For the seventh time since 1998, Australia’s Great Barrier Reef is undergoing the process. “mass bleaching”Deterioration due to climate change, authorities announced on Friday 8 March.
The world’s largest coral reef, stretching over 2,300 kilometers off the northeast coast of Australia, is home to about 1,500 species of fish and 4,000 types of molluscs. “We know that the biggest threat to the world’s coral reefs is climate change. The Great Barrier Reef is no exception.” Environment Minister Tanya Plibersek said in a statement. “We must act against climate change. We must protect our extraordinary places and the plants and animals that inhabit them”she continued.
This new episode of mass bleaching was confirmed by scientists working for the government after an aerial survey conducted over 300 shallow reefs. According to the Australian Coral Reef Authority, further studies need to be conducted to assess the intensity and extent of bleaching.
Record the temperature level
This phenomenon of dieback, which results in discoloration, is caused by an increase in water temperature that leads to the expulsion of symbiotic algae and gives the coral its bright color. It occurs when the underwater temperature rises by more than one degree above the long-term average.
Ocean temperatures along the Great Barrier Reef have hit record highs in recent weeks, official data shows. Ocean heat waves in 1998, 2002, 2016, 2017, 2020 and 2022 caused massive coral bleaching on the Great Barrier Reef.
According to Richard Lake, WWF Australia’s head of oceans, many corals will die if ocean temperatures do not drop rapidly in the coming weeks. “This bleaching episode is occurring in an area where corals have never been exposed to such temperatures.”, he declared. Mr. Lake explained that climate is causing change “significant pressure” On the Great Barrier Reef.
A similar dieback occurred last year in the Northern Hemisphere, Lake said, leading to the damage “dramatic” Corals in Florida and the Caribbean. Some corals may recover if weather conditions improve, with the exception of those that are significantly bleached or experiencing frequent heatwaves.
Tensions between Australia and UNESCO
But Terry Hughes, one of Australia’s leading coral reef scientists, said bleaching events were now becoming so frequent that reefs were struggling to recover. “The reef is no longer able to regain the mix of coral species and coral sizes that existed 20 years ago”He told Agence France-Presse.
“The irony is that in most areas of the Great Barrier Reef today the dominant corals grow faster and gain ground faster, but they are sensitive to heat and less tolerant of the inevitable next bleaching episode ». According to him, heat stress has increased in recent days and is expected to worsen in the next two weeks.
The reef’s fate has been a source of tension between the Australian government and UNESCO, which has threatened to list it as a World Heritage Site in 2021. “in danger”. Such a listing would be unexpected for Australia, dealing a serious blow to the tourist attraction of the coral complex, which generates $4.8 billion in revenue. Behind-the-scenes diplomatic negotiations and intense lobbying by Australia have so far prevented the reef from being included on the list.
