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Great Barrier Reef bursts back to life... but climate change still poses a threat

Great Barrier Reef - Australian Institute of Marine Science
Great Barrier Reef - Australian Institute of Marine Science

Australia’s Great Barrier Reef is bursting back to life in remarkable fashion after being damaged by warming waters, a new investigation has revealed.

The world heritage site is currently boasting its greatest coral cover in decades. However, experts cautioned that the regrowth was made up largely of a common, fast-growing but weak genus known as acropora that could easily be lost.

Acropora is renowned for its branching colonies that resemble staghorns and can grow in thickets covering large areas in a variety of colours.

It also plays a key role in reef building, providing a large percentage of the calcium carbonate structure, and is tied to the popular imagination of the Great Barrier Reef, frequently being pictured on postcards.

However, it is particularly vulnerable to storms and crown-of-thorns starfish, which feed on coral, and often grows in “boom and bust” cycles.

Great Barrier Reef - Australian Institute of Marine Science
Great Barrier Reef - Australian Institute of Marine Science

The reef, which stretches for nearly 1,500 miles along the coast of Queensland, has been badly impacted by climate change in recent years and has suffered a series of “mass bleaching” events, where stressed coral turns white.

However, scientists revealed that the northern and central parts of the reef now have the highest amount of coral cover since monitoring began 36 years ago.

A question mark remains over the exact reason for the reef’s sudden recovery, which suggests that the ecosystem has much greater resilience and ability to recover than previously understood.

It may have been helped by a relatively quiet period in terms of cyclones and crown-of-thorns starfish, which means the progress could be undone by further disturbances.

Dr Mike Emslie, the research programme leader from the Australian Institute of Marine Science, said that the results were “good news” but that there were still major worries about the reef’s health.

Prof Terry Hughes, a marine scientist, said that replacing the large, old, slow-growing corals that had previously defined the reef was likely “no longer possible”, adding: “Instead we’re seeing partial reassembly of fast-growing, weedy corals before the next disturbance.”

Great Barrier Reef - Australian Institute of Marine Science
Great Barrier Reef - Australian Institute of Marine Science

Dr Paul Hardisty, the chief executive of the Australian Institute of Marine Science, said “These latest results demonstrate the reef can still recover in periods free of intense disturbances.”

He also warned that the increased frequency of mass coral bleaching caused by climate change was “uncharted territory” for the reef and that a bleaching event earlier this year was the first to occur during a La Nina weather pattern.

Dr Maxine Newlands, a political scientist from the James Cook University in Queensland, said that the reef’s survival depended on a delicate balancing act.

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

Great Barrier Reef - EyesWideOpen/Getty Images
Great Barrier Reef - EyesWideOpen/Getty Images

The Great Barrier Reef is one of the world’s most spectacular marine environments and attracted thousands of tourists a year in pre-pandemic times.

It created an estimated 64,000 jobs and generated nearly £3.5 billion a year for the Australian economy.

The reef has been on Unesco’s World Heritage list since 1981 because of its scientific significance as one of the most diverse ecosystems on the planet.

However, officials from Unesco’s World Heritage Committee, which inspected the reef earlier this year, have accused Australian authorities of not doing enough to protect it.

There are fears it could be listed as “in danger”, which would reflect poorly on Australia’s environmental credentials and damage the image of one of the country’s prime tourist attractions.