The direct and indirect effects of global warming, such as ocean acidification and the large bleaching episode, have caused significant and lasting damage to the Great Barrier Reef. Large parts of the reef have no chance of recovering naturally, so an intervention has been designed to address what humans have done at this World Heritage site.
The objective of the larval restoration project is to restore reproductive populations in damaged reefs and to ensure healthy coral reproductive cycles. The team will harvest sperm and coral eggs and will form new larvae which will then be released in the most damaged areas of the reef. Efforts will begin this weekend in the Arlington Reef area, located just off the coast of Cairns, Queensland.
"This is the first time that the entire large-scale larval culture and rearing process is undertaken directly on the reefs of the Great Barrier Reef," said Peter Harrison, chief project, from the University of Southern Cross. "Our team will restore hundreds of square meters in order to reach square kilometers in the future, a scale never tried before."
The Harrison team has tested this regeneration approach at smaller scales in the Philippines, as well as on the Heron and One Tree Islands in the southern Great Barrier Reef. If this attempt on a larger scale succeeds as well, it could be used elsewhere in the world.
A particularly interesting innovation in this trial is the co-cultivation of tiny algae, called zooxanthellae, which live in the tissues of many corals. Coral and microalgae have a mutual relationship. The coral protects the algae and provides them with nutrients. Algae produce oxygen and eliminate coral waste.
"These microalgae and their symbiosis with corals are essential for healthy coral communities that build reefs," said Professor David Suggett, a collaborator at the Sydney University of Technology. "So we aim to accelerate this process to see if the rapid absorption of algae can boost the survival and early growth of juvenile corals."
The project is a collaboration between Harrison, Suggett, James Cook University's Katie Chartrand, the Great Barrier Reef Marine Park Authority, the Queensland Parks & Wildlife Service, and other key partners in the industry. . The intervention is audacious but should not be considered as a way to save the reef. It's the damage control.
"Our approach to reef restoration is to give coral populations the time they need to survive and evolve until emissions are capped and the climate stabilizes," said Professor Harrison. "Climate action is the only way to ensure the survival of coral reefs."