Methane oxidation in oxygen-depleted waters: rates, kinetics, and responses to environmental change

Aquatic ecosystems are a major source of the potent greenhouse gas methane (CH4) and oxygen (O2)-depleted waters are hotspots for CH4 accumulation and emissions.

Microbial methane oxidation is a key process in mitigating CH4 emissions; however, we lack a comprehensive understanding of the prevalence and magnitude of this process in O2-depleted waters.

Given the expansion of water column deoxygenation worldwide, this is a fundamental knowledge gap limiting our ability to predict and manage CH4 emissions from marine and freshwater environments.In this project, I will quantify the rates, kinetics and environmental controls of methane oxidation in O2-depleted waters in the coastal Baltic Sea and other globally representative O2-depleted marine and freshwater systems.

This project will employ novel approaches to quantify microbial process rates in situ, which will be complemented by laboratory incubation experiments and the quantification of single-cell activities using imaging mass spectrometry and microfluidics.

The aim is to obtain a comprehensive understanding of methane oxidation in response to water column O2 decline from single-cell to ecosystem scales.

Furthermore, the results will provide a holistic regional and global assessment of methane oxidation rates, kinetics, and environmental controls that will feed existing climate models and enhance predictions of aquatic CH4 emissions under projected climate change scenarios.