(Lorient) To reduce the catch of species not targeted by fishing, a team from a French research institute, Ifremer, is testing smart trawls in Lorient allowing fish to be sorted before they are even brought back on board boats. and limit the impact on the marine ecosystem.
“A trawl is like a large dip net, it is towed behind the vessel for several hours without knowing what is going into it in real time, namely are these species that are targeted by the fisherman or not. », Illustrates to AFP Julien Simon, of the Laboratory of technology and halieutic biology of Ifremer.
With other partners, including the University of South Brittany (UBS), the company Marport, specializing in high-tech sensors, and the fisheries committee of the Morbihan department, the public institute is piloting this intelligent trawl project called Game of Trawls, play on words with the hit series Game Of Thrones and acronym of Giving Artificial, Monitoring intElligence tO Fishing Trawls.
Each year, 20 million tonnes of fish, or about a quarter of total marine catches, are discarded at sea or brought back to quay although not exploited, according to the Food and Agriculture Organization of the United Nations (FAO). .
Variable depending on the target species, the rejection rate in the case of sardine fishing is 22%, when it reaches 41% for langoustine fishing, according to data from the French Research Institute for exploitation of the sea (Ifremer).
Despite increasingly selective fishing gear, thanks to adapted sizes and shapes of mesh, their effectiveness still depends on the willingness or not of the fish to extract themselves from it and not on a decision by the fishermen.
“The fish often adopt an avoidance behavior when faced with the mesh of the nets which ultimately means that they stay inside”, explains Julien Simon, also emphasizing the “shoal effect”.
The smart trawl constitutes “a decision-making tool for fishermen”, assures the engineer, whose project is based on recent technological advances in the fields of artificial intelligence and sensor networks.
“Tech-packed”
Equipped with cameras, sensors and powerful analysis software, the device thus makes it possible to inform the fisherman in real time of the species caught, their size and their abundance.
“I am not interested in having the fish on the deck and sorting it once it is dead, I prefer to sort it on the bottom”, notes Éric Guygniec, head of the Breton armament company Apak and project partner. With such a device “we know at all times what goes into the net, the size of the fish and the species, and if the species is not of interest to us we can open a trap,” he explains.
In addition to this innovative pelagic net device, that is to say moving between the surface and the bottom without coming into contact with it, a bottom trawl, also equipped with cameras and sensors, is being tested in Lorient. But this time the device aims to preserve the marine ecosystem as well as possible.
“Depending on the presence of targeted or non-targeted species, the trawl will switch to fishing or flight mode in order to avoid having an impact on the seabed,” explains Julien Simon, in front of a prototype submerged in this basin where a current is generated in order to simulate the advance of a boat.
However, on the docks, some sailors are worried about the cost of such a device. Even if, like any virtuous innovation, it could give rise to the right to aid when it is put on the market by 2025.
“Can we buy a trawl like this stuffed with technology?” », Wonders a fisherman from Lorient who did not wish to give his name. He says he recently put his boat up for sale due to “too heavy” constraints weighing on the profession.
“It will certainly have a cost”, also warns Soazig Palmer-Le Gall, who is notably president of the producer organization (OP) Pêcheurs de Bretagne.