Coral cover around Great Barrier Reef islands has almost halved over the last 18 years, says a new study.
Scientists monitored data collected at 100 locations across Whitsundays, Magnetic Island, Keppel Islands and Palm Islands between 1999 and 2017.
Published in the Ecological Society of America’s Ecological Applications journal, the study found hard coral was hit by multiple impacts including heat stress causing bleaching, cyclones, flood plumes and poor water quality.
Daniela Ceccarelli, of James Cook University, said: “The loss was between 40 and 50% at each island group. We were pretty shocked actually.”
She said that faster-growing corals could recover after about seven to 10 years, but for a community that included slower-growing corals, recovery was 15 to 20 years.
The reef, the world’s biggest coral reef system, was hit by major bleaching events in 2016 and 2017.
She added: “It’s definitely not too late to save the reef. It’s not dead, but it might be on intensive care.”