Towards marine microbiome community bioindicators for monitoring Arctic plankton in response to climate change

The Arctic is being heavily impacted by climate change. The air temperature is rising more than 2 times faster than the rest of the globe, sea ice cover is shrinking every year and we are observing increased freshwater inputs from melting coastal glaciers (Ardyna & Arrigo, 2020).

We attempt to quantify the impact of these evolving parameters on the Arctic marine microbiome, which is at the base of the marine food web and ecosystems. In particular, we develop meta-omics-based bioindicators, targeting bacterial plankton, and investigating community growth rates as a key ecological trait to study the global plankton response to environmental changes. This adaptive phenotypic trait, which has been shown to consistently vary with water temperature in non-Arctic bacteria (Abreu et al., 2023), can be estimated for single organisms and can also be averaged to capture the evolution of an entire community.

Here, we compare multiple methods linking omics data to growth rate and explore how the relationship between growth and temperature behaves in Arctic waters. We demonstrate its robustness by quantifying the impact of nutrients on the temperature-growth rate relationship. Finally, we integrate data from ocean and sea ice ecosystems collected during large-scale Arctic campaigns (i.e., TOPC, FRAM, MOSAIC, Refuge-Arctic) in order to decipher the spatiotemporal distribution of this relationship in the Arctic.

Altogether, this work will be instrumental to understand the various local responses of the Arctic microbiome ecosystems to contrasted perturbations.