The Great Barrier Reef is seeing a comeback of fragile coral

Parts of Australia’s beleaguered Great Barrier Reef now have their highest coral cover in decades, according to a government report on Thursday, suggesting the aquatic wonder could survive if given the chance.

Parts of the vast UNESCO World Heritage site have shown a significant increase in coral cover over the past year, reaching levels not seen in 36 years of monitoring, the Australian Institute of Marine Science said.

Scientists surveying 87 sites said the northern and central parts of the reef have recovered from damage faster than some expected, thanks largely to fast-growing acropora – a branching coral that supports thousands of marine species.

“These latest results show that the reef can recover even during periods without strong disturbances,” said Paul Hardisty, CEO of the Australian Institute of Marine Science.

But far from declaring victory, Hardisty warned that gains could easily be reversed by hurricanes, new bleaching events or outbreaks of crowns of thorns.

He pointed to a reversal of fortunes for the southern part of the reef, which appeared to be on the mend a year ago but is now in decline again.

“This shows how vulnerable the reef is to the ongoing acute and severe disturbances that are more frequent and longer-lasting,” he said.

Coral cover has increased by 36 percent at monitored sites on the northern part of the reef, up from 27 percent in 2021.

But the picture was less encouraging as scientists moved south, with a smaller increase in cover in the reef’s central belt and a significant decrease in coral cover in the south.

The proliferation of coral-destroying crown-of-thorns starfish has also taken its toll.

Only fierce lobbying by the Australian government kept the reef from being listed as “under threat” by UNESCO – a potentially devastating blow to the country’s multi-billion dollar tourism industry.

Many fear the rapid damage rate could result in the reef being completely destroyed.

Oceanographer Terry Hughes said it was “good news” that corals are regrowing, but warned the species driving the recovery are highly vulnerable to ocean warming.

He added that it was probably “no longer possible to replace large, old, slow-growing corals that had defined the reef.

Zoe Richards, a researcher in the Coral Conservation and Research Group at Curtin University, also cautioned against over-optimism.

“This recovery trend is being driven by a handful of Acropora species, which often grow in a boom-and-bust pattern,” she said. “This means that the next thermal stress event could easily decimate these coral communities again.”

“We’re already finding evidence that each mass bleaching event leads to localized extinctions of rarer species, so the short-term success of a handful of fast-growing coral species obscures the whole story of largely hidden biodiversity loss.”