A new robot could seek out and destroy invasive starfish in the Great Barrier Reef.

QUT robots are the first to be designed to battle the Great Barrier Reef's crown-of-thorns starfish (COTS), which are believed to have contributed to a staggering 40 percent of the reef's loss of cover, Queensland University of Technology reported.

"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," said Matthew Dunbabin from QUT's Institute for Future Environments. "We see the COTSbot as a first responder for ongoing eradication programs - deployed to eliminate the bulk of COTS in any area, with divers following a few days later to hit the remaining COTS."

The robots are equipped with: stereoscopic cameras for depth perception; five thrusters for stability; GPS technology; and unique pneumatic injection arms to deliver fatal bile salts to the invasive starfish. They passed recent field tests that focused on their mechanical parts and navigation systems.

"The COTSbot becomes a real force multiplier for the eradication process the more of them you deploy - imagine how much ground the programs could cover with a fleet of 10 or 100 COTSbots at their disposal, robots that can work day and night and in any weather conditions," Dunbabin said.

The robot is designed to scout the oceans for up to eight hours and deliver about 200 lethal shots to starfish. They were taught to identify these target starfish using state-of-the-art computer vision and machine learning system that employed thousands of still images and videos; the robots will also continue to learn through their field work.

"Its computer system is backed by some serious computational power so COTSbot can think for itself in the water," said Feras Dayoub, who designed the COTS-detecting software. "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."

COTSbot will be taken to the Great Barrier Reef later this month to be tested on live targets, but humans will approve its actions before it performs a lethal injection.