Science at UM [S04-ep17]: Deciphering dolphin whistles
This week on A l’UM la science, Loïc Lehnohff and Bastien Mérigot, researchers at the Marbec laboratory, Marbeclaboratory, attempt to decipher dolphin communication in order to combat accidental fishing. The report takes us to Celimer to introduce us to biologging. Finally, our last-minute guest, Annaëlle Francia, presents the program for 8 Days of Biodiversity. A program broadcast every Wednesday on Divergence FM 93.9.
The first sailors in the Vendée Globe race, who set sail from Les Sables d'Olonne last November, must have noticed a significant change in the Bay of Biscay when they arrived at the end of January. Not a single trawl net, fishing net, or deep-sea seine net in sight. And for good reason: since January 22, 2025, fishing boats longer than 8 meters have been banned from the cold waters of this area of the Atlantic until February 20.
The goal? To give dolphins, whose populations are increasingly threatened by so-called accidental fishing, a little breathing room. In 2019, the number of dolphins killed unintentionally was estimated at 11,500 (8,900 in 2021), while the International Council for the Exploration of the Sea (ICES) has set the threshold for endangering this population at 4,900.
On October 23, 2023, under pressure from a European directive, the minister responsible for maritime affairs issued a decree banning fishing in the Bay of Biscay for four weeks during the winters of 2024, 2025, and 2026. While the measures taken in the winter of 2024 were, like those against neonicotinoids, largely rendered ineffective by exemptions that were later deemed illegal by the Council of State, the ban in the winter of 2025 is much stricter, much to the chagrin of fishermen.
So is it possible to reconcile industrial fishing with ocean conservation? Scientists are working on developing devices that could limit damage by alerting dolphins and other small cetaceans to the presence of these nets. If forewarned is forearmed, how can we communicate with these animals, whose reputation for intelligence is well established? By using acoustic beacons! Bio-inspired beacons are being developed as part of the DolphinFree project led by Bastien Mérigot, a researcher at the Marbec marine biology laboratory. Together with Loïc Lehnohff, also a researcher at Marbec, they have been working on the sounds emitted by these marine animals in the presence of the beacon or fishing nets, using artificial intelligence. They talk to us about their publication Characterization of whistles using artificial intelligence: responses of short-beaked common dolphins (Delphinus delphis) to a bio-inspired acoustic attenuation device.
In the second part of the program, we head to Sète, where Laurent Dagorn from theMarbeclaboratory takes us to the Center for Coastal and Marine Studies (Celimer) to see the biologging platform, a technique for tagging marine animals with beacons that allow their movements to be tracked.
At the end of the program, Anaëlle Francia, a master's student in environmental and biodiversity management, gives us the program for the 8 days of biodiversity that will take place at several sites in Montpellier from February 12 to 19.
At UM Science, you have the program, so let's get started!
Co-production: Divergence FM / University of Montpellier
Host: Lucie Lecherbonnier
Interview: Lucie Lecherbonnier / Aline Périault
Reporting and editing: Lucie Lecherbonnier
Production: Robin Laillou
Listen to the program “A l’UM la science” on Divergence FM 93.9
