The Garonne Dordogne watershed is one of the last basins in which all species of highly amphiphrine migratory species are still present.The main objective of the programme is the preservation of migratory species such as aloses, lampreys and eel. Several axes of work are developed in the Garonne Dordogne Leyre basins, the Médocain Lakes and tributaries of the Arcachon basin, including measures to monitor reproduction and general population status. The implementation of concrete actions to restore ecological continuity contributes to the improvement of habitats essential for their growth and development.