Robots to play "stork" and plant coral larvae around the Great Barrier Reef

That Australia's Great Barrier Reef is in serious trouble is no longer subject to debate, but the best way to deal with the problem very much is. An all-out assault on coral predators, giant fans to combat rising sea temperatures and recycling dead corals are all proposals being put on the table. The latest to emerge involves robots playing the role of "the stork" and distributing coral larvae across the Reef to promote new growth.

The Great Barrier Reef has been devastated by a string of major bleaching events, most recently in 2016 and 2017 that left the middle and northern sections of the Reef severely damaged. These bleaching events occur when abnormal sea conditions, such as warmer waters, cause stress on the algae living inside the coral and leave them withered, whitened and in danger of dying. Coral can bounce back on its own from these kinds of severe bleaching events, but with sea temperatures expected to continue rising, conservationists are looking at ways to give them a fighting chance.

The Great Barrier Reef Foundation is a charity dedicated to conserving the world's largest living structure, and its Out of the Blue Box Reef Innovation Challenge provides AU$300,000 (US$225,000) to a winning concept that aligns with that vision.

Chosen from five finalists, the winning project comes from Southern Cross University's Professor Peter Harrison and Queensland University of Technology's (QUT's) Professor Matthew Dunbabin. The pair have come up with an idea hoped to give mass coral spawning events a huge boost boost, with the prize money to be used to bring that idea to life.

The approach starts with the collection of millions of spawn from the corals that endured the two most recent major bleaching events, and rearing them into baby corals inside large tanks. Harrison tells us these tanks are currently under construction and will measure 30 m (98 ft) in diameter, with larger ones to be built in the future.

Last month we looked at a device called the RangerBot, an autonomous underwater robot built at QUT to patrol the Reef for killer crown-of-thorns starfish. When the time is right, a new generation of RangerBot, called LarvalBot, will play stork by distributing the coral larvae throughout the Reef during annual spawning events. This is expected to not only greatly increase baby coral numbers, perhaps by 100 times, but also enable them to be placed where the Reef needs them most.

The trouble is, damage to the Reef spans hundreds of kilometers, so you can't help but wonder how much of an impact these LarvalBots can really have. Harrison explains that it is about baby steps for now, and that the first LarvalBot will be in large part a proof-of-concept, which will hopefully enable them to verify the technique and build on it from there.

"The combination of large scale larval rearing and delivery via underwater LarvalBot vehicles will allow us to greatly increase the scale of coral larval restoration on multiple target reefs," he tells New Atlas. "Key reefs targeted for larval restoration would include reefs that act as source reefs of larvae for many other reefs down current, or reefs that have special ecological or management values, or reef that are commercially important for tourism in which case businesses could contribute funding for restoration."

The Great Barrier Reef Foundation has come under some scrutiny of late, due to a AU$444 million (US$315 million) government grant landing in its lap, with many arguing there was a lack of transparency surrounding the funding windfall. So much so, the federal opposition party has vowed to take that funding back if it wins power at the election next year.

Harrison points out that the trials deploying the first LarvalBot in November during the mass coral spawning event will go ahead regardless, as funding for the Out of the Blue Box Reef Innovation Challenge is philanthropic and is therefore not connected to the government grant.

The hope is that if it proves effective, the LarvalBot approach can be replicated elsewhere around the world where coral reefs are under threat from climate change.

Source: The Great Barrier Reef Foundation