2024/01/24 by Jessica Venetz, Olga M. Żygadłowska, Nicky Dotsios +7 · 1 voice · 2 citations
Earth and Planetary Sciences · Environmental Science · #Marine and coastal ecosystems #Methane Hydrates and Related Phenomena #Microbial Community Ecology and Physiology
paper · pdf · doi:10.1093/femsec/fiae007
openalex publication_date 2024/01/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
In coastal waters, methane-oxidizing bacteria (MOB) can form a methane biofilter and mitigate methane emissions. The metabolism of these MOBs is versatile, and the resilience to changing oxygen concentrations is potentially high. It is still unclear how seasonal changes in oxygen availability and water column chemistry affect the functioning of the methane biofilter and MOB community composition. Here, we determined water column methane and oxygen depth profiles, the methanotrophic community structure, methane oxidation potential, and water-air methane fluxes of a eutrophic marine basin during summer stratification and in the mixed water in spring and autumn. In spring, the MOB diversity and relative abundance were low. Yet, MOB formed a methane biofilter with up to 9% relative abundance and vertical niche partitioning during summer stratification. The vertical distribution and potential methane oxidation of MOB did not follow the upward shift of the oxycline during summer, and water-air fluxes remained below 0.6 mmol m-2 d-1. Together, this suggests active methane removal by MOB in the anoxic water. Surprisingly, with a weaker stratification, and therefore potentially increased oxygen supply, methane oxidation rates decreased, and water-air methane fluxes increased. Thus, despite the potential resilience of the MOB community, seasonal water column dynamics significantly influence methane removal.