MELBOURNE: The Great Barrier Reef has been hit by bleaching due to heat stress, the Australian agency that manages the reef said on Friday, ahead of a visit by United Nations officials reviewing whether the reef should be listed as being “in danger”.

Australia last year dodged an “in danger” listing for the reef, a World Heritage site, for a second time, after heavy lobbying by Unesco to postpone a decision to this year.

The Great Barrier Reef Marine Park Authority said in a weekly update most of the marine park had been hit by “significant heat stress” over the summer, with water temperatures in some areas as much as 2-4 degrees Celsius above average.

“Bleaching has been detected across the Marine Park - it is widespread but variable, across multiple regions, ranging in impact from minor to severe,” the agency said in an update on its website.

Aerial surveys showed whole colonies of coral had been bleached white in several locations, and in some sections there were reports of corals dying, it said.

“Corals across the Marine Park remain vulnerable to the ongoing elevated temperatures,” the authority said.

Unesco experts will be in Australia for 10 days from March 21 to meet scientists, regulators, policymakers from the Australian and Queensland state governments, and members of the public, a federal environment department spokesperson said.

Published in Dawn, March 19th, 2022