The BIOMIN project is an integrated study on the link between biodiversity/fauna activity and mineralization of organic matter based on a diversified ecological situation (quality of OM and micro/macrofauna). Therefore, the main objective is to study the effects of benthic fauna diversity on processes on bioturbation (bio-irrigation, reworking of sediment), mineralization of organic matter and the fluxes of the main biogenic elements at the water-sediment interface. In this context, it will involve: 1) Characterizing the biogeochemical properties of interstitial waters and sediment (diagenetic species, nutrients, organic matter, radio-elements); 2) Defining benthic fluxes at the water-sediment interface; 3) Characterizing the biodiversity of benthic fauna and the intensity of the bioturbation. This falls under the BIOMIN (EC2CO-PNEC & LEFE-CYBER) project.