries to create the world's largest ocean sanctuary off Antarctica, green groups said.
The Russian representative questioned the legal right of a meeting in Bremerhaven, northern Germany, to declare such a haven, according to organisations at the talks.
The three-day talks gathered 24 nations plus the European Union (EU) in the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), a 31-year-old treaty tasked with overseeing conservation and sustainable exploitation of the Southern Ocean.
One proposal, floated by the United States and New Zealand, covered 1.6 million square kilometres (640,000 square miles) of the Ross Sea, the deep bay on Antarctica's Pacific side.
The other, backed by Australia, France and the EU, would protect 1.9 million sq. km of coastal seas off East Antarctica, on the frozen continent's Indian Ocean side.
Protecting those areas -- which biologists say are rich in unique species -- would more than double the amount of ocean sanctuary in the world.
Andrea Kavanagh, in charge of the Southern Ocean Sanctuaries campaign at the US green group Pew Environment, told AFP that Russia had refused to negotiate, saying simply that it questioned the legal status of CCAMLR to declare such zones.
"The actions of the Russian delegation have put international cooperation and goodwill at risk, the two key ingredients needed for global marine conservation," she said.
"After two years of preparation, including this meeting, which Russia requested to settle the scientific case for the Ross Sea and East Antarctic proposals, we leave with nothing," said Steve Campbell, director of the Antarctic Ocean Alliance (AOA) of green groups.
"All members, except Russia, came to this meeting to negotiate in good faith," he said in a press statement.
Parties met in Hobart, Australia, last October, but failed to reach a deal because of opposition by China and Russia, supported by Ukraine, which said restrictions on fishing were too onerous.
As a result, they agreed to an exceptional meeting this July. It was only the second time that the CCAMLR has met outside its annual gathering.
The fate of the proposed marine sanctuaries lies in the next annual meeting of CCAMLR in Hobart, running from October 23-November 1, the sources said.