For the first time, an underwater robot is being used to plant baby corals in parts of Australia's Great Barrier Reef that have been damaged by mass bleaching as scientists gather hundreds of millions of corals from the Queensland city of Cairns in the coming weeks.
Most corals multiply by spawning, whereby eggs and sperm are simultaneously pushed into the water. In Northern Australia, researchers are preparing to harvest this mass release of coral spawning on the Great Barrier Reef. They are raised to baby corals in floating enclosures. Then they are brought to Vlasoff Reef as so-called "larval clouds", which depart about an hour from Cairns away from a semi-autonomous robot.
Professor Peter Harrison, director of the Marine Ecology Research Center at Southern Cross University, said that science is giving nature a helping hand.
"We're now trying to compensate for the loss of coral that normally provides enough larvae for the natural healing system," Harrison said.
Large parts of the Australian Great Barrier Reef were damaged by severe bleaching – or by the loss of algae, which give the coral its color. Bleaching is caused by rising water temperatures and aggravated by climate change.
The experiment at the Vlasoff reef, which has been severely affected by mass bleaching, will be coordinated by divers who will lead the spawning propagation robot, the so-called LarvalBot.
Professor Matthew Dunbabin of the Queensland University of Technology says that time is crucial.
"We hope that we can start doing this autonomously in future projects, but this is very new and we are against the time when we try to get this into the field as quickly as possible to make sure we do can have a reef to keep, "said Dunbabin.
A coral reef consists of millions of tiny animals, the so-called coral polyps. The reefs are critical ecosystems and contain at least a quarter of all marine animals.
The Great Barrier Reef is about the same size as Italy or Japan. Thirty species of whales, dolphins and porpoises were observed along the reef.
It is exposed to a range of threats, from climate change, over-fishing, to farm pollution, to coral-eating spines.