The melting of the cryosphere is among the most conspicuous consequences of climate change, and a significant source of freshwater to the Southern Ocean (SO). As a crucial sink for atmospheric carbon dioxide (CO2), anticipated physical changes in the Southern Ocean will bring modifications to its biogeochemical processes and role in the Earth climate. Predicted increases in iron and nutrient influx to the SO surface waters are likely to impact its primary production and contribution to biological carbon export. However, there remains uncertainty about the significance and magnitude of these projections on primary producers, with likely consequences on the rest of the marine ecosystem. CRYOMICS aims to characterise and quantify the fate of cryospheric exported bioavailable nutrients, trace metals and carbon on phytoplankton utilisation pathways with broader implication on the functioning of the biological carbon pump in the KHS. We hypothesise that biogeochemical enrichment from melting ice shelves leads to a direct positive response of the phytoplankton and sea ice algae community, enhancing its productivity and metabolic functions while favouring larger-celled species such as diatoms. Focusing primarily on the understudied Kong Håkon VII Sea (KHS) in the Eastern Weddell Gyre, along a unique cryosphere-ocean continuum, CRYOMICS combines intensive sampling, biogeochemical analyses and metagenomics to systematically understand the structure and function of microbiomes in marine ecosystems associated with the cryosphere and amidst contemporary changes. Through the support of the MSCA, this project will provide a coordinated and comprehensive dataset of this region of the Southern Ocean, shedding light on microbial interactions and their potential vulnerabilities to perturbations, a dimension currently lacking in climate models. This invaluable insight will enhance our understanding of future projections for the Southern Ocean, including its impact on Antarctic Sea ice.