Unlocking the Potential of Distributed Acoustic Sensing for Ocean Monitoring and Management

Distributed Acoustic Sensing (DAS) is an innovative technology that transforms optical fibers into dense sensor networks capable of detecting and locating acoustic disturbances over long distances, with an accuracy of one meter and potentially over several tens of kilometers. By sending LASER pulses into the fiber and analyzing the phase difference of the signal reflected along an optical fiber, DAS enables to obtain a continuous and extensive amount of information, exploiting the submarine telecommunications cables already deployed. With around 1.2 million kilometers of undersea cable carrying 98% of the world's digital communications, this passive infrastructure represents a unique potential for ocean knowledge and management, combining logistical and economic efficiency. Initially adopted for marine and terrestrial geophysics, then extended to fields such as cetacean tracking and oceanography, we have conducted several experiments demonstrating its effectiveness in new applications, such as monitoring communications between underwater drones and detecting sounds emitted by fish of major interest (threatened, regulated, with heritage or socio-economic value, etc.) like grouper species (e.g., Epinephelus marginatus).

These advances open up new prospects. Acoustic monitoring of fish species of major interest become a valuable tool for identifying and conserving marine biodiversity. In addition, detecting underwater drones in the proximity of cables represents a challenge for the safety of sensitive infrastructures and also offers an opportunity to improve the positioning of autonomous underwater drones (UAVs) used to map and monitor the seabed.