Direct and indirect effects of global warming, like ocean acidification and the Great Bleaching Event, have resulted in large-scale and long-lasting damage to the Great Barrier Reef. Large portions of the reef have zero prospects of recovering naturally, so an intervention has been devised to remedy what humans have done to this World Heritage site.
The Larval Restoration Project’s goal is to reestablish breeding populations in damaged reefs and make sure the reproductive life cycles of corals are healthy. The team will harvest coral sperm and eggs and grow new larvae which will then be released in the most damaged areas of the reef. The effort will begin this weekend in the Arlington Reef area, which is located just off the coast of Cairns in Queensland.
“This is the first time that the entire process of large-scale larval rearing and settlement will be undertaken directly on reefs on the Great Barrier Reef,” project leader Professor Peter Harrison, from Southern Cross University, said in a statement. “Our team will be restoring hundreds of square meters with the goal of getting to square kilometers in the future, a scale not attempted previously.”
Harrison’s team has trialed this regeneration approach on smaller scales in the Philippines, as well as Heron and One Tree Islands in the southern Great Barrier Reef. If this larger scale attempt is as successful, it could be employed elsewhere around the world.
One particularly interesting innovation of this trial is the co-culturing of tiny algae known as zooxanthellae, which live in the tissues of many corals. The coral and the microalgae have a mutualistic relationship. The coral protects the algae and provides it with nutrients. The algae produce oxygen and remove waste from the coral.
“These microalgae and their symbiosis with corals is essential to healthy coral communities that build reefs,” collaborator Professor David Suggett, from the University of Technology Sydney, explained. “So we are aiming to fast-track this process to see if the survival and early growth of juvenile corals can be boosted by rapid uptake of the algae.”
The project is a collaboration between Harrison, Suggett, Katie Chartrand from James Cook University, the Great Barrier Reef Marine Park Authority, Queensland Parks & Wildlife Service, as well as other key industry partners. The intervention is a bold move but it shouldn’t be seen as a way to save the reef. This is damage control.
“Our approach to reef restoration aims to buy time for coral populations to survive and evolve until emissions are capped and our climate stabilises,” Professor Harrison said. “Climate action is the only way to ensure coral reefs can survive into the future.”