By Sofia Paraskevopoulou
In July 2025, I embarked on an expedition aboard SVEA, the SLU research vessel, to explore the microbial life of the Swedish fjords. Our mission: to investigate how eukaryotic communities shift across oxic, hypoxic, and anoxic zones. This provides natural gradients that offer a natural laboratory of how life copes with low-oxygen conditions.
Over the course of the expedition, we collected a variety of samples using gravity cores, GMAX cores, and CTD water profiling systems, targeting both the water column and sediments across oxygen transitions. These samples will allow us to track changes in microbial eukaryote diversity and function along the redox gradient.
We will apply amplicon sequencing to identify community composition, and use metatranscriptomics to determine which genes are actively expressed under varying oxygen gradients. This will help us uncover how protists and other microbial eukaryotes adapt their metabolism and interactions in response to oxygen loss, critical knowledge in a warming world where hypoxia and anoxia are on the rise.
We are excited to dive into the data and share what we discover.
