A "fossil coral reef" found off the Mid North Coast by a team of University of Wollongong scientists will provide valuable insight into how climate change may affect today's reefs.
The UOW team recently spent two weeks aboard Australia's national marine research vessel, the RV Southern Surveyor, to map shallow waters around the remnant of a volcano in the Lord Howe Island Marine Park.
Through the use of multi-beam sonar imaging and video cameras, they discovered the ancient relics of a coral reef in waters around Ball's Pyramid, 600 kilometres east of the mainland.
Team leader Professor Colin Woodroffe said the coral reef - believed to have flourished 8000 years ago - would probably have been killed off as temperatures, and sea levels, rose.
"We mapped large sections of the sea floor around this monolith of volcanic rock, which is where we found these fossil reefs," he said.
"It's an important find for a number of reasons - firstly it shows us that coral reefs have occurred further south in the Pacific Ocean than they do at the moment.
"Through this we can then find out more about how much sea levels have changed over thousands of years, and how changes in ocean temperature have affected coral reefs.
"This can help us better understand how climate change, and rising sea levels, will affect today's coral reefs."
Prof Woodroffe said the research could indicate that coral reefs could spread further south due to global warming.
"In the tropics coral reefs are in danger because of coral bleaching - high temperatures are causing the stress or even death of coral," he said.
"So with an increase in temperatures further south, will that mean coral reefs will stretch further down the coast of Australia, or further into the Pacific Ocean?"
Prof Woodroffe said the team had been collaborating with researchers from Geoscience Australia, the NSW Department of Primary Industries and the managers of the marine park.
"Our findings give marine park managers a greater appreciation of the area that is reserved within the marine park, and may be incorporated into their future management plan," Prof Woodroffe said.