Shifts in sediment bacterial communities reflect changes in depositional environments in a fluviatile context.

Sediments are complex heterogeneous matrices allowing to some extent the recording of past environmental conditions by integrating sediment characteristics, contamination and the microbial community assembly. In aquatic environments, abiotic environmental filtering is considered the primary deterministic mechanism shaping microbial communities in sediments. However, the number and relative contributions of geochemical and physical factors associated with biotic parameters (reservoir of microorganisms) complicate our understanding of community assembly dynamics.

Decoupled responses of the copepod Eurytemora affinis transcriptome and its microbiota to dissolved copper exposure.

Chemical contamination is a common threat to biota thriving in estuarine and coastal ecosystems. Of particular importance is that trace metals tend to accumulate and exert deleterious effects on small invertebrates such as zooplankton, which are essential trophic links between phytoplankton and higher-level consumers in aquatic food webs. Beyond the direct effects of the contamination, we hypothesized that metal exposure could also affect the zooplankton microbiota, which in turn might further impair host fitness.