Researchers at the ARC Center of Excellence for Coral Reef Studies in Queensland, northeastern Australia, between 1995 and 2017 assessed coral communities along the Great Barrier Reef and their colony size, and found that all coral populations were declining.
The Great Barrier Reef, the world’s largest coral reef, covers an area of 133,000 square miles and is home to more than 1,500 species of fish, 411 species of hard coral and dozens of other species.
“We 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 co-author Terry Hughes, distinguished professor at the ARC Center for Excellence in Coral Reef Studies.
Rocks are fundamental to the health of marine ecosystems – without them ecosystems would collapse and marine life would die.
The Great Barrier Reef covers an area of 133,000 square miles.
Franോois Gohier / VWPix / Universal Images Group / Getty Images
The size of the coral population is also important in terms of the reproductive capacity of the coral.
“Ibra’s vibrant coral population includes millions of small and baby corals, as well as large larvae that produce large larvae,” said Andy Dietzel, a doctoral student at the ARC Center of Excellence for Coral Reef Studies. In a statement.
“Our results show that the Great Barrier Reef’s resilience – and its restoration – is compromised compared to the past because there are fewer breeds and larger breeding adults,” he added.
The population is declining in shallow and deep coral species, experts found, but the branching and table-shaped corals – which provide habitat for the fish – were the worst affected by the mass bleaching events of 2016 and 2017, a record-breaking temperature.
The authors of the report warn that climate change is increasing the frequency of “reef disturbances”.
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The main driver of coral bleaching is warm ocean temperature, when the corals turn white in response to pressure from very hot water. Bleaching does not destroy the coral immediately, but if the temperature continues to rise, the coral will gradually die, destroying the natural habitat of a variety of marine life.
A study on Tuesday found that coral colonies in the northern and central Great Barrier Reef have plummeted following bleaching incidents in 2016 and 2017.
The Great Barrier Reef has experienced numerous bleaching incidents over the past five years, and experts say that by early 2020, the southern part of the Reef will also be experiencing record-breaking temperatures.
“We thought the Great Barrier Reef would be protected by its full size – but our results show that even the world’s largest and relatively well-preserved reef system is more compromised and collapsing,” Hughes said.
The authors of the report warn that climate change is increasing “reef disturbances” such as ocean heat.
“There is no time to lose – we must drastically reduce greenhouse gas emissions,” the authors warned in an article published in the Journal of the Proceedings of the Royal Society.
Helen Reagan of CNN contributed to this report.