Over the past two months, nearly 400 dolphins have been found stranded on Atlantic beaches, mainly in Vendée and Charente-Maritime. According to the Pelagis observatory (La Rochelle University-CNRS), these strandings represent only a small part of the mortality of common dolphins, estimated at between 5,000 and 10,000 individuals each winter. Main cause of this “hecatomb”, denounced by environmental associations: accidental captures by fishing boats, particularly numerous in winter. They would currently be 1,500 in the Bay of Biscay.
Closer and closer to shore
“This process began in the late 1990srecalls Hélène Peltier, research engineer at the Pelagis observatory. But he had settled down before coming back in force after 2016. The dolphins would move closer and closer to the coasts to find their food, entering into direct competition with the fishermen.
“Before, they were off and we didn’t see themconfirms Adrien Delavaud, commander of a gillnetter on the island of Yeu and vice-president of the Regional Fisheries Committee. No one likes to capture them, especially since it breaks our nets. I prefer to take pictures of them when they are swimming to show them to my daughter…”
Sound repellents
His new fishing boat, christened Camelysis equipped with sound repellents called pingers, placed directly under the hull. “I activate them when I go down and when I go up the netshe says. And only every other day to test their effectiveness. »
Since the launch of his boat last November, he has not caught any dolphins and can hardly assess their effectiveness. For several years, many research programs have been underway, with the profession, to collect data on animal behavior and test technical solutions.
Several scientific publications have already pointed out the limits of pingers. Badly positioned, they can increase the number of captures. Dolphins accustomed to these sounds might even see it as an encouragement to search for food.
reflective nets
Hence the use of other tools such as reflective nets, which are more perceptible by the sonar of dolphins (natural ability to locate themselves thanks to echoes, like bats). It is not a question of frightening them but of helping them to circumvent the nets. Tested on a small number of ships, they have yet to be deployed on a larger scale.
Martin Böye, scientific director of the Planète Sauvage animal park near Nantes, which is home to around ten dolphins, is working with several partners on easy-to-use reflectors that can be clipped onto any fishing net, as fishermen already do. America with soda bottles.
The scientist hopes to test them soon in the basin and then at sea next winter. ‘Worry is research taking time as dolphin stranding continueshe acknowledges. To relieve the pressure, the ideal would be to combine pingers and reflectors with temporary fishing stops. »
“Concerted” solutions?
This is precisely what Sea Shepherd, the League for the Protection of Birds or France Nature Environnement (FNE) are asking for. “We see no other solution than the closure of the most problematic fisheries”, summarizes Benjamin Hogommat, lawyer for FNE in the Pays de la Loire, regretting that the State does not immediately engage this track. The state action plan specifies “that in the absence of satisfactory results on the reduction of accidental catches, spatio-temporal closures will be implemented in the winter of 2024-2025 in the Bay of Biscay. »
A closure of certain fishing areas from January to March, then for a month in the summer “would curb dolphin mortality and rebuild fish stockscontinues the lawyer of the FNE. In the long term, the fishermen will be winners, but it is of course necessary to provide aid to compensate for this cessation of activity. » Adrien Delavaud does not want to hear about it: “Can you imagine the economic and human impact? A job at sea is five ashore. »
But Hélène Peltier sees no other way out either: “Common dolphins reproduce slowly. We cannot wait for their decline to act. Overfishing has already caused the extinction of several species of dolphins such as the badge in China, the little cow in Mexico or maui in New Zealand ».
The “Delmoges” program, conducted between the State, scientists and the profession since March 2022, works in particular on the acceptability of closures by fishing professionals. For the researcher, “the idea is to achieve concerted measures that are not imposed by scientists”.
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Fifteen deputies appeal to the government
In The Sunday newspaperfifteen deputies ask the government “a suspension (for one month) of non-selective fishing techniques in the most sensitive areas”, and propose to compensate penalized fishermen. The appeal was signed by deputies from Europe Écologie-Les Verts, La France insoumise, Renaissance, Horizons et Libertés, Independents, Overseas and Territories (Liot), MoDem and the Socialist Party.