Spot checks conducted by the Great Barrier Reef Marine Park Authority between Cairns and Townsville have revealed moderate to severe coral bleaching at some reefs. 

The Marine Park Authority conducted 54 in-water spot surveys of six reefs this week following early warning system reports of coral bleaching on the Great Barrier Reef.

Great Barrier Reef Marine Park Authority Chairman Dr Russell Reichelt said all six reefs surveyed had experienced thermal stress, following 12 months of sustained above-average temperatures across the Great Barrier Reef and current sea temperatures approximately 2 degrees Celsius warmer than average.

“Initial survey results showed high levels of bleaching among the most sensitive coral species, with 60 per cent or more affected at some sites,” Dr Reichelt said.

“However, coral species generally resistant to bleaching, such as boulder corals, fared better, displaying a much lower incidence of bleaching.

“Reports of coral bleaching have been increasing over the summer, in the wake of 12 months of sustained above-average temperatures.

“The Marine Park Authority is working closely with its partners in the tourism, fishing and research fields to build a comprehensive picture of the current and anticipated impacts of further coral bleaching.

“The Authority is using its well-established Reef Health Incident Response System, including satellite tools from the Bureau of Meteorology and reports through its Eye on the Reef monitoring network, to gather intelligence and target aerial and in-water surveys.”

Above-average temperatures are predicted until the end of March and into April; however local weather events — such as monsoonal rain — could bring cool relief to Reef waters.

The bleaching incidents on the Great Barrier Reef are part of a global coral bleaching event that has been affecting the world’s coral reefs for at least two years.

“The Great Barrier Reef has fared better than many of the world’s reefs and still offers exceptional visitor experiences with hundreds of reefs across its vast 348,000 square kilometres still in good condition,” Dr Reichelt said.

“The latest coral bleaching strengthens the urgency of the world acting to implement the Paris Agreement to reduce greenhouse gas emissions so average temperature increase remains well below 2 degrees Celsius above pre-industrial levels and preferably below 1.5 degrees Celsius. 

“It also emphasises the importance of the Reef 2050 Plan and the Authority’s ongoing management to build Reef resilience — including its underpinning zoning plan which research indicates is effectively protecting biodiversity across the Great Barrier Reef, compliance actions to stamp out illegal fishing and work to control the coral-eating crown-of-thorns starfish.”