Research Assoc. Prof. Dr. Kai Ziervogel 

The world’s oceans absorb about 25% of carbon emissions per year. A significant fraction of this carbon is stored in the deep ocean through gravitational sinking of dead or decaying organic matter. This pathway of carbon storage is called the biological carbon pump (BCP), which is instrumental in regulating atmospheric CO2 levels and thus global climate. Marine microbes play a key role in the BCP through carbon uptake (photosynthesis) and subsequent biomass production in the sunlit surface ocean. Considerable effort therefore has been devoted to measuring rates of microbial carbon uptake and transformation under different environmental conditions. Comparing rate measurements from different areas of the ocean is often difficult due to variations in sampling and analysis procedures among research groups. Coordinating these efforts among experimentalists is important because rate measurements of microbial carbon processing are key input parameters for ecosystem models that predict the ocean’s carbon storage efficiency in a changing climate. This project aims to develop a framework for a more coordinated sampling and sample processing protocol for microbial rate measurements that will help harmonize rate measurements and thus improve the accuracy of ocean models.