Underwater drone watches over reefs – and kills coral-destroying starfish
It's no secret that the world's coral reefs are in trouble, and unfortunately scuba divers can only do so much in the way of monitoring or protecting them. Scientists in Australia, however, have developed an autonomous underwater drone that could be of great help.
Known as RangerBot, the prototype device was developed via a partnership between the Queensland University of Technology (QUT), Google, and the Great Barrier Reef Foundation. Although it's been in the works for the past two years, it was officially launched this August 31. Sea trials are now underway.
The drone is programmed using a tablet while still at the surface – the process can reportedly be learned within 15 minutes. Once submerged, it uses a computer vision system to avoid obstacles, and to navigate. That system (along with other sensors) also allows it to detect and record reef problems such as coral bleaching, poor water quality, pollution, siltation and pest species.
In the case of the latter, the drone is able to identify coral-eating crown-of-thorns starfish with an accuracy rate of 99.4 percent. When it does, it can inject them with a poison that doesn't affect other reef organisms – its predecessor, the COTSbot, is capable of doing the same thing. Students at Worcester Polytechnic Institute, on the other hand, recently developed an autonomous underwater robot that kills invasive lionfish.
Tipping the scales at 15 kg (33 lb), the 75-cm-long (30-inch) RangerBot has a battery life of approximately eight hours per charge. This lets it stay underwater much longer than a scuba diver, being able to survey considerably larger areas. It's also designed to be inexpensive once it reaches production, allowing for widespread use.
"We believe this represents a significant technology leap in both marine robotics and reef protection – the only autonomous, affordable, multi-function solution for effectively detecting and addressing threats to coral reefs," says QUT Prof. Matthew Dunbabin. "Our vision is to make RangerBots readily available and accessible to be deployed on the Reef where they're most needed and to put them in the hands of reef managers, researchers and communities worldwide."
The drone can be seen in action, in the video below.
Editor's note: The QUT research was incorrectly attributed when this article was originally published. We apologize for this error. The article was corrected post-publication.