Icy cliffs along the Antarctic coast tower over the Ross Sea.
Credit: John B. Weller

Antarctica and the Southern Ocean around it are awash in superlatives—the coldest and driest continent, the windiest seas. And now they add another: home to the largest protected area in the world. The Ross Sea Region Marine Protected Area (MPA), which covers 2.06 million square kilometers (almost 800,000 square miles) enters into force today, one year after the 25 member governments of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) agreed by consensus to designate the area. That decision showed that the commission takes its role as guardian of Antarctica’s Southern Ocean waters seriously.

By coincidence, Dec. 1 is also World Antarctica Day, and with the entry into force of this MPA, which includes the 500,000-square-kilometer (193,00-square-mile) Ross Ice Shelf, the region that scientists have called “the least altered marine ecosystem on Earth” has an excellent chance of remaining so.

The new protected area safeguards the foraging ranges of significant percentages of the world’s populations of Adélie […]