A whale stranded in 2021 probably the victim of military sonar

Industrial tests of military sonar in a protected marine area “probably” caused the death of a whale found three years ago on the French coast of the Île de Ré, according to scientists who are calling for more regulation to protect the mammals.

On February 2, 2021, a Cuvier’s beaked whale washed up on a beach in Ars-en-Ré.

The necropsy of this female revealed internal hemorrhages in the lungs, spleen and liver “compatible with traumatic death linked to impulse shock”, relates Jérôme Spitz, co-director of the Pelagis observatory in La Rochelle. From the outset, the sonar track is the subject of “strong suspicion”.

An investigation since carried out by a scientific committee gathered around the Esprit de Velox association, which carries out a research and innovation program on the ocean, has corroborated the hypothesis.

According to the conclusions revealed by the newspaper Sud Ouest and published in October in the journal “Nature Sciences Sociétés”, the animal had died approximately a month before its stranding.

By studying the currents, the researchers reconstructed its drift and located the area of ​​the death off the island of Noirmoutier, in an area classified as Natura 2000.

A military frigate was then operating in this area under the supervision of the industrial company Naval Group, which was carrying out “qualification tests before delivery (…) for a foreign client”, in particular “sonar tests”, confirms Gaëlle Rousseau, responsible for the group’s eco-design.

The manufacturer had asked the Atlantic Maritime Prefecture where to carry out these tests “at maximum power, in classic operational frequencies for submarine hunting”, she adds.

The authorities explain that they indicated the area concerned thinking that Naval Group “would apply the same precautions as the Navy”. “It was the first frigate intended for export to carry out tests. From now on, we will check further,” underlines the Maritime Prefecture, referring to “a fairly unique case”.

Naval Group has since reviewed its procedures. From now on, he gradually increases the power of the sonars “so that the sound scares away disturbed animals before injuring them” and makes sure not to carry out the tests in a protected area.

However, the regulations in force in protected areas remain very fragmented. It does not take into account the “impulse” noise, characteristic of sonar, but only that linked to propulsion, and only for civilian ships.

However, “we cannot ask others to be very careful 365 days a year, so that the 366th, a warship comes to kill whales”, remarks François Frey, founder of Esprit de Velox which advocates a real “take into account” of marine protected areas.