"The Great Barrier Reef is one of the world's natural wonders, covering an area larger than Italy and drawing nearly 2 million tourists every year to boat, swim, snorkel and dive amid its elaborate flora and fauna. It generates some $6 billion in revenue for Australia annually and provides employment to more than 50,000 people. It's also one of the planet's most fragile ecosystems, home to more than 11,000 species that live, if not necessarily in harmony, in a carefully orchestrated symbiotic balance. At the foundation of this giant ecological and commercial enterprise is one tiny marine organism: the coral.
That foundation is no longer solid. Corals build colonies that secrete calcium carbonate to form ocean reefs. When they're healthy, coral reefs provide shelter and food for animals all along the food chain, including the top: us. Across the planet, half a billion people rely, directly and indirectly, on corals for their living. That's why what happens to the 9,000-year-old Great Barrier Reef, as well as to other reefs worldwide, is critical. The recent Queensland floods were most notably tragic for the lives lost and property destroyed. But they have also hurt the Great Barrier Reef by funneling into the ocean vast plumes of freshwater and agricultural runoff that could severely damage the coral. Besides the extreme rain that sparked the floods, rising ocean temperatures, changes to the ocean's chemistry and the global trade in natural resources — all symptoms of our fossil-fuel economy — are waging a multifront war on the marine environment."