Exploration and investigation efforts of the past decade have significantly improved our understanding of the biodiversity and distribution of deep-sea chemosynthetic ecosystems. These ecosystems are now known from a variety of environments on the seafloor (e.g.:
hydrothermal vents, cold seeps, deep anoxic hypersaline basins, massive organic falls like whales skeletons, sunken woods,.etc). Also the knowledge of biogeochemical processes and biological interaction sustaining chemosynthetic ecosystems, and their role in the evolution of marine biodiversity is increasing. However, challenging issues remain the discovery of chemosynthetic ecosystems in remote ocean systems, the temporal dynamics of these ecosystems, their influence on ocean biogeochemical cycles, and their sensitivity to anthropogenic impact. In particular, the mechanisms governing the interactions between chemosynthetic communities and the abiotic environment, and the multitude of microbial metabolisms in sustaining these ecosystems need further investigation, especially with regard to quantification. This session will welcome advanced multidisciplinary studies on these unique ecological and biogeochemical ecosystems, as well as technological developments for the exploration, observation, experimentation, and monitoring at various scales on the seafloor.