Global warming, overfishing and water pollution have had a disastrous effect on the Great Barrier Reef. This natural wonder has lost at least half of its corals since 1995, a likely irreversible ecological disaster, according to a new study.
50% loss in just 30 years
In a new study, scientists claim that half of the corals in Australia’s Great Barrier Reef have died in the past 25 years. This disaster is notably the result of the increase in ocean temperatures which is caused by global warming. In fact, too high temperatures cause a phenomenon called coral bleaching. Normally, this phenomenon is reversible, but as climate change has intensified, corals find it increasingly difficult to recover.
The study, published in the Proceedings of the Royal Society journal, is the result of the assessment of the health and size of coral reef colonies between 1995 and 2017. The research was conducted by marine scientists from the ARC Center of Excellence for Coral Reef Studies. She found that while all types of corals were affected by this decline, it was the larger species that were most affected. ” They are generally 80-90% depleted compared to 25 years ago “Said Terry Hughes, lead author of the study at AFP.
The Paris Agreement: last hope to save the Great Barrier Reef
This situation is serious as these corals are a source of food and a refuge for a large number of fish and other marine creatures. Their disappearance thus continues to generate an imbalance in the ecosystem. The study also found that much of the decline was observed along the northern and central regions of the Great Barrier Reef, where massive coral bleaching occurred in 2016 and 2017. The southern part of the reef had also been exposed to record temperatures at the start of 2020.
In total, the Great Barrier Reef was affected by five mass bleaching events caused by global warming between 1998 and 2017. Besides the effects of heat, corals were also affected by the influx of fresh water. ” We used to think of the Great Barrier Reef as protected by its size, but our results show that even the world’s largest and relatively well protected reef system is increasingly compromised and in decline. Said Terry Hughes. For now, scientists continue to assess the extent of the damage.
It is to know that the Great Barrier Reef is the largest coral reef in the world. It stretches 2,300 kilometers along the northeastern coast of Australia and covers an area of approximately 350,000 square kilometers. This site has been a UNESCO World Heritage Site since 1981. Unfortunately, it risks losing this status if measures are not taken to keep the increase in global average temperature below 2 degrees. Indeed, if the different countries manage to respect the Paris agreement on the climate, the corals have a chance to regenerate sufficiently to save the site. Otherwise, Terry Hughes explained that the Great Barrier Reef would be lost forever if temperatures rise to 3 or 4 degrees Celsius.