Marine mammals are emblematic species in the eyes ofthe general public, and they can be seen as underwater witnesses of the rich biodiversity of our seas and oceans. But what does the term marine mammals really mean? It refers to three taxonomic groups: sirenians, which are close relatives of elephants; pinnipeds, carnivorous cousins of our domestic dogs; and cetaceans, with both baleen (whales) and toothed species (dolphins and their cousins). These marine mammal species are often at the top of the food web and stand watch over the quality of the marine environment.
BESET BY THREATS AND IGNORANCE
Many factors threaten marine mammals and at the top of the list is human activity, which is encroaching more and more on the oceans. Although international agreements have been reached on managing the conservation of marine mammals, they are hampered by a lack of knowledge about these large creatures. Indeed, new species of cetaceans are regularly discovered while others are at risk of disappearing before our very eyes. Additionally, it is difficult to accurately identify where they are located and their migration routes.
eDNA AS THE SOLUTION FOR THE FUTURE
For three years now, the UBO (Université de Bretagne Occidentale), the MNHN (Muséum National d’Histoire Naturelle), SPYGEN and the WWF, along with their partners, have been studying marine mammals in the French Antilles and the Iroise Sea with the help of DNA found in seawater samples. All species observed during the field campaign were also detected with eDNA. For example, sightings of false killer whales and tropical pilot whales in the AGOA Sanctuary in Guadeloupe were confirmed by the presence of eDNA.
All species observed during the field campaign were also detected with eDNA.
Within the perimeter of the Iroise Marine Nature Park, it was the very shy common porpoise that was detected. Given these promising results, eDNA will undoubtedly establish itself in the short term as one of the most comprehensive methods to observe and study marine mammals. And, therefore, to better protect them!
