The direct and indirect impacts of global warming, such as ocean acidification and large bleaching, have led to extensive and long-term damage to the Great Barrier Reef. Large cliffs have zero prospects for recovery naturally, so an intervention has been designed to correct what people have done at this site of the world heritage.
The aim of the larva restoration project is to restore the breeding stock to the damaged reefs and to ensure the reproductive lives of the corals are healthy. The team will harvest coral sperm and eggs and grow new larvae that will then be released in the most damaged areas of the cliff. Efforts begin this weekend in the Arlington Reef area just off the coast of Cairns in Queensland.
"It's the first time that the entire breeding and larval settlement process takes place on a cliff at the Great Barrier Reef," said Professor Peter Harrison of Southern Cross University. "Our team will rebuild hundreds of square meters in order to reach square kilometers in the future, a scale that has not previously tried."
Harrison's team tested this regenerative approach on smaller scales in the Philippines, as well as the islands of Heron and One Tree in the Southern Great Barrier Reef. If this attempt at a larger scale is successful, it could be used elsewhere in the world.
One particularly interesting innovation of this experiment is the joint cultivation of small algae known as zooxanthellae, which live in the tissues of many corals. Coral and microalga have a relationship. Coral protects the lashes and provides nutrients. Algae produce oxygen and remove coral waste.
"These micro-organisms and their symbiosis with corals are essential for healthy coral communities that create cliffs," said Professor David Suggett of the University of Technology in Sydney. "So we're trying to speed up this process to see if the survival and early growth of young corals can be backed up by a quick algae recapture."
The project is a collaboration between Harrison, Suggett, Katie Chartrand of James Cook University, Great Barrier Reef Marine Park, Queensland Parks & Wildlife Service and other key industry partners. Intervention is a courageous step but should not be considered a way to save a cliff. This is a check for damage.
"Our approach to restoring cliffs aims to buy time for coral populations to survive and develop until emissions are reduced and our climate stabilizes," said Professor Harrison. "Climate action is the only way to ensure that coral reefs can survive the future."