Great Barrier Reef shows resilience, but caution stressed

It was not that long ago that the future of Australia's Great Barrier Reef was looking bleak as climate change took its toll on one of the world's great natural wonders. But all is not lost, according to the Australian Institute of Marine Science, which has been monitoring the reef's health for nearly four decades.

In a report, the institute said the northern and central parts of the 2,300-kilometer-long reef, which runs down the coast of the northeastern state of Queensland, are on the mend after an "extensive bout" of disturbances over the past decade.

The reef has been hit hard by rising temperatures in recent years. In 2016 and 2017, underwater heat waves triggered coral bleaching events so severe that experts worried that the reef would never look the same again.

Last year, the United Nations Educational, Scientific and Cultural Organization warned that it could add the Great Barrier Reef to a list of World Heritage sites that are "in danger".

'Global icon'

Maxine Newlands, a political scientist at James Cook University in Queensland, notes that the reef is a "global icon".

While news of the recovery and resilience of the world's largest ecosystem is welcome, any future disturbances, such as intense tropical cyclones, have the potential to cause loss of coral cover back to their levels in 2016 and 2017 in the northern and central zones, according to Newlands.

"Politicians and policymakers cannot see this as a sign of a recovered reef, but as an indicator that more needs to be done," she said.

Despite the good news, parts of the southern sections of the reef have been decimated by crown-of-thorns starfish, which feed exclusively on live coral, scientists said.

Among the 87 reefs surveyed for the latest report by the institute, average hard coral cover in the north increased to 36 percent, from 27 percent in 2021; and to 33 percent, from 26 percent, in the central Great Barrier Reef. However, the average coral cover in the southern region decreased from 38 percent in 2021 to 34 percent this year.

Zoe Richards, a senior research fellow who leads the Coral Conservation and Research Group at Australia's Curtin University, said the report's findings were "good news".

"The finding that coral cover has already reached comparative high levels in the northern and central sectors is good news because the corals provide habitat for thousands of other plants and animals," Richards said.

She said the findings of increased coral cover are also good for the tourism industry, as reefs with high coral cover are often visually spectacular. However, as stated in the report, the recovery trend is driven by a handful of Acropora species or coral which often grow in a highly irregular pattern, Richards said.

Peter Mumby, a professor at the Marine Spatial Ecology Lab and School of Biological Sciences at the University of Queensland, said it was encouraging to see the recovery of the reef. "What this shows is that the ecosystem still has great resilience," he said.