Methane production in coastal permeable sediments

This PhD thesis explores a newly recognized source of methane, a powerful greenhouse gas, from sandy coastal sediments. Traditionally thought to be inactive due to oxygen exposure, these sediments are now shown to host methanogenic archaea that produce methane using compounds from seaweed and seagrasses. The research combines fieldwork, lab experiments, and genetic analysis to reveal that these microbes are not only active in oxygen-rich environments but are also widespread. The findings have important implications for climate models and carbon accounting, especially in coastal restoration and “blue carbon” projects aimed at mitigating climate change.