Australia’s Great Barrier Reef is experiencing its fourth mass bleaching in only six years, with corals severely damaged by warming sea temperatures. Earlier today, Australia’s Great Barrier Reef Marine Park Authority, which oversees the reef system, confirmed the mass bleaching and expressed hope for a potential recovery.
“It is important to note that bleached coral is stressed but still alive. If conditions moderate, bleached corals can recover from this stress, as was the case in 2020 when there was very low coral mortality associated with a mass bleaching event,” the Marine Park Authority wrote in a statement. “Weather patterns over the next couple of weeks continue to remain critical in determining the overall extent and severity of coral bleaching across the Marine Park.”
This year’s bleaching occurred despite La Niña conditions that are supposed to bring cooler-than-average temperatures and more rain to many parts of the world, including Australia.
The most recent mass bleaching event occurred in 2020, when hot water caused the coral to push the algae that it feeds on out of its tissue, resulting in the pale colour during the “bleaching.” And though a lot of the coral survived that specific bleaching, the overall reef system isn’t exactly thriving. A 2020 report in the Proceedings of the Royal Society B found that the coral population has sharply declined in the last two decades. Large coral species were especially impacted and declined 76% since the 1990s, according to the paper. As the climate crisis continues to warm ocean temperatures, more marine environments are in danger of being deprived of the ideal conditions needed to thrive.
In response to the bleaching, the United Nations is sending a delegation to assess the extent of the damage and to decide if the reef’s status as a UNESCO World Heritage site should be downgraded, the Associated Press reported. This could hurt Australia’s tourism economy and job opportunities, as tourism linked to the Great Barrier Reef is estimated to employ more than 60,000 people.
Its formal status aside, the Great Barrier Reef is an important buffer for large waves, floods, and storms that could protect nearby coasts from significant flooding and erosion. The diversity and health of the reef also supports local marine ecosystems: Thousands of species of fish make their home in the coral reef, and so do six of the world’s seven marine turtle species.