SYDNEY: Scientists have launched the largest attempt at coral regeneration on the Great Barrier Reef in danger of extinction by collecting the eggs and sperm from the creatures during their annual spawning.
The researchers said Wednesday they plan to grow coral larvae from harvested eggs and return them to reef areas that have been damaged by climate-related coral bleaching.
"This is the first time that the entire larval rearing and settlement process will take place directly on the reefs of the Great Barrier Reef," said Peter Harrison of Southern Cross University, one of the project leaders. .
"Our team will be restoring hundreds of square meters in order to reach square kilometers in the future, a scale that was not previously attempted," he said in a statement.
The launch of the "larva restoration project" was scheduled to coincide with the annual coral spawning in the reef, which began earlier this week and will only last between 48 and 72 hours.
Corals along large swaths of the 2,300-kilometer (1,400-mile) reef have been eliminated by rising sea temperatures related to climate change, leaving skeletal remains in a process known as coral bleaching.
The northern stretches of the reef suffered two consecutive years of severe bleaching unprecedented in 2016 and 2017, which raised fears that it could have suffered irreparable damage.
Harrison and his colleagues hope that their overseeding project can help reverse the trend, but warned that the effort alone will not be enough to save the reef.
"Climate action is the only way to ensure that coral reefs can survive in the future," he said.
"Our approach to reef restoration aims to save time for coral populations to survive and evolve until emissions are limited and our climate stabilizes."
Scientists hope that the corals that have survived the discoloration have a greater tolerance to the increase of the temperature, reason why the reproductive population produced from the reproduction of this year will turn into coral better able to survive in future events of discoloration .
The researchers, who also include experts from James Cook University and the University of Technology in Sydney (UTS), said a novelty of their overseeding project was to grow coral larvae along with microscopic algae.
The two live in symbiosis on the reef.
"Therefore, we are aiming to accelerate this process to see if the survival and early growth of juvenile corals can be driven by the rapid absorption of algae," explained David Suggett of UTS.