By Alice Klein
A 10-metre-wide coral discovered in a remote part of Australia’s Great Barrier Reef is the widest ever found in the reef system, as well as one of the oldest.
The dome-shaped coral was spotted by snorkelers undertaking a citizen science research project off the coast of Goolboodi, or Orpheus Island, in northern Queensland in March. It was named Muga dhambi – meaning “big coral” – by the Manbarra Traditional Owners of the region.
Measuring 10 metres across and 5 metres high, Muga dhambi is the widest and sixth-tallest coral documented in the Great Barrier Reef. It belongs to the Porites genus of coral, which is commonly found in reefs worldwide and can sometimes grow to massive sizes.
The largest known coral in the world is thought to be another dome-shaped Porites in American Samoa, which is about 22 metres across and 8 metres high, and is estimated to be between 420 and 652 years old.
Muga dhambi is also very old. It is probably between 421 and 438 years old based on its size and growth rate, says Adam Smith at Reef Ecologic, an environmental consulting group in Queensland, who led a study of the coral.
The Great Barrier Reef has experienced about 100 coral bleaching events and 80 major cyclones over the past four centuries, hinting that Muga dhambi may have genetic traits allowing it to survive these kinds of assaults, says Smith. If so, harnessing these traits could help save other corals that are at risk of being wiped out by climate change, he says.
Big corals like Muga dhambi are crucial for reef ecosystems because they act as central hubs for reef life, says Smith. “It’s a bit like an apartment block in a town – it’s a real focus point, it’s where a whole lot of fish and other creatures gather to take shelter, rest, and feed.”
Journal reference: Scientific Reports, DOI: 10.1038/s41598-021-94818-w
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