The project is organised around a consotrium (INRAE, UA, ENSAIA and SOMARA company) to evaluate an agro-energy solution for the treatment of sargasses: methanisation and compost The project will propose the establishment of an integrated chain including collection, storage, anaerobic digestion and finally the return to the soil of digestates free from any source of contamination and pollution. WP1 deals with the large-scale collection of sargasses (taking into account respect for animal biodiversity associated with sargasse rafts). WP 2 carries the physico-chemical analysis and characterisation of Sargasses + comparative study of different treatment scenarios and storage of sargasses. WP3 deals with the methanogenesis properties of sargasses taking into account the impact of inhibition factors on anaerobic digestion in order to obtain an adequate methodology for the fermentation of sargassum. WP4 focuses on the development of “food rations” in anaerobic digestion units with technical-economic-financial assessments. WP5 will explore the feasibility of fertilising soils with “healthy” digestates from LNG. WP6 brings together all WPs to define scenarios for the biotransformation of sargassum coupled with the resources of the territory and agronomic valorisation of digestates.