Great Barrier Reef bleach ahead of World Heritage Committee ‘in danger’ visit

A new wave of coral bleaching has hit the Great Barrier Reef as a World Heritage Committee delegation arrives to decide if it should be declared ‘in danger’.

Aerial surveys have confirmed a new wave of coral bleaching on parts of the Great Barrier Reef as a World Heritage Committee delegation arrives in Australia to assess whether or not the natural wonder should be declared “in danger”.

The bleaching was widespread but variable across multiple areas ranging from minor to severe, the Great Barrier Reef Marine Park Authority said.

A major survey of the entire reef system by the authority and the Australian Institute of Marine Science is about half complete following a sharp rise in water temperatures.

GBRMPA said the past week had brought cooler temperatures to the reef bringing an end to the heatwave conditions of late February and early March.

“Despite this, sea surface temperatures remain above average across most of the Marine Park and are expected to remain so until the end of March,” it said.

It said weather patterns over the next few weeks would be critical in determining the extent and severity of coral bleaching.

“Most observations of bleaching have been of paling or fluorescing but several locations have whole colonies bleached white”, GBRMPA said, adding there had also been reports of early mortality where heat stress had been the greatest.

The worst-affected reefs were around the Townsville region.

Aerial surveys have not yet been conducted over the major tourism areas such as Cairns and Port Douglas, as heat stress has been less in these areas, and in-water observations suggest that corals there have not been severely affected.

Coral on the Great Barrier Reef has again been hit with bleaching, authorities say. Picture: AFP

The bleaching coincides with the arrival of a reactive mission from the World Heritage Committee to assess Australia’s management of the reef.

The committee will consider whether the reef should be inscribed on the World Heritage “in danger” list at a meeting in June.

A spokesman for Environment Minister Sussan Ley said the mission would have access to all aspects of the reef that it requires to complete its work.

The mission will meet with government as well as environment groups, community stakeholders, traditional owners, industry and scientists.

Ms Ley said any time there was bleaching it was a concern. “This is why we are investing an additional $1bn in the reef to strengthen its resilience in the face of these challenges,” she said.

Funding was going towards advanced management activities that reduce other pressures on the reef and create the maximum possible recovery windows for coral after extreme weather events, she said.

Marine scientist Peter Ridd said it was too early to say how things would play out from the current bleaching event in terms of mortality.

“It must be remembered that some parts of the reef bleach every year,” Dr Ridd said.

But Australian Conservation Foundation chief executive Kelly O’Shanassy said only urgent action on climate change would give the reef a chance to survive.