Biogeochemistry of dispersed permafrost ice as a source of carbon, nutrients and microorganisms for Arctic surface waters.

AXIS 2: Coupling of biogeochemical cycles in a context of global change

Bio-Permaf-Ice 2025: Biogeochemistry of dispersed permafrost ice as a source of carbon, nutrients and micro-organisms for Arctic surface waters

Peat-rich permafrost zones, which store a third of the world's soil organic carbon, are threatened by global warming. This destabilisation could intensify the export of organic carbon to rivers and the ocean, while increasing greenhouse gas emissions. In this context, the Bio-Permaf-Ice project aims to better understand the vulnerability of permafrost and surface water to climate change.

Building on the continuity of the research initiated in 2024 in Churchill, the mobility project planned again on site in August-September 2025 aims to deepen the initial results concerning the degradation of organic matter in surface water through new in situ biophoto-degradation experiments.

This mobility project will make it possible to draw on the technical environment of the Churchill Northern Studies Centre (CNSC), but also to take advantage of the new resources that will be made available by the Churchill Marine Observatory (CMO). The analyses in Toulouse will include the quantification of dissolved organic carbon (DOC), organic carboxylic acids, major and trace elements, the speciation of nitrogen (N) and phosphorus (P), as well as the quantification of microbial content (flow cytometry) and the metabolic diversity of communities (heterotrophic aerobic activity using Ecoplates Biolog).