ChORhizO

ChORhizO aims to quantify the role of Rhizaria in modern oceans, extending from the surface to the seafloor, over their entire diversity, from living cells to fossils. The ChORhizO project will provide a holistic and cross-disciplinary view, bridging disciplines from oceanography, biogeochemistry, to micropaleontology. Rhizaria stocks, gravitational fluxes, and fossil records will be quantified using a variety of innovative methods, from experimental to in situ approaches. Oceanographic expeditions will be conducted in two contrasted oceanic basins (the Southern Ocean and Mediterranean Sea), where we observe imbalances between Rhizaria biomass and fossil composition. These basins will provide us with an opportunity to consider diverse water column alteration processes that govern fossil record formation. New Vision moorings will be developed to investigate the detailed interplay between stocks and fluxes, ultimately fuelling fossil records. Over a period of two years, they will simultaneously quantify in situ both aspects at unprecedented scales: specimens spanning five orders of magnitude in size will be quantified along the entire water column. A precise understanding of how and which populations are reflected in fossil records will allow us to quantify the magnitude of modern biogeochemical cycles