Life on the Edge: Unraveling Arctic Microbial Transformations from Winter to Summer

The enormous diversity of prokaryotes and protists plays crucial roles in marine ecosystems through unique metabolisms. However, how this diversity interacts with and is impacted by global warming in the Arctic Ocean remains largely unknown. This gap is particularly evident in Kongsfjorden, where microbial communities are essential for biogeochemical cycling and ecosystem functioning. As a natural laboratory at the interface between Atlantic and Arctic water masses, Kongsfjorden is key for studying climate change effects. Despite its importance, our understanding of microbial dynamics during winter and spring remains limited due to scarce data. These seasons are critical for microbial activity and community shifts, driven by the transition from polar night to midnight sun and the onset of the spring bloom. As these changes occur, Atlantification, marked by the influx of warmer Atlantic water, may significantly alter microbial communities. However, the specific effects on prokaryotic and protist communities, as well as their interactions, are still largely unknown. To address these gaps, we propose a comprehensive study of microbial communities in Kongsfjorden, focusing on the understudied winter-spring transition. This project will combine field observations with laboratory incubations simulating Atlantification conditions. By manipulating Atlantic water presence, we aim to understand how these factors influence community composition, metabolic activities, and interactions between prokaryotes and protists. Using next-generation sequencing (NGS) techniques, such as metabarcoding and metatranscriptomics, we will characterize community structures and functional responses under varying environmental conditions. This project is essential for predicting the resilience of Arctic marine ecosystems to climate change and for informing conservation strategies to protect these vulnerable environments.