MARUM Research Academy

Polar Microbiomes: Composition, Function and Connectivity Over Space and Time

The polar oceans are changing, with impacts on the entire ecosystem − from sea-ice and seawater to the deep sea. Microbial communities play a vital role in ecosystem functioning by driving biogeochemical processes and biological interactions − yet little is known about their structure and function in polar oceans, and how their dynamics scale across environmental and spatiotemporal gradients.

My doctoral research project will focus on the composition, function and connectivity of microbial communities in the Arctic and Antarctic Oceans across seasonal and environmental gradients. Using ribosomal metabarcoding, I will assess the dynamics and stability of Arctic microbiomes in seawater and sea ice in the central Arctic Ocean across years. Integrating barcoding and metatranscriptomics will reveal depth and geographic signatures in taxonomic as well as metabolic structure, illuminate community-wide gene expression, and resolve patterns of microbial interaction and interdependence that shape biogeochemical cycles.

Finally, I will address the question of whether microbial communities in the Arctic Ocean exhibit common or unique trends in gene content and community composition compared to those found in the Antarctic Ocean. This bases on long-read metagenomes from year-round autonomous samplers in the Fram Strait and Weddell Sea.

In conclusion my doctoral project will identify key microbial populations and functions in polar oceans. Filling this knowledge gap is crucial to gain a holistic picture of Arctic and Antarctic microbial communities, cryobenthopelagic coupling and its spatio-temporal dimensions. These findings facilitate predictions about microbial responses to climate change, and how this will impact polar ecosystem functionality as well as biogeochemical cycling.