On this day of strong mistral, a few gusts of iodine whip faces and a rough sea capsizes the hearts of the best. From every hollow came the screams of the sixty students from the Korsec School and the Versailles College who, on March 31st, left the Old Port on board thehelios.
Make your way to the Frioul archipelago, where the hybrid ship anchors not far from the calmer shores of the island of Pomègues, to take part in a workshop to discover underwater soundscapes, organized under the auspices of the association Opera mundi, the city of Music and the Parc des Calanques.
Symphony of the Living
A few meters deep, bioacoustician Lucia Di Iorio immerses the receiver of her hydrophone, a microphone that picks up underwater sounds. Everyone is silent under the azure sky to listen attentively to the first recording that reveals its characteristic rippling.
« It reminds me of the sound of the waves », a student starts while another points out « a fryer “. Falling stones, the sound of rain, exploding popcorn, even SpongeBob: the more or less whimsical interpretations of this acoustic symphony capture the imagination before the marine biologist betrays its author. This regular crackling is that of the “pistol shrimp” or “clap shrimp”, Crustaceans that curl up under the rocks and, as their last name suggests, break their large claws by creating a nearly 220 decibel detonation. which creates such a shockwave that it stuns its prey », emphasizes Lucia Di Iorio. And to discover that sea urchins can also mingle in this cacophony of life. by the cracking of its skeleton and the friction of its spikes as it moves “. If he knew the song of dolphins or whales, Farès, a student of 3e at Versailles College, was far from ” that there are so many animals in the sea that make different noises to communicate ».
Speed and functions of sounds, the concept of frequency… the questions will be refined over the course of the workshop. A curiosity to which the biologist responds. ” These sounds give us another access to information about the diversity of organisms or their behavior. This makes it possible to identify the function of a habitat, for example in relation to reproduction. It also allows to understand the human pressures that can influence the behavior of animals. explains Lucia Di Iorio, who is working on the construction of a Global Sound Platform that collects all ocean sounds to identify biodiversity hotspots, monitor their evolution and even enable shazaming [identifier par reconnaissance sonore, Ndlr] a recorded sound ».
« This research paper is a fabulous teaching tool for us. ” emphasizes Francis Talin, Education Manager of the Calanques National Park. ” Hearing the fish sing is a unique discovery that allows aconnection with nature. »
“These sounds give us another access to the diversity of organisms”