Coral reef
© Sarah Lai / AFP
An aerial view of the Great Barrier Reef off the coast of the Whitsunday Islands, along the central coast of Queensland.
Marine biologists in southeast Asia and Australia are harvesting hundreds of thousands of coral spawn with a view to regenerating the world's coral reefs, including the Great Barrier Reef (GBR), a UNESCO World Heritage Site.

Professor Peter Harrison from Southern Cross University in New South Wales, Australia collects coral spawn off the coast of Heron Island on the GBR, matures it in tanks and then transplants it later.

"It's really exciting, this essentially is the rebirth of the reef," Professor Harrison said, as cited by ABC News. "We can grow these corals from microscopic larvae to dinner-plate size, breeding corals in just three years."

"It's a new way of looking at the problem and it's probably the only hope for the future in terms of larger-scale restoration using hundreds of millions of coral larvae. I don't know of any reef system on the planet that is now healthier than it was 35 years ago, and that's really sad.

"In South-East Asia, which is the center of marine biodiversity on the planet, it's estimated that 95 per cent of those reefs are highly degraded and are facing serious threats in the coming decades."

This technique showed great promise when trialled in the Philippines on coral reefs that had been devastated by blast fishing. Researchers create micro sanctuaries along the reefs using mesh curtains, and use a special kind of tile to monitor the growth. Out of the million-plus larvae collected in November 2016, a total of 100 coral polyps survived.

At present, the curtains cover 100 square meters but plans to greatly expand the project are already being developed. As it stands, the project is not designed to restore the GBR's network of over 3,000 reefs covering 344,000 square kilometers (132,000 square miles).

"It's not just about having any coral. It's about getting coral big enough to reproduce," said Chief scientist at the Great Barrier Reef Marine Park Authority (GBRMPA), Dr David Wachenfeld. "Then we've really cracked this problem, because we've kickstarted the natural recovery process of the reef."

"I think that this could be something that changes management of reefs worldwide. All of the reefs, everywhere in the world, are suffering at the moment," Wachenfeld said. "In the past, the Marine Park Authority has had a philosophy of basically getting out of nature's way. But climate change is really changing that. The reef is battered and bruised. It's more impacted than it's ever been before."