Mechanical hitman has been shown YouTube videos of its prey, which it jabs with a fatal dose of bile salts

This article is more than 5 years old

This article is more than 5 years old

An autonomous robot that can administer a lethal injection is set to be the latest weapon in the fight against the invasive crown-of-thorns starfish on the Great Barrier Reef.

The starfish preys on coral and is responsible for destroying up to 40% of the reef.

Researchers from Queensland University of Technology are close to finishing trials on a robot which will be primed to find and kill the starfish.

The mechanical hitman, known as COTSbot, uses GPS and a series of thrusters to cruise a metre from the seafloor.

Once it spots a crown-of-thorns starfish it uses an extended arm to administer a fatal dose of bile salts.

COTSbot designer Dr Matthew Dunbabin says the robot has been taught to identify the prickly pest using a sophisticated recognition system. “We gave it lots of examples, we trawled YouTube for videos and provided it with thousands of images,” he said.

“We’re 99.99% confident in its accuracy. And if it has any doubt, it takes a photo and sends it back to us for confirmation.”

Facebook Twitter Pinterest The COTSbot, an autonomous robot, is being trialled to find and kill invasive crown-of-thorns starfish. Photograph: Queensland University of Technology/AAP

Now, water quality management and human divers administering the injection are used to try to keep a lid on crown-of-thorns numbers.

It is hoped the robot will be sent out on the reef for up to eight hours at a time, delivering more than 200 lethal shots.

“It will never out-compete a human diver in terms of sheer numbers of injections but it will be more persistent,” said Dunbabin, a QUT research fellow. “It can go out for long periods of time and in all weather conditions.”

After six months of intensive training, COTSbot passed its first sea trial with flying colours in Moreton Bay this week. The next challenge is to see how it navigates strong water currents and more complex terrain in open ocean.

Researchers are hoping to have the robot fully operational on the reef early next year.