‘Mass bleaching’ phenomenon is occurring on Australia’s Great Barrier Reef



A diver observes coral bleaching in the southern Great Barrier Reef, Keppel Islands, Australia, on March 5, 2024.

Unsurprisingly, the Great Barrier Reef faces the worst-case scenario. Climate change is not only creating a vicious cycle, it is accelerating it. On Friday, March 8, Australian authorities said a “massive bleaching” process, the seventh in 26 years, is affecting the world’s largest inhabited structure, located off the island continent’s northeast coast. Announced. This is the fifth occurrence in the past eight years.

read more Subscriber only Australians race against time to save the Great Barrier Reef

Aerial surveys of more than 300 coral reefs covering two-thirds of the marine park suggest the damage is extensive. “The problem this time is the scope of the problem. It appears that the entire Great Barrier Reef has been affected, including the southern part, but some coral reefs have not been affected much and are in relatively good condition. We’re seeing high waves.” Andrew Baird, a marine ecologist at James Cook University, said he feared the new bleaching event would prove to be of an “unprecedented scale.” did. Research is underway to determine its exact extent and depth. Its severity will also depend on changes in ocean temperatures over the coming weeks.

Bleaching is a coral decline phenomenon caused by rising surface water temperatures, which results in the expulsion of the symbiotic algae that give corals their bright colors. If water stress is rapidly reduced, marine life can recover. Otherwise, they will start dying. Some are more resilient than others.

Unprecedented levels of thermal stress

Since the first major phenomenon occurred in 1998, the ecosystem covering all of Italy was affected in 2002, then at an accelerating rate starting from 2016, and in 2016, 2017, 2020, 2022, And now, in 2024, a large-scale bleaching event is occurring. , 98% of the 3,000 individual reefs are affected and are home to approximately 1,500 species of fish.

“The higher the frequency of episodes, the less time it takes corals to recover and the more vulnerable they become,” Baird explained. “This frequency is likely to become annual for decades to come. And clearly the Great Barrier Reef as we know it will not be able to withstand such pressure,” the scientist added. In the Townsville area, where he is based, he has already noticed changes in the species composition, with more underwater grasses and fewer large coral colonies.

In the summer of 2022, scientists also became alarmed when they discovered that the structure was bleaching for the first time in a La Niña year. La Niña is a climate phenomenon characterized by abnormally low water temperatures, usually along the southern coast. On July 4, 2023, the World Meteorological Organization warned that the Great Barrier Reef was headed for a period of extreme danger as it announced the return of El Niño, which is synonymous with rising temperatures in the Antipodes, and that it is likely to occur in 2023. It took shape in the summer of . Central and southern regions are experiencing unprecedented levels of heat stress.

You can read the remaining 30.59% of this article. The rest are exclusive to subscribers.

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *