Grande barreira de corais da Austrália

Global warming transforms coral reefs, but there’s a way to save them

Overheated seawater caused bleaching to the corals structure; however fighting global warming can change damages.

Chosen as one of the seven natural wonders of the world in 1997, Australia's Great Barrier Reef has changed. It's forever. A study published by the science magazine Nature in April confirmed that damaged caused by the excessive heatwave in 2016 is irreversible and caused the bleaching event – algae, which have a symbiotic relationship with reef-building corals, were expelled – in roughly one third of the 2,300-kilometer length of the natural assemblage.

In the report, scientists affirmed that sea life in the region had been heavily impacted by the overheated water. More recently, the team not only confirmed this impact, but also found that it was even larger than they previously thought. And, according to the study, the global warming is the one to blame.

“The reef is changing faster than anyone thought it would. One thing we can be sure about is the reef isn’t going to look the same again,” said Terry Hughes, the lead author of the study and the director of a center for coral reef studies at James Cook University, in an interview to The New York Times.

What happened to the corals - and how to save them

The Great Barrier Reef is home to thousands of species in Australia, sharks, turtles and whales are among the 3863 species catalogued. Corals require warm water to thrive, but they are extremely sensitive to heat. Temperature increase from 2 °C is enough to unbalance their habitat and destroy them. It is estimated that only 10% of reefs escaped with no bleaching in their assemblage.

In 1998 and 2002, there were reports on climatic incidents that resulted in large-scale coral bleaching, but none of them was as aggressive as in 2016. Environmentalists are concerned about two issues, in particular. They have identified that the fastest-growing coral species are the most affected, which directly compromises local biodiversity. They also confirmed that protecting the reefs and adjacent waters does not manage to control the problem.

Thus, scientists have reached the conclusion that the more frequent these heatwaves are, the more difficult the ecosystem will recover.

How can we prevent destruction from progressing?

There is a way to prevent destruction, and the solution is directly linked to achieving the goals set for controlling climate change and global warming.

“It is now critical to understand how governance and local management can maximize recovery between recurrent heatwaves,” Nick Graham, a marine ecologist at Lancaster University, said to Nature magazine. “If we fail to curb climate change, and global temperatures rise far above 2 °C, we will lose the natural, scientific and economic benefits they provide,” he added. In addition to the beauty of the Great Barrier Reef, which is the subject of much research on marine diversity and one of Australia's major tourist attractions, in addition to creating thousands of jobs.

According to the research, the transition that is taking place on the coral barrier is unavoidable, and will continue throughout the century - although it is happening at a much faster pace than scientists imagined.

Therefore, the fate of tropical coral reefs depends on us. “A future with coral reefs, their rich diversity and the livelihoods they provide to people is quite simple. It will only be possible if carbon emissions are rapidly reduced,” Graham says.