The aim of this project is to understand the exchanges between the groundwater and the water in the Sélune river. This knowledge will help prevent the physical, chemical, and biological changes that restoring continuity will cause to the water quality of the Sélune. Data: - water level records - temperature measurement records at various locations in the river sediments and in the piezometers - data from differential pressure sensors at certain points along the river, - data on the concentration of chemical elements (N, P, dissolved gases, etc.) in the sediments - fiber-optic data - Lidar campaign data Sites: At the start of the project, there are two main sites, each covering a few hundred meters, located nearby: - the Signy Bridge - the Biards Bridge Additional sites may be added later, if logistical constraints (such as the portability of certain measurement protocols) permit.

This project assesses the impact of restoring connectivity between fish populations following the removal of dams on the Sélune River. It is based on the calculation of a genetic fragmentation index for five fish species. Data: - Genetic analysis and F-index