Dr. Irina Köster 

Organic molecules in the ocean perform a wide range of functions: some serve as energy sources for microbes, others act as vitamins, hormones, toxins, or antibiotics. They form a complex mixture that fuels life, mediates interactions, and drives the cycling of carbon and nutrients. Despite their importance, most of these compounds remain chemically uncharacterized, and we still know little about how they are produced or broken down—especially as ocean conditions shift due to climate change. To understand their ecological roles, we first need to resolve their molecular structures, which often determine how they function, how long they persist, and how they influence marine ecosystems. The Bremen–Oldenburg area, with its strong network of marine research institutions, offers an ideal environment for my interdisciplinary research goals. During my HWK fellowship, I will develop a proposal for a Junior Research Group hosted in this region to investigate how environmental factors like oxygen levels, temperature, and nutrient availability affect the production and transformation of these molecules. I will work with local partners to analyze existing datasets and generate preliminary data to support a competitive proposal. My vision is to link molecular-level data, computational tools, and microbial ecology to understand how climate change may reshape the ocean’s invisible chemical networks and the life they sustain.