Great Barrier Reef records highest coral cover in parts

Two-thirds of Australia's Great Barrier Reef showed the highest levels of coral cover seen in decades, but the reef remained vulnerable to increasingly frequent mass bleaching, a new report released on Thursday showed.

The report by the Australian Institute of Marine Science outlined how the survey of 87 sites said northern and central parts of the reef showcased a comeback from damage more quickly than many had expected, mostly because of a fast-growing type of branching coral, called the Acropora.

"These latest results demonstrate the reef can still recover in periods free of intense disturbances," said AIMS's CEO Paul Hardisty. But the gains made could easily be reversed by cyclones, new bleaching events, or crown-of-thorns outbreaks.

Varied progress across the reef

In the northern parts of the reef, the average hard coral cover grew to 36% in 2022, up from a low of 13% in 2017. The central region also showed improvement with hard coral cover increasing to 33% from a low of 12% in 2019. 

These are the highest levels recorded for both regions since the institute began monitoring the reef in 1985.

"What we're seeing is that the Great Barrier Reef is still a resilient system. It still maintains that ability to recover from disturbances," said AIMS monitoring program leader Mike Emslie.

However, the southern region — which generally has higher hard coral cover than the other two — saw a reduction to 34% in 2022, down from 38% a year earlier.

This comes after the fourth mass bleaching in seven years and the first during a La Nina event, which is usually associated with cooler temperatures.

"But the worrying thing is that the frequency of these disturbance events are increasing, particularly the mass coral bleaching events," Emslie said.

Australia under pressure

The latest report comes as UNESCO considers whether to list the Great Barrier Reef as "in danger," following a visit by UNESCO experts in March this year. The decision was to be made at the World Heritage Committee meeting in Russia this June but was postponed.

The Australian government has been lobbying against the reef being labeled "in danger" by the UN agency, as it could potentially impact the country's multi-billion-dollar tourism industry.

see/msh (Reuters, AFP)