In this news, we discuss the Great Barrier Reef has lost more than half of its corals in past 3 decades: Study.
Australia’s Great Barrier Reef, which is the world’s largest reef system, has lost more than half of its coral population in the past three decades, according to a new study.
The research, published in the journal Proceedings of the Royal Society B, assessed coral communities and their colony size along the Great Barrier Reef between 1995 and 2017, and found that small, medium and large corals have all declined during the period. .
“We measured changes in colony size because population studies are important for understanding the demography and ability of corals to reproduce,” said Andy Dietzel, co-author of the Center of Excellence study. from ARC for Coral Reef Studies (CoralCoE) in Australia. .
“We have found that the number of small, medium and large corals on the Great Barrier Reef has declined by more than 50 percent since the 1990s,” said Terry Hughes, another co-author of the CoralCoE study. .
According to the study, the decline has occurred in shallow and deeper waters, and in virtually all species – but mostly in branched and table-shaped corals.
“These were the hardest hit by record high temperatures that triggered mass bleaching in 2016 and 2017,” Hughes said.
Since reefs are underwater ecosystems home to several interrelated species, scientists have said that the loss of these corals means loss of habitat, which in turn decreases the abundance of fish and the productivity of reef fisheries. corals.
Dietzel said that one of the main implications of coral size is its effect on survival and reproduction.
A vibrant coral population includes millions of smaller, younger corals, as well as several large ones, he said.
“Our results show that the ability of the Great Barrier Reef to recover – its resilience – is compromised compared to the past, as there are fewer babies and fewer large breeding adults,” Dietzel said.
Scientists have warned that better data on coral demographic trends is urgently needed.
“If we are to understand how coral populations evolve and whether or not they can recover between disturbances, we need more detailed demographic data: on recruitment, on reproduction and on colony size structure,” Dietzel said.
“We used to think that the Great Barrier Reef is 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,” Hughes added.
According to the researchers, climate change is leading to an increase in the frequency of reef disturbances such as marine heat waves.
The study recorded more marked deterioration of coral colonies in the north and center of the Great Barrier Reef after the massive coral bleaching events in 2016 and 2017.
The southern part of the reef, scientists say, was also exposed to record temperatures in early 2020.
“There is no time to waste – we need to drastically reduce greenhouse gas emissions as soon as possible,” they concluded.
The Great Barrier Reef has lost more than half of its corals in the past 3 decades: study
Small, medium and large corals all declined over the period, study finds