The Great Barrier Reef is the world’s largest expanse of coral reefs. It is home to an astonishing diversity of life and vital to the health of our seas. But this extraordinary place and all the life it supports is under threat like never before. To find out what the future holds for one of Earth’s greatest natural wonders, a team of scientists have based themselves on Heron Island, at the southern tip of the reef, to monitor green turtles, follow families of breeding birds and meet the reef’s curious residents.