These sampling efforts are designed to provide high-quality, representative material for studying benthic methane dynamics and to support cross-system comparisons relevant to understanding methane cycling in sensitive marine environments.The MOXy-Filter project will generate new insights into methane (CH₄) cycling in pelagic and benthic marine environments by linking geochemical measurements with microbial community composition and function. The collected samples will enable identification of key CH₄ oxidation pathways and associated microbial taxa across diverse ocean settings. Comparative analyses will clarify whether similar processes occur between marine sediments and other CH₄-rich systems, such as lakes. The results will improve understanding of the role of benthic microbes as a biological filter for CH₄ emissions and their potential response to environmental change. Outcomes will include high-resolution datasets, metagenomic resources, and peer-reviewed scientific publications.

Project activities aboard the vessel will focus on the targeted collection of bottom water and, where feasible, surface sediments. Sampling will be conducted at selected stations, in close coordination with the crew and possibilities available, which can either be three stations in the same proximity (creating triplicates) from one region or a transect across a region. Overall, we would like to collect water from as diverse sites as possible.

At each station, 10 L of bottom water will be collected close to the seafloor using our hand-held niskin bottle or a CTD (if available) to capture the pelagic community, while sediment could be collected using a van-veen grab (Stockholm University owned) to obtain the uppermost, microbially active sediment layers. Samples will be processed immediately after recovery through subsampling and appropriate storage to preserve in situ characteristics.