INBREATH investigated how invertebrate-bacterial associations shape benthic ecology and biogeochemistry, focusing on seagrass ecosystems. These associations influence nitrogen transformation through the combined effects of invertebrate bioturbation, which creates microhabitats for specialized bacterial communities, and the activity of the associated microbiome. The project integrated field surveys and incubation experiments with methods such as biochemical assays, stable isotope probing, and high-throughput sequencing. This approach revealed the taxonomic and functional diversity of the microbiome and quantified the contribution of invertebrate-bacterial interactions to nitrogen fluxes at the ecosystem scale.