A remote and largely pristine stretch of ocean off Antarctica received international protection on Friday, becoming the world's largest marine reserve as a broad coalition of countries came together to protect 598,000 square miles of water. The new marine protected area in the Ross Sea was created by a unanimous decision of the international body that oversees the waters around Antarctica - the Commission for the Conservation of Antarctic Marine Living Resources - and was announced at the commission's annual meeting in Tasmania. The commission comprises 24 countries, including the United States, and the European Union. South of New Zealand and deep in the Southern (or Antarctic) Ocean, the 1.9 million square-mile Ross Sea is sometimes called the "Last Ocean" because it is largely untouched by humans. Its nutrient-rich waters are the most productive in the Antarctic, leading to huge plankton and krill blooms that support vast numbers of fish, seals, penguins, and whales.Some 16,000 species are thought to call the Ross Sea home, many of them uniquely adapted to the cold environment. A 2011 study in the journal Biological Conservation called the Ross Sea "the least altered marine ecosystem on Earth," citing intact communities of emperor and Adelie penguins, crabeater seals, orcas, and minke whales. Environmental groups and several countries had pushed for protections for the Ross Sea for decades.