A large yellow fish swims slowly along the waves of the shallow harbor near the city of Gijón in northern Spain, wagging its tail slowly. This calm swimmer is not made of flesh and blood, but metal and carbon fiber. The yellow fish is a robot, the latest weapon of scientists in the struggle for a clean environment.
An autonomous marine vehicle is working on a difficult and important task, it searches for water pollution and transmits information about them to the shore.
Here in Spain, in the port of Gijón, a prototype is being tested, which in the future may become the ancestor of a new unit of the naval police.
“The idea is to monitor pollution in real time. As soon as someone drops the chemicals or there is a leak, we can immediately receive a report and find out what caused the problem to stop it,”explains Luke Speller, Senior Research Scientist, BMT Group Research, a diversified consulting firm.
The company is part of the Shoal consortium, a European Commission-funded science and business group that developed the technology for these underwater operations.
“Currently, water samples are collected in ports about once a month,” continues Dr. Speller. “And if, in between, any ship entering the harbor drops chemicals or a leak occurs, the pollution will spread everywhere, right down to the coastline. The robot fish will be in the port all the time, constantly checking for environmental pollution."
The robot is about 1.5 meters long, it quite accurately simulates the movement of a living fish. The robot was inspired by nature, according to Ian Dukes of the University of Essex, another partner in the consortium. “For millions of years, fish have perfected their hydrodynamic shape, and we have tried to mimic it by developing a robot. They swim like fish, are very agile, and can quickly change direction even in shallow water."
Compared to other autonomous underwater vehicles, robotic fish have other advantages.
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“Traditional robots use propellers and motors,” says Dr. Duke. “We are trying to use the fish fin to navigate the water. The fin is a very effective tool, especially in shallow water and where there is a lot of debris. We can work in difficult conditions, where, as a rule, breakage of the propeller cannot be avoided."
The robot fish uses microelectrode arrays to investigate contamination. In its current state, the robot is able to detect phenols and heavy metals such as copper or lead, as well as determine the oxygen content and salinity of water. However, the team of scientists is trying to achieve broader possibilities.
Dr. Speller explains: "We designed it so that it is possible to replace chemical sensors, set to something else, such as sulfates or phosphates, depending on the water area being monitored."
Having "sniffed" the problem, the robotic fish use artificial intelligence to track down its source. They can work independently or in a team, communicate with each other by acoustic signals and constantly report to the shore.
Trials in Gijón are being conducted to test all of these technologies and generate data to complete the development of robots.
“When we have a prototype in our hands, we know what needs to be done to bring it to the level of a complete commercial system. We hope this can happen in the next few years,”says Dr. Speller. “In the future, I would like to see multi-tasking robots aimed at performing more than just one narrow task. Robots that can search and rescue, monitor divers and track pollution at the same time.
The Department for the Environment Food and Rural Affairs (Defra) estimates that in England and Wales alone, water pollution in rivers, canals, lakes and coastal waters costs £ 1.3 billion a year. …
It will take some time for robots to become permanent inhabitants of water bodies. Each prototype is priced at around £ 20,000 at current prices, although costs are expected to come down when production begins.
An additional difficulty is the insufficient capacity of the storage batteries. So far, robot fish require recharging approximately every 8 hours.
According to Richard Harrington of the Marine Conservation Society, if robotic fish can overcome the above obstacles, they will have a great future. According to him: “Ports, harbors and river estuaries may in the future become places for regular monitoring of pollutants. Remotely controlled devices can be quickly deployed in shallow water bodies, which will allow timely response and take corrective measures."