I HAVE just acquired my sea legs after a 20 minute cruise across the port of Gijon, Spain, when I spot a blue shipping container on the pier. Standing beside it is Luke Speller, a scientist at the British technology firm BMT, looking across the water. With iPad in hand, he is sending instructions to a robotic fish that has just been deployed from a nearby dinghy.
The fish’s dual-hinge tail thrashes into motion, but then settles down into a surprisingly lifelike rhythm. Mimicking a real fish is key, says Speller, as a propeller-driven robot wouldn’t be able to make the tight turns required to navigate the port and sniff out pollutants such as lead and copper with its onboard sensors. “With these fish we can find exactly what is causing the pollution and put a stop to it right away,” he says.
“With these robofish we can find exactly what is causing the pollution and put a stop to it right away”
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Speller is the leader of , a European project in which universities, businesses and the port of Gijon have joined forces to create a team of autonomous robots that work together to monitor water quality.
The SHOAL fish are 1.5 metres long, comparable to the size and shape of a tuna, and capable of running for 8 hours on one battery charge. Working in a group, the fish can monitor a square kilometre of water, down to a depth of 30 metres.
To communicate with each other and a nearby base-station, the fish use very low-frequency sound waves, which can penetrate the water more easily than radio waves. On the first test, the sound attracted a dolphin – an unusual sight so close to land, says Speller. After briefly checking out the robot it ignored the intruder.
Navigation relies on a related system that communicates with four “pingers” at the corners of the port, which act like GPS satellites for the fish. If one fish senses pollution in an area it can call the others to its location to create a detailed map of pollutant concentrations in the area, helping port authorities locate the source.
Speller climbs aboard to show me how he can direct the fish to particular locations using an app that also visualises recorded pollution levels. He plans to make this accessible to the public – minus the controls, of course.
Having demonstrated that the fish can sense pollution and communicate underwater, the SHOAL group now plans to commercialise the design and sell it to other ports. The prototypes cost around £20,000 each, but mass production should bring that down.
Speller wants to do more than just track pollution, however. The fish’s modular design makes it easy to swap the chemical sensors for other applications. “I like to see the fish as a platform for other things that can be done in the sea, such as search and rescue, helping divers and port security,” he says. He would also like to create a separate line of sailboat robots that could treat pollution. Communicating directly with the robofish, these would home in on a contaminated area to scoop up any pollutants on the surface.
At this point our boat has strayed outside Wi-Fi range from Speller’s shipping-container office, so his app no longer works and the fish is moving autonomously. As I look down at it swimming through the water, it is easy to imagine Speller’s proposed future in which robots patrol the waves, working together to keep the sea clean. For one thing, machines don’t get seasick, and I’m starting to feel a little queasy.
