2 December 2016, Reuters, Biggest-Ever Coral Die-Off Reported on Australia’s Great Barrier Reef. Warm seas around Australia’s Great Barrier Reef have killed two-thirds of a 700-km (435 miles) stretch of coral in the past nine months, the worst die-off ever recorded on the World Heritage site, scientists who surveyed the reef said on Tuesday. Their finding of the die-off in the reef’s north is a major blow for tourism at reef which, according to a 2013 Deloitte Access Economics report, attracts about A$5.2 billion ($3.9 billion) in spending each year. “The coral is essentially cooked,” professor Andrew Baird, a researcher at James Cook University who was part of the reef surveys, told Reuters by telephone from Townsville in Australia’s tropical north. He said the die-off was “almost certainly” the largest ever recorded anywhere because of the size of the Barrier Reef, which at 348,000 sq km (134,400 sq miles) is the biggest coral reef in the world. Bleaching occurs when the water is too warm, forcing coral to expel living algae and causing it to calcify and turn white. Mildly bleached coral can recover if the temperature drops and the survey found this occurred in southern parts of the reef, where coral mortality was much lower. Read More here