Scientists record biggest ever coral die-off on Australia's Great Barrier Reef

Researcher Grace Frank completes bleaching surveys along a transect line on an area known as One Tree Reef, in the ...
HANDOUT

Researcher Grace Frank completes bleaching surveys along a transect line on an area known as One Tree Reef, in the Capricorn Group of Islands, on the Great Barrier Reef in Australia.

Warm seas around Australia's Great Barrier Reef have killed two-thirds of a 700-km 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 (NZD$5.5 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.

Dead table corals killed by bleaching on Zenith Reef, on the northern Great Barrier Reef in Australia.
HANDOUT

Dead table corals killed by bleaching on Zenith Reef, on the northern Great Barrier Reef in Australia.

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 is the biggest coral reef in the world.

READ MORE:
Mystery surrounds deaths on Great Barrier Reef
No, the Great Barrier Reef in Australia is not dead - but it is in trouble
Coral bleaching distressing Great Barrier Reef wildlife
It's hard to find Dory on the Great Barrier Reef

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.

Oliver Lanyon, senior ranger in the Great Barrier Reef region for the Queensland Parks and Wildlife Service, takes ...
DAVID GRAY/Reuters

Oliver Lanyon, senior ranger in the Great Barrier Reef region for the Queensland Parks and Wildlife Service, takes photographs and notes during an inspection of the reef's condition in an area called the "Coral Gardens" located at Lady Elliot Island and 80 kilometres north-east from the town of Bundaberg in Queensland, Australia in 2015.

While bleaching occurs naturally, scientists are concerned that rising sea temperatures caused by global warming magnifies the damage, leaving sensitive underwater ecosystems unable to recover.

UNESCO's World Heritage Committee stopped short of placing the Great Barrier Reef on an "in danger" list last May but asked the Australian government for an update on its progress in safeguarding the reef.

Australia will lodge that update on Friday, said a spokesman for Environment Minister Josh Frydenberg. In June, during an election campaign, Prime Minister Malcolm Turnbull promised A$1 billion in spending to protect the reef.

Climate scientists argue that increased carbon dioxide in the atmosphere traps heat radiating from earth, creating global warming. Australia is one of the largest carbon emitters per capita because of its reliance on coal-fired power plants for electricity.

500

Cannot serve request to /content/desktop/stuff/environment/87014912/Scientists-record-biggest-ever-coral-die-off-on-Australias-Great-Barrier-Reef.html on this server