Scientists began the largest attempt to regenerate corals on the endangered Great Barrier Reef by collecting millions of eggs and sperm of creatures during their annual spawning. The researchers said that on Wednesday they plan to grow coral larvae from collected eggs and return them to the reef areas that have been badly affected by the coral's climate bleaching.
“This is the first time that the entire process of large-scale hopper rearing and settlement will be carried out directly on the reefs on the Great Barrier Reef,” said Peter Harrison of the University of Southern Cross, 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 has not been undertaken before,” he said in a statement.
The project “Recovery of larvae” was timed to coincide with the annual appearance of corals on the reef, which began earlier this week and will last only from 48 to 72 hours.
Coral along large reef areas of 2,300 km was killed by rising sea temperatures associated with climate change, leaving skeletal remains in a process known as coral bleaching. The northern reef areas experienced an unprecedented two consecutive years of serious bleaching in 2016 and 2017, raising concerns that this could cause irreparable damage.
Harrison and his colleagues hope that their transplant project could help reverse the trend, but he warned that there would not be enough effort to save the reef. “Climate action is the only way to ensure that coral reefs can survive in the future,” he said. Scientists hope that corals that survive whitening will have a higher tolerance to temperature increase, so that the breeding population produced from this year's caviar will turn into corals that can survive future whitening events.
The researchers said that the novelty of their transplant project was the cultivation of coral larvae along with microscopic algae. They live in symbiosis on the reef. “Therefore, we are striving to speed up this process in order to find out whether early growth of young corals can also be accelerated by the rapid absorption of algae,” said David Savett from the University of Technology Sydney.
Published in the dawn, November 29, 2018