How noisy is the largest naturel deep lake in France?
Résumé
Anthropogenic (man-made) noise is one of the less visible but widespread symptoms of human activities around the world. Its ecological impact on fresh waters remains under investigated. French peri-alpine lakes are key resources for the territories. With the development of tourism and transport, noise emissions from human activities are at the heart of social, economic and environmental issues. The POLLUSON project aims at quantifying noise pollution and its impacts on wildlife in Lake Bourget, the French largest natural lake. We used scientific diving to set up underwater acoustic recorders at five strategic locations that differ in terms of noise exposure. Diving allowed us deploy the recorders on appropriate substrates, to check their functioning and to collect the data every four months. We assessed the phenology of noise pollution, calculated the increase in sound level and used unsupervised automatic approaches to characterize the diversity of artificial sounds.