Scientists say a new discovery has “blown out of the water” everything we thought about deep parts of the Great Barrier Reef.
Scientists say a new discovery has “blown out of the water” everything we thought about deep parts of the Great Barrier Reef. Mike Middleton

Corals thriving at depths of Reef

NEARLY 200 species of corals have been found thriving in deep parts of the Great Barrier Reef, more than six times those previously recorded at the same depths.

Scientists used remotely operated vehicles and specialised divers to survey coral species on reefs between the Torres Strait and Townsville at depths of up to 125m, between 2010 and 2016.

Their findings have been published today in the scientific journal Proceedings of the Royal Society B.

Museum of Tropical Queensland corals collection manager Dr Paul Muir said the 195 corals found during their surveys represented a significant increase from the 32 species previously recorded at these depths across the Coral Sea.

Dr Muir, who dived to a maximum 40m to survey deep water areas, said the research team was surprised by their findings.

"Corals need light for growth, and they've always been associated with the shallows," he said.

"I think the perception is that ones that were found deep were just a few species and not very big in the deeper areas.

"But we've kind of blown that out of the water."

He said the findings represented roughly half the coral species in the region, suggesting deeper habitats could play a significant role in preserving coral biodiversity and helping regenerate damaged shallow reef areas.

"If there are big bleaching events and big cyclone events, while the shallow reefs may be quite decimated in places, deeper reef areas seem to escape with much less damage," he said.

"Because so many species occur down there, the chances of extinction of species in local areas is much more reduced.

"There's also the potential for those deep corals, come spawning time, to settle on shallow reef and help the shallow reef regenerate."

The researchers are hoping to return to the depths to find whether deepwater corals can survive in shallower areas, and to count populations of different species.