Isotopic approaches to unravelling export and recycling processes in the Southern Ocean

Global warming is leading to considerable ice retreat in Antarctica resulting in enhanced iron input into coastal areas, potentially feeding ocean regions where phytoplankton growth is otherwise Fe-limited. West Antarctic Peninsula (WAP) shelf is one of the fastest warming regions at most risk from ice decline. Therefore, it is crucial to understand the main processes promoting CO2 uptake to forecast the potential impact of increased Fe input on biogeochemical cycling. Marguerite Bay, located on the WAP, is considered a 'high recycling, low export' region with blooms dominated by large diatoms, low transfer efficiencies to deep water, and intensive remineralisation and grazing in the upper water-column. This project aims to use Fe and Si isotope geochemistry to investigate the main drivers that regulate export and recycling in Marguerite Bay.