In response to climate change, Natura 2000 sites FR5212008 – Grande Brière, marshes of Donges and Brivet and FR5200623 – Grande Brière and marshes of Donges, are exposed to multiple risks: sea level rise, marine submersion, changes in precipitation patterns, winter flooding, summer dryness, increased intensity and duration of soil droughts. These events can have several impacts on species, natural environments, ecosystem services and human activities, such as: the loss of attractiveness to species of community interest, the disappearance of populations, the modification of natural habitats, the arrival of new alien species, the loss of the carbon storage service, the modification of agricultural practices (abandonment of livestock farming), the intensification of cultivation practices. The Regional Natural Park of Brière, managers of these Natura 2000 sites, has decided to build an applied scientific research system in partnership with the University of Nantes to anticipate the impacts of climate change on these sites and strengthen their functionalities through appropriate management. The project must ultimately make it possible to build, on the basis of robust scientific modelling, informed public policies in terms of adaptation of natural environments to climate change in order to strengthen the resilience of the territories and propose appropriate management.