At 135,000 square miles, the Great Barrier Reef reigns as the world’s largest living structure. Located off the northeastern coast of Australia, it houses more than 600 species of coral and thousands of other types of marine animals, too. Yet the reef’s future looks bleak. In the 27 years from 1985 to 2012, half of its coral cover vanished. A significant proportion of the loss is attributable to climate change, which has strengthened destructive tropical cyclones and made surrounding waters warmer and more acidic. Conservation efforts alone, including protected zones and water-quality improvements, will not do the job. To further combat coral loss, marine biologists at a new research facility in Australia, called the National Sea Simulator, have devised a more radical approach: they are manually breeding supercorals capable of living in the increasingly inhospitable sea.