La Réserve naturelle de Saint-Martin est une aire marine protégée de 30km2 située au nord-est de l’île de Saint-Martin. Créé en 1998, cet espace préserve les cinq principaux écosystèmes de l’île : récifs coralliens, mangroves, herbiers de phanérogames, étangs et forêt sèche littorale. La Réserve gère également les 14 étangs du Conservatoire du littoral et ses 11 km de rivages terrestres naturels.

A Lot Of Noise In A World Of Silence

The sound-recording device from the NOAA © Julien Chalifour

Deep in the seas of the Réserve Naturelle, 15 meters below the surface, a microphone records all of the sounds heard underwater.

And there are lots of them. Natural sounds coming from shrimp, fish, or marine mammals — the primary species concerned by this experience — but also any sound pollution created by humans, such as the noise of motors or that of seismic prospecting. The sound-recording device is programmed to start every four hours, and capture all the decibels it hears over the next hour. Three American researchers from the National Oceanic and Atmospheric Administration (NOAA) and a researcher from the University of Florida , who has set up similar projects on the other French Caribbean islands, installed the microphone in December 2016. These four scientists are working on CHAMP — Caribbean Humpback Acoustic Monitoring Program — a study of humpback whales and other marine mammals. Once the recording devices are collected, an analysis of their data provides information about the species of marine mammals that are heard in relation to the frequency and signature of the sounds. As for the humpback whales, it will eventually be possible to distinguish the number of individual “singers”, as each one has a personal voice in the midst of a common refrain, which itself changes every year.

The Agoa sanctuary for the protection of marine mammals in the French Caribbean has given the Réserve Naturelle another autonomous recording device for a very specific purpose, as it turns on only when it perceives one of the many sounds made by dolphins. This was submerged at a depth of 10 meters, on a mooring line, as dolphins often swim very close to the surface of the sea. This experiment will allow us to know a little more about one of the rare populations of marine mammals that remain in the waters of the Réserve Naturelle throughout the entire year. It is important to note that these two studies are taking place without disturbing the mammals in any way.

All articles from: Newsletter-28

Better Knowledge About Protected Areas And Protected Species

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