Two-thirds of Australia’s Great Barrier Reef has the highest amount of coral cover in 36 years, but the reef remains vulnerable to increasingly frequent mass bleaching, the official long-term monitoring program said on Thursday. ).
The recovery in the central and northern reaches of the UNESCO World Heritage-listed reef contrasts with the southern region, where there has been a loss of coral cover due to outbreaks of crown of thorns starfish, the Australian Institute of Marine Science said. (AIMS) in its annual report.
“What we’re seeing is that the Great Barrier Reef is still a resilient system. It still retains that ability to recover from disturbances,” AIMS monitoring program leader Mike Emslie told Reuters.
“But what’s worrying is that the frequency of these disturbance events is increasing, particularly massive coral bleaching events,” Emslie said.
The report comes as UNESCO is considering whether to list the Great Barrier Reef as “endangered” following a visit by experts in March. The World Heritage Committee meeting, where the reef’s fate was on the agenda, was supposed to be held in Russia in June but was postponed.
In a key measure of reef health, the AIMS defines stony coral coverage of more than 30% as a high value, based on its long-term research.
In the northern region, average coral coverage grew to 36% in 2022 from a low of 13% in 2017, while in the central region, coverage increased to 33% from a low of 12% in 2019 – the highest levels recorded for both. regions since the institute began monitoring the reef in 1985.
In the southern region, however, which generally has greater stony coral cover than the other two regions, coverage has dropped to 34% in 2022 from 38% the year before.
The recovery comes after the fourth mass bleaching in seven years and the first during a La Nina event, which typically brings cooler temperatures. While extensive, the institute said, the phenomenon in 2020 and 2022 was not as damaging as it was in 2016 and 2017.
On the downside, cover growth was driven by Acropora corals, which AIMS said are particularly vulnerable to wave damage, heat stress and crown of thorns starfish.
Source: CNN Brasil
