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

Worst die-off ever recorded on the World Heritage site: scientists
Published November 29, 2016

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.

A man snorkels in an area called the "Coral Gardens" near Lady Elliot Island, on the Great Barrier Reef, northeast of Bundaberg town in Queensland, Australia. —Reuters
A man snorkels in an area called the "Coral Gardens" near Lady Elliot Island, on the Great Barrier Reef, northeast of Bundaberg town in Queensland, Australia. —Reuters

"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.

Supplied image of dead table corals killed by bleaching on Zenith Reef, on the northern Great Barrier Reef in Australia. — Reuters
Supplied image of dead table corals killed by bleaching on Zenith Reef, on the northern Great Barrier Reef in Australia. — Reuters

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.

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.

Supplied image of a scientist assessing coral mortality on Zenith Reef on the Great Barrier Reef in Australia. — Reuters
Supplied image of a scientist assessing coral mortality on Zenith Reef on the Great Barrier Reef in Australia. — Reuters

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.

Supplied image of researcher Grace Frank completing 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. — Reuters
Supplied image of researcher Grace Frank completing 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. — Reuters

"Climate change is killing the Great Barrier Reef," said environmentalist Charlie Wood, director of 350.org, an anti-fossil fuels movement.

"The continued mining and burning of coal, oil and gas is irreparably damaging the climate. If we want our kids to enjoy the Great Barrier Reef for generations to come, we must act now to keep fossil fuels in the ground," Wood said in an emailed statement.

Oliver Lanyon, senior ranger in the Great Barrier Reef region for the Queenlsand 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. — Reuters
Oliver Lanyon, senior ranger in the Great Barrier Reef region for the Queenlsand 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. — Reuters