Plouf 2 – Pollution of high-altitude lakes and observation of recreational uses

The Plouf 2 project will continue the work initiated in 2024 as part of the Plouf project – testing water quality measurement protocols and an exploratory questionnaire survey – with a more ambitious sampling plan in terms of the choice of lakes.

It will seek to better understand the dynamics of recreational use (user profiles, activities practiced, etc.) and will be an opportunity to test new indicators of human pressure on a much-frequented mountain lake, Lac du Lauvitel in the Écrins massif.

On the one hand, the project proposes to carry out a sociological survey in the vicinity of ten lakes located in the Parc national des Écrins and the Réserves naturelles nationales de Haute-Savoie (methodology validated on two lakes in 2024) to document the socio-demographic profile of users, their lake-related practices and their representations of these spaces. The Vanoise and Mercantour National Parks are also involved in the survey, adding 8 lakes to the sample.

On the other hand, exploratory analyses will be carried out to assess the relevance of two potential markers of anthropogenic pressures, by carrying out chemical and microbiological analyses of the water (via the study of human DNA present in the water – proxy for human frequentation) and the search for organic UV filters from sun cream (impact of human frequentation).

This integrated approach to uses and their pressures will enable us to make recommendations to mountain lake managers (protected areas, communes or communities of communes, tourist offices, etc.) and to the various users (mountain socio-professionals, nature sports enthusiasts, etc.), suggesting more effective management tools targeting proven sources of disturbance and the lakes actually affected.

In addition to lakes in the Écrins and Haute-Savoie Nature Reserves, the survey will also be deployed on other lakes in the Vanoise and Mercantour National Parks as part of the new

Researchers associated with the Plouf project :

Carole Birck (Asters-CEN74), Marine Souchier (Carrtel), Jean-Luc Boudenne (LCE, Université Aix-Marseille), Raphaelle Napoléoni (Aster-CEN 74), Clotilde Sagot (PNE).