In a context where marine animals are subject to major environmental changes, it is necessary to understand which factors impact on their health and acclimatisation capacity. Among these factors, animal-associated microbiota, which play a major role in host physiology and health, are an essential key to understanding marine ecosystems. In marine bivalve molluscs, the interactions between the environment, diet, digestive microbiota and other associated microbiota (fluids, mucus, shell secretions, etc.) and their impact on host physiology and health are not yet known, nor is it known how these parameters might play a role in their environmental acclimatisation.
The main objective of this study is to characterise the bacterial diversity of digestive microbiota of oysters (Crassostera gigas) and clams (Ruditapes philippinarum) using high-throughput microscopy and metabarcoding techniques. The interest of this study lies in our ability to study in sentinel animals (site BR08), the inter-individual variation and temporal dynamics of their digestive microbiota (distinguishing between autochthonous and allochthonous bacteria), while linking these dynamics to host physiology and environmental variations (biotic and abiotic data), with a particular focus on the duration of exudation and nutritional sources.