Without it, penguins, sea birds, whales and other animals that feed on krill around the Antarctic Peninsula will be at risk of undernourishment or starvation.

“There is bound to be a thorough debate around it,” Dr. Reiss said in a telephone call from Hobart. “Fisheries want to take all their catch from areas where they already fish. They don’t want to take it from areas where they don’t fish. That’s the opposite of being precautionary.”

The Commission for the Conservation of Antarctic Marine Living Resources is made up of the European Union and 24 other nations that have economic or research interests in the Antarctic.

The commission regulates fishing near Antarctica, and works by consensus. If one country blocks a measure, it fails. Last year, Russia blocked a proposal for two huge marine parks, each larger than Texas. Those parks, and a third, are back on the agenda during two weeks of closed-door meetings, which began Monday.

The Antarctic has long been an area of dispute for conservationists and commercial fishing interests. In 2015, 12 fishing vessels caught about 225,466 tons of krill in three of the designated areas around the Bransfield Strait. “We know the fisheries like to concentrate here,” said Andrea Kavanagh, a director of the Southern Ocean Sanctuaries Campaign at Pew Charitable Trusts.

During the 1970s and 1980s more fishing took place off the east coast, when the Soviet Union trawled Antarctic waters. But fishing off the Antarctic Peninsula is more profitable. It is close to Chile and more easily accessible, and the weather permits fishing almost year round.