No corner of the ocean is spared from noise pollution which disrupts and even kills marine organisms
This pioneer of bioacoustics was awarded the Rolex Prize in 2002 for having designed a system capable of alerting ships so that they avoid collisions with whales. Since then, the watch company has continued to support Michel André. “For twenty years, we believed that large cetaceans were the main animals to suffer from noise pollution. But thousands of species of marine invertebrates, which do not have ears, are sensitive to the vibration of sound to manage their movements. “These species have organs responsible for perceiving the vibration of sounds whose structure is very similar to our inner ear. When marine invertebrates are subjected to an artificial source of noise, they stop feeding and reproducing and die within a few days. After this discovery, Michel André and his team made another, just as major: Posidonia, an aquatic plant present in the Mediterranean which has sensory organs, also dies from exposure to these sound sources. “There is the entire food chain, from plants to whales, including fish, invertebrates and plankton, which is affected by noise pollution.”
An exponential amount of noise
These discoveries come at a time when the amount of noise linked to human activities is exponential at sea: wind farms, oil prospecting, maritime transport, etc. “If corrective measures are not quickly implemented, it is very likely that the ocean will die from noise”. This pollution is not irremediable and unlike other pollution, when the source stops, the effect disappears immediately. And “there are solutions for isolating a ship’s engine room or a wind turbine pylon,” notes the scientist.
To capture these frequencies that are inaudible to the human ear, Michel André and his team use hydrophones, which are microphones adapted for underwater use sensitive to all the frequencies that nature produces. Since sounds travel five times faster in water than in air, and at much greater distances, it is possible to capture sounds from hundreds of kilometers away. “Then, thanks to artificial intelligence, we discern the components of this sound and recompose the soundscape and understand the interactions between the different sources,” he explains. He distinguishes three origins of sound sources: natural – produced by waves, wind, rain, earthquakes –, biological – produced by living organisms –, artificial – produced by humans.
Sensors in the Amazon
André Michel also uses this technology outside of the water. It allows us to understand the recomposition of the Amazon forest following deforestation. “We can finally know if certain species compete with native animals and plants after fleeing,” reports Michel André. But also to witness the regeneration of certain parts of the forest. The bioacoustician thus covered the Mamirauá reserve with sensors; the latter were created almost thirty years ago by another winner of the Rolex Awards, José Márcio Ayres, also awarded in 2002 for his work. This technique was then particularly remarkable and unprecedented in terms of conservation. The support of Rolex was decisive for José Márcio Ayres, who was thus able to expand his research into the neighboring Amanã reserve. Michel André follows in the footsteps of his colleague and now has the objective of covering the entire Amazon forest, present in nine states, in order to take the pulse of the Amazon and really understand why this region, which was the one of the largest producers of oxygen on earth has now become a CO2 emitter. “We must at all costs understand this phenomenon in order to reverse it,” he warns.
In Africa, the bioacoustician and his team set up a listening project to be able to alert rangers in the event of danger to the environment. In India, they developed a mechanism to alert trains to the presence of elephants near the tracks to avoid collisions. “All of this is part of the same approach to applied solutions. But personally, what has fascinated me since I was very little and which made me want to study sounds is animal communication, testifies Michel André. For him, “understanding the communication mechanism of species that are not human and why not, entering into communication with them, is essential to regain balance on this planet.” It’s not science fiction. “We are not far from it,” he assures us. Because for the bioacoustician, there is a universal communication mechanism, shared by all wild species, whether terrestrial or aquatic, which inhabit the earth. “We are the only species on earth that doesn’t understand it. We probably understood it before we began to articulate our language, 150,000 years ago. But since “we have put words to our thoughts, we have become disconnected from its nature. And for the director of the Bioacoustic Applications Laboratory at the Polytechnic University of Barcelona, understanding this universal language is the key to our survival on earth.
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