New science to boost coral growth in Great Barrier Reef

28 Mar 2019

The University of Queensland (UQ) along with consultancy firm BMT will recreate 3D artificial coral structures, helping to protect the Great Barrier Reef, promote new growth and restore depleted coral-reef fish populations.

A team of experts from BMT and the Schools of Civil Engineering and Biological Sciences from UQ, supported by underwater specialists from Commercial Marine Group, have begun reef rehabilitation trials at two reef sites on the Great Barrier Reef near the Whitsunday Islands.

The trials aim to stabilise coral rubble which was produced in massive quantities as a result of Tropical Cyclone Debbie in March 2017.

The trials form part of a wider plan proposed by BMT and UQ researchers to recycle dead coral into structures that can help protect the remaining reef and promote new growth.

The phase one climate-related geoengineering and biodiversity trials will provide an opportunity to test and fine-tune the approach, as well as helping to gauge greater insight into the physical and biological responses that will take place following deployment.

BMT Project Leader Dr David Rissik said that the lessons learned from cyclone wave damage will enable the team to develop cost-effective approaches and implement these at relevant scales.

“Having seen the scale of impact to coral that remains from TC Debbie, we have the opportunity to make a real difference in this area," Dr Rissik said.

"The new proposed plan by BMT and UQ addresses the issue of dead and damaged coral accumulating at the bottom of the seabed, where it begins binding together and forming a foundation for new coral to take hold.

"The team wants to speed up that process by collecting dead coral and building new structures out of it, to protect the remaining reef and stimulate new coral grow growth.

“These 3D artificial coral structures, often known as 'bommies', will not only act as a unique ‘buffer’ against cyclone wave damage but will also provide a stable base for new coral recruitment.

"These artificial 'bommies' would each measure two metres in diameter, and would be placed strategically to help speed up the natural repair processes and provide healthy habitats for fish.”

UQ's Professor Tom Baldock said the approach could also be adopted in other parts of the Great Barrier Reef where there has been damage to the reef itself.

"Stabilising coral rubble increases the likelihood that crustose coralline algae (CCA) will naturally bind the coral to form a stable substrate onto which coral larvae will be able to recruit and establish new coral communities," Professor Baldock said.

“Through the growth of CCA crustaceans that trigger the release of chemicals to attract free-swimming coral larvae, the stabilisation process will become greatly strengthened.

“These new structures would also provide an improved habitat for fisheries and other marine life.”

Researchers build new underwater coral structures in the Great Barrier Reef
Researchers build new underwater coral structures in the Great Barrier Reef using dead coral.

The BMT-UQ team has worked closely with the Great Barrier Reef Marine Parks Authority and with Queensland Government agencies to select trial sites, to develop deployment protocols and to ensure that all necessary environmental approvals were obtained.

The pilot project has been funded by the Australian and Queensland governments and is being run through the Advance Queensland Small Business Innovation Research Coral Abundance Challenge.