A new robot is helping humans address serious issues in nature.

Australian roboticists have developed the world's first robot designed to seek out and control the Great Barrier Reef's crown-of-thorns starfish (COTS), which have destroyed about 40 per cent of the reef’s coral cover.

The COTSbot has now completed its first sea trials in Queensland's Moreton Bay to test its mechanical parts and navigation system.

COTSbot is 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,” says its creator, Dr Matthew Dunbabin from the Queensland University of Technology.

“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 condition.

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.

Researchers spent 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.

It can even learn from its experiences in the field.

“Its computer system is backed by some serious computational power so COTSbot can think for itself in the water,” said designer Dr Feras Dayoub.

“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.

“That in itself is quite an accomplishment given the complexity of underwater environments, which are subject to varying visibility as well as depth-dependent colour changes.”

The QUT roboticists will take COTSbot to the Great Barrier Reef later this month to trial it on living targets. In that trail, a human will verify each COTS identification the robot makes before the robot is allowed to inject it.

There are plans for the COTSbot to be working the reef autonomously by December.