Great Barrier Reef sees fragile coral comeback

SYDNEY

Parts of Australia’s beleaguered Great Barrier Reef now have the highest levels of coral cover seen in decades, a government report said Thursday, suggesting the aquatic wonder could survive given the chance.

Portions of the vast UNESCO heritage site showed a marked increase in coral cover in the last year, reaching levels not seen in 36 years of monitoring, the Australian Institute of Marine Science said.

Scientists surveying 87 sites said northern and central parts of the reef had bounced back from damage more quickly than some had expected, thanks mainly to fast-growing Acropora, a branching coral that supports thousands of marine species.
“These latest results demonstrate the reef can still recover in periods free of intense disturbances,” said the Australian Institute of Marine Science’s CEO Paul Hardisty.
But far from declaring victory, Hardisty warned the gains could easily be reversed by cyclones, new bleaching events or crown-of-thorns outbreaks.

He pointed to a reversal in fortunes for the southern portion of the reef, which a year ago had appeared to be on the mend, but was now in decline again.
“This shows how vulnerable the reef is to the continued acute and severe disturbances that are occurring more often, and are longer-lasting,” he said.
Coral coverage has increased by 36 percent across sites monitored in the northern part of the reef, up from 27 percent in 2021.

But the picture was less encouraging as the scientists moved south, with a smaller increase in cover in the reef’s central belt and a marked decrease in coral cover in the south.
The spread of coral-killing crown-of-thorns starfish has also taken a toll.
Only fierce lobbying by the Australian government stopped the reef from being labelled “in danger” by UNESCO, a potentially devastating blow to the country’s multi-billion-dollar tourism industry.
Many fear that the speeding rate of damage could cause the reef to be destroyed entirely.
Marine scientist Terry Hughes said it was “good news” that coral was regrowing, but warned the species driving the recovery were very vulnerable to ocean heating.
He added that replacing large, old, slow-growing corals that had defined the reef was likely “no longer possible. Instead, we’re seeing partial reassembly of fast-growing, weedy corals before the next disturbance.”