Melbourne: Australian researchers have developed the world's first robot designed to seek out and eliminate the crown-of-thorns starfish (COTS) that are wreaking havoc on the Great Barrier Reef's coral.
COTS are responsible for an estimated 40 per cent of the reef's total decline in coral cover, researchers said.
The COTSbot completed its first sea trials last week in Queensland's Moreton Bay to test its mechanical parts and navigation system.
Its creator, Dr Matthew Dunbabin from Queensland University of Technology (QUT), said the COTSbot was equipped with stereoscopic cameras to give it depth perception, five thrusters to maintain stability, GPS and pitch-and-roll sensors and a unique pneumatic injection arm to deliver a fatal dose of bile salts.
"Human divers are doing an incredible job of eradicating this starfish from targeted sites but there just aren't enough divers to cover all the COTS hotspots across the Great Barrier Reef," Dunbabin said.
"We see the COTSbot as a first responder for ongoing eradication programmes - deployed to eliminate the bulk of COTS in any area, with divers following a few days later to hit the remaining COTS," said Dunbabin.
"The COTSbot becomes a real force multiplier for the eradication process the more of them you deploy - imagine how much ground the programmes could cover with a fleet of 10 or 100 COTSbots at their disposal, robots that can work day and night and in any weather condition," he said.
The COTSbot is designed to search the reef for up to eight hours at a time, delivering more than 200 lethal shots.
Key to the autonomous underwater vehicle is its new state-of-the-art computer vision and machine learning system.
QUT roboticists have spent the last six months developing and training the robot to recognise COTS among coral, using thousands of still images of the reef and videos taken by COTS-eradicating divers.
"Its computer system is backed by some serious computational power so COTSbot can think for itself in the water," said Dr Feras Dayoub, who designed the COTS-detecting software, from QUT's Science and Engineering Faculty and Australian Centre for Robotic Vision.
"If the robot is unsure that something is actually a COTS, it takes a photo of the object to be later verified by a human, and that human feedback is incorporated into the robot's memory bank.
"We've now trained the robot using thousands of images of COTS collected on the reef and the system is proving itself incredibly robust at detecting the COTS," said Dayoub.
The roboticists believe COTSbot is the first autonomous underwater vehicle to be equipped with an injection system.
It's also designed to operate exclusively within a metre of the seafloor, one of the most dynamic and challenging environments for any robot.