Monday, April 15, 2024

Helicopter Surveys Confirm ‘Extensive Coral Bleaching’ In Southern Great Barrier Reef


Scientists recently took to the skies above the southern Great Barrier Reef, where they confirmed “extensive coral bleaching across the region.”

Great Barrier Reef Marine Park Authority staffers along with scientists from the Australian Institute of Marine Science surveyed 27 inshore reefs in the Keppel Islands and Gladstone region and 21 offshore reefs in the Capricorn Bunkers.

Reef Authority Director for Reef Health Dr. Mark Read said coral bleaching was extensive and fairly uniform across all of the surveyed reefs, with bleaching detected down to the visible depths in clear water across most locations, aligning with observations of accumulated heat stress, adding:

“In the reef communities surveyed most coral cover displayed some level of bleaching with white and fluorescent colonies observed in shallow reef areas.”

AIMS Senior Research Scientist Dr. Neal Cantin said calm conditions across the region provided good visibility:

“We were able to see bleached corals at depth quite clearly across the reef slope from the air.”

Reef Briefing

Earlier this month, the lead Reef Authority managers gave a briefing on how they monitor the health of the world’s largest coral reef — particularly over the summer when it’s most vulnerable to extreme weather events that can cause bleaching.

Briefing slide from Great Barrier Reef Marine Park Authority presentation
Briefing slide from Great Barrier Reef Marine Park Authority presentation

When coral bleaching occurs, it’s a stress response with a result of 90% reduction in the ability to absorb food, according to the managers of the Great Barrier Reef Marine Park Authority. It all but eliminates the ability for corals to reproduce.

While recovery is possible, it’s mainly dependent on the size and species of the coral. Recovery can take between five and 10 years, although additional events could slow or reverse that process.

Among the points raised by the managers were:

• The size of the reef (it’s as big as Italy) makes it incredibly difficult to identify and evaluate bleaching variables

• There hasn’t been, to this point, a Universally Accepted Evaluation System (i.e. terminology standard)

The managers work on three “Focus Areas“:

  1. Reef health year round (not just higher risk summers)
  2. Early Warning Systems
  3. Sea Surface Temperatures

To find out ways to help the Great Barrier Reef, check out the Reef Authority’s Eye on the Reef website or its Reef Guardians program.

Additional reporting by Jennifer Morgan

John Liang
John Liang
John Liang is the News Editor at He first got the diving bug while in High School in Cairo, Egypt, where he earned his PADI Open Water Diver certification in the Red Sea off the Sinai Peninsula. Since then, John has dived in a volcanic lake in Guatemala, among white-tipped sharks off the Pacific Coast of Costa Rica, and other places including a pool in Las Vegas helping to break the world record for the largest underwater press conference.