File photo of Great Barrier Reef
(Picture: AFP via Getty Images)Australia’s Great Barrier Reef has experienced another mass bleaching event, a sign of damage caused by warming sea waters, officials have said.
It is the fourth time in six years that severe damage to the world’s largest reef system has been detected.
Until 2016, only two mass bleaching events had been recorded at the reef.
The announcement comes after the Great Barrier Reef Marine Park Authority conducted aerial surveys of a representative sample of the 1,400 mile reef system.
Bleaching occurs when corals expel the algae within them, which sustain life and give them their distinctive colour.
There is particular concern that the mass bleaching is happening in the same year as a La Niña weather event, which typically brings cooler sea temperatures to Australia.
“It is important to note that bleached coral is stressed but still alive,” said park officials in a statement.
“If conditions moderate, bleached corals can recover from this stress, as was the case in 2020 when there was very low coral mortality associated with a mass bleaching event.
“Weather patterns over the next couple of weeks continue to remain critical in determining the overall extent and severity of coral bleaching across the Marine Park.”
The rate of bleaching has varied across the reef’s zones, with some only seeing minor bleaching and others being affected more severely, with “some mortality” observed.
“Mass bleaching events do not affect every reef, and even those reefs affected are not all equally affected,” the statement added.
Stretching over 1,400 miles off the coast of Queensland, the Great Barrier Reef is one of the most biodiverse ecosystems in the world.
Last year, Unesco scientific advisers recommended the reef be placed on a list of world heritage sites that are “in danger” amid concern over warming sea temperatures.
However, the Australian Government controversially lobbied for an exemption. While it has recently pledged money towards reef-protection measures, critics have claimed these do not go far enough.
