Scientists plan to release a robot into the Great Barrier Reef to tackle a wave of destructive starfish, known as the Crown-of-thorns starfish.
Researchers from Queensland University of Technology built a machine called the COTSbot (Crown-of-thorns robot) which actively seeks out the starfish autonomously. Upon finding the Crown-of-thorns starfish the COTSbot gives them a lethal injection before continuing it’s search.
Crown-of-thorns starfish are a big problem on the reef as they are carnivorous and consume coral. This results in widespread devastation to reefs when the population numbers are high, which they currently are. The Great Barrier Reef’s coral cover has dropped by half in the last 30 years and researchers believe that around 40% of what has been lost is due solely to the crown-of-thorns starfish.
The rise in crown-of-thorns starfish is thought to be related to inland flooding which causes nutrients to be washed into the ocean. This results in more plankton which in turns results in greater starfish larval survival. Population surges occur every 12 years on average and when they do the starfish destroy up to 90% of available coral. They are density dependant meaning when there are more they of them eat so much that they use up all available food and thus the population drops due to a lack of food. Unfortunately the Great Barrier Reef still has a high amount of coral and so the starfish look set to decimate the reef. The reef is currently also under threat from cyclones, ocean acidification and possible dredging work so it is crucial that something is done before too much of the reef is lost.
The robot has a very sophisticated image recognition system and a robotic arm which delivers lethal injections. If the robot is unsure if something is a starfish it takes a photograph and the researchers are able to tell the robot if what it has seen is a starfish or not. All positive images are stored in it’s memory banks to allow for better detection rates in the future. As the robot learns what is and is not a starfish it will become more autonomous and eventually roam almost freely throughout the reef.
The researchers are still refining the navigation system on the robot and expect to begin trials in the Great Barrier Reef in around a month’s time. If the trials are successful it is expected to be fully operational by December. It can work 8 hours a day and kill 200 starfish in a single dive so the implications for this project are huge if it is successful.
A video of the COTSbot in action can be found at the following link.