Great barrier reef national geographic video
Mar 21, · Scientists have discovered an unprecedented die-off in the world's largest reef, the Great Barrier Reef, prompting the Australian government to issue its highest response level. Diver surveys. The largest living structure, the Great Barrier Reef spans more than 1, miles (2, kilometers) of islands and submerged reefs. A plethora of coral thrives here, along with a sweep of parrotfish, surgeonfish, barracuda, and sharks. Narrated by National Geographic Explorer-in . Jun 20, · The Great Barrier Reef lies in tropical waters where temperatures are warm enough to offer enjoyable swimming and diving year round—though averages can vary 10°F (°C) from winter to .