The Southern Ocean is responsible for 40% of the oceanic uptake and storage of anthropogenic CO2 and the drawdown of CO2 via photosynthesis by Southern Ocean phytoplankton accounts for 10% of this uptake. Phytoplankton forms the basis of the Southern Ocean food web supporting large animal populations from krill to whales. Currently, the Southern Ocean is facing dramatic climatic changes (ocean acidification, altered trace metal availability, increased vertical mixing, warming) and the impacts on phytoplankton species composition and productivity and their consequences on the biological carbon pump remain a major field of research. Hence, to assess how global change will affect phytoplankton biodiversity, ecology and biogeochemistry the combination of field and laboratory experiments and their integration into models is required to generate a mechanistic understanding of responses from the species up to the ecosystem level. During the last years, my research has substantially contributed to a process-based understanding on how trace metal availability under future global change scenarios (especially ocean acidification) will affect Southern Ocean phytoplankton ecology and biogeochemistry. Based on the results obtained on the basis of the Helmholtz Young Investigators grant new future research directions have been developed, highlighting the need to assess, beyond iron, the influence of other trace metals such as manganese, cobalt and zinc as they were identified to act as limiting or co-limiting nutrient and to influence Southern Ocean phytoplankton composition and productivity. In this respect, a strong focus in my future research will be to better constrain how natural trace metal sources such as dust, ice melt, sediments, upwelling and grazers affect Southern Ocean biogeochemistry in the context of climate change. A better link in future research spanning from bacteria, phytoplankton and zooplankton interactions up to higher trophic levels will be crucial for accurately predicting the consequences of ongoing anthropogenic perturbations to Southern Ocean biogeochemistry. In this presentation, I will present on-going research projects and future research directions and point out potential for interdisciplinary collaboration.