Betrayed by their DNA ?

Collecting and decoding DNA in an ecosystem, or environmental DNA (eDNA), helps detect the presence of species living there. By simply collecting water samples, this tool is used to monitor the progress of amphihaline migratory fish and invasive species on the Sélune river and its main tributaries in the years following the removal of dams.

The genetic marker used (12S mitochondrial DNA) detects the presence of the target species in the water sample after PCR analysis. Monitoring on the Sélune focuses on migratory and invasive species, while analysing the evolution of fish communities as a whole during the restoration process.

Water samples are taken at 33 stations located on the main course and tributaries. This provides sufficient coverage to monitor the species. Monitoring is carried out twice a year: in spring and autumn