ScienceGreat Barrier Reef in danger To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoScienceJessie Wingard07/18/2017July 18, 2017The Great Barrier Reef, the earth's biggest single structure made by living organisms, is endangered by coral bleaching and global warming. It was declared a UNESCO World Heritage Site in 1981. https://p.dw.com/p/2gixEAdvertisement