Great Barrier Reef at 'terminal stage': scientists despair at latest coral bleaching data

Back-to-back severe bleaching events have affected two-thirds of Australia’s Great Barrier Reef, new aerial surveys have found.

Aerial surveys of the world’s largest
living structure, scoring bleaching
at 800 individual coral reefs
 across 8,000km.

The findings have caused alarm among scientists, who say the proximity of the 2016 and 2017 bleaching events is unprecedented for the reef, and will give damaged coral little chance to recover.

Scientists with the Australian Research Council’s Centre of Excellence for Coral Reef Studies last week completed aerial surveys of the world’s largest living structure, scoring bleaching at 800 individual coral reefs across 8,000km.

The results show the two consecutive mass bleaching events have affected a 1,500km stretch, leaving only the reef’s southern third unscathed.

Where last year’s bleaching was concentrated in the reef’s northern third, the 2017 event spread further south, and was most intense in the middle section of the Great Barrier Reef. This year’s mass bleaching, second in severity only to 2016, has occurred even in the absence of an El Niño event.

Read The Guardian story Christopher Knaus and Nick Eversed - “Great Barrier Reef at 'terminal stage': scientists despair at latest coral bleaching data.”

‘Huge blow': Back-to-back bleaching covers two-thirds of the Great Barrier Reef

Unprecedented back-to-back annual coral bleaching events have affected two-thirds of the Great Barrier Reef, with this year's event already leading to mortality of half the corals in some key tourist tracts, scientists say.

The aerial survey plotted the health of 
some 800 reefs over 8000 km of flying. 

Record-breaking warm waters along the Queensland coast has triggered widespread bleaching over 1500 kilometres of the World-Heritage-listed reef over the two summers, said Terry Hughes, director of the ARC Centre of Excellence for Coral Reef Studies.

Professor Hughes and his team completed aerial surveys last Wednesday after scoring about 800 separate reefs. The 8000km journey closely followed the path of the 2016 survey that found the northern regions of the Great Barrier Reef most affected.

This year, the worst of the bleaching is further south in the popular tourist sector between Townsville and Cairns. (See map below.)

Read Peter Hannam’s story in today’s Melbourne Age - “‘Huge blow': Back-to-back bleaching covers two-thirds of the Great Barrier Reef.”