Barrier Reef
Summer between 2016 and 2017 was tough for the Great Australian Barrier Reef. Warming above-normal waters killed more than a third of the central and northern parts of the barrier and 93% of the reefs lost their color.
The phenomenon, called bleaching, happens when corals experience stressful situations - too hot or of poor quality water. The imbalance caused breaks the symbiosis of the corals with bacteria called zooxanthellae, which are responsible for the pigmentation of the coral.
Researchers at the Reef & Rainforest Research Center (RRRC), an Australian nonprofit entrepreneurial organization, however, found that if ideal conditions return, zooxanthellae will return as well.
They realized this in the most practical way possible. Recent photos taken in June and July 2018 show healthy and vibrant corals in various locations that suffered during the 2016 and 2017 coral bleaching events.
The RRRC, in cooperation with the Association of Marine Park Tour Operators (AMPTO), conducted detailed surveys on bleaching levels at the top diving tourism sites in Cairns in 2016.
Although many major dive sites were not affected by bleaching in 2016, some were heavily affected by the 2017 event. Fortunately, these are the same reefs that show strong signs of recovery, benefited by a milder summer.
“It's important to realize that bleaching occurs in multiple stages, ranging from the equivalent of a slight sunburn to coral mortality - so when a reef is reported as 'bleached' in the media, it often misses the critical detail of the reef. what the bleaching is, how deep the bleaching has occurred and whether it will permanently damage the coral there, ”said Sheriden Morris, RRRC director general.
The Great Barrier Reef is a very large and diverse coral system with a high level of biodiversity and has a significant ability to recover from health impacts such as bleaching events.
Reef recovery initiatives have also shown positive results. The Reef Restoration Foundation, a non-profit social enterprise that established the first coral nursery at the Great Barrier Reef in December 2017, said the first coral crop exceeded expectations.
They increased in size by 2.5 times in six months, with nine out of 10 coral thriving and 222 new coral fragments resulting from the initial 24 pieces of coral initially harvested. Soon they will attach about 100 of these thriving corals to damaged coral reefs on Fitzroy Island.
The good news, however, is of no use if the planet's temperature keeps rising. “Rising temperatures experienced worldwide from climate change mean that pressure on the Great Barrier Reef will continue in the future,” says Morris.
“This recovery will always be contingent on environmental conditions. It is critical that every effort is made to promote health and resilience, ”he continued. “We all know that the reef can experience other bleaching events as the weather continues to warm, but we have to do everything we can to protect our Great Barrier Reef.”