Scientists say the invasion of the crown-of-thorns starfish (COTS) is responsible for as much as 40 percent of the decline in coral cover among Australia's Greet Barrier Reefs. That's why researchers at the Queensland University of Technology have put a special agent on the job -- the COTSbot.

COTSbot is the first robot designed to eradicate invading starfish. The underwater hunter was designed and built by robotics engineers at QUT. Recently, the bot completed its first trial missions.

While the autonomous underwater vehicle (AUV) has yet to take out any starfish, it has proven seaworthy. Its mechanical functionality and navigation system performed well during recent tests.

AUVs are increasingly common in marine science, but the sub's software makes COTSbot stand out. Programmers have trained the bot to scan underwater environments and and recognize the presence of the invading starfish. Once identified, the COTSbot's robotic arm delivers a lethal shot.

The bot can search underwater for up to eight hours, and is able to inject as many as 200 starfish. Researchers plan on using the bot as a first line of defense against starfish found among newly invaded reefs.

While the starfish aren't an invasive species, population explosions are damaging to reefs, as the spreading starfish feed on coral tissue and diminish biodiversity.

Human divers are already on the job of thinning out high concentrations of the starfish, and they will continue to tag-team with COTSbot in protecting vulnerable coral.

"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," Matthew Dunbabin, a researcher at QUT's Institute for Future Environments, said in a press release.

"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."

Dunbabain and his colleagues expect the robot to be deployed and active by December.