Frustrated with the pace of the United Nations group charged with protecting Antarctic waters, a coalition of environmental groups announced its own initiative on Tuesday, calling for the creation of what would be the world?s largest network of marine reserves in the Southern Ocean.

The Antarctic Ocean Alliance, which includes environmental and conservation organizations like Greenpeace, WWF, and the International Fund for Animal Welfare and the American oceanographer Sylvia Earle, is proposing that 19 areas be set aside as marine protected areas or no-take zones where fishing and mineral exploration are prohibited.

Many fisheries scientists argue that such reserves offer the best hope for restoring ecosystems stressed by overfishing, pollution and global warming. United Nations members meeting in Nagoya, Japan, agreed in October 2010 to set aside 10 percent of the world?s oceans as reserves by 2020 under theConvention on Biological Diversity, a target that all agree remains distant.

The body charged with overseeing the Southern Ocean habitat, theCommission for the Conservation of Antarctic Marine Living Resources, is planning to discuss proposals from the United States and New Zealand for the creation of some reserves when it meets in late October in Hobart, Tasmania.

But the alliance argues that the commission, which does not allow the news media to cover its meetings and tightly controls access by environmental groups, will invariably fall short of what is needed without greater public scrutiny.

Antarctic waters, which account for about 10 percent of the world?s oceans, are home to 10,000 species including penguins, seals and whales, according to the alliance.

James N. Barnes, executive director of the Antarctic and Southern Ocean Coalition, said that scientists were deeply troubled by the expansion of the Antarctic toothfish industry in the Ross Sea, largely by New Zealand fishermen. The toothfish, often marketed as Chilean sea bass, is a slow-growing apex predator prized for its flesh.

??To this day, they don?t know the most basic things about these fish,?? Mr. Barnes said. A booming fishery for krill, one of the bedrocks of the ecosystem, is also a concern, he said.

Under the precautionary principle built into the Antarctic commission?s charter, environmentalists argue, fishing should be curtailed in the absence of adequate stock assessments.

The proposed network of marine reserves, spanning 1.39 million square miles, would be more than twice the size of Alaska and a first step toward the creation of a larger network to protect the Southern Ocean. Currently, the Chagos Islands marine protected area in the Indian Ocean, at 210,000 square miles, is the world?s largest such zone.

??The waters of Antarctica have become attractive for industrial scale fishing because fish close to where people live really don?t exist in large numbers anymore,?? Dr. Earle said in a statement announcing the initiative. ??We know we have a problem. We now need to do something about it.??