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 discovery of the die-off in the reef's north is a major blow for tourism, which according to a 2013 Deloitte Access Economics report, attracts about AU$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, said by telephone from Townsville in Australia's tropical north.