Acoustics on marine mammals

In October 2023, I completed a contract in acoustics as - Passive Acoustics System Operator (PAM) - in the detection and automatic identification of marine mammal vocalizations. We used software parameterized for the frequencies emitted by certain marine animals. during the dredging of the Rivière-du-Loup marina (QC, Canada). We're in the Saguenay-St. Lawrence Marine Park, and the beluga (Delphinapterus leucas), which lives year-round, occasionally frequents the area. So, in the event of intrusion by this protected animal into the dredging or sediment dumping zone a few kilometers from the port, work had to be stopped until the animal had left the area. The sounds were retransmitted on computer screens in a trailer on the marina quay. Sometimes I could hear the animal's sounds. We had three hydrophones around the dock and another at the release. I had to be on the lookout for the vocalizations of a minke whale (Balaenoptera acutorostrata) or a harbour porpoise (Phocoena phocoena). Even if these two species are not endangered and rare in the area, if they were detected on my spectrogram, I had to stop dredging. Several acousticians took it in turns, 24 hours a day, to carry out this mission, as soon as the weather allowed the work to be carried out by the marine firm. An observer (OMM) is out during the day in case a beluga whale enters the 400-meter perimeter, and can also call a halt to the work. This dredging is done every autumn to enable the ferry (with cars) to make the trip from Rivière-du-Loup (QC, Canada) to Saint-Siméon (QC, Canada) on the north shore of the river.