Background: Increased nutrient input into water bodies and thus increased primary production in the last century lead to an enhanced carbon input into aquatic systems. This increase in organic matter content in turn leads to strong oxygen depletion in the water bodies and therefore also to enhanced methane production. Despite intense restoration measures during the past few decades, nutrient levels in water bodies remain elevated and a good explanation for that is missing. We hypothesize that there exists a previously overlooked sediment transport mechanism which greatly enhances porewater exchange and that drives this elevated internal nutrient loading. The mechanism is driven by methane (CH4) ebullition from the sediment. As CH4 and bubble emissions occur in significant quantities within aquatic sediments worldwide, the CH4-induced transport becomes of global significance with far-reaching implications. The process potentially reduces the sediment residence time of nutrients, therefore increasing long-term and regional nutrient availability. Goal: While the presence of high levels of CH4 in porewaters is a consequence of eutrophication, eutrophication is, ironically, also a result of high CH4 concentrations in the porewater - thus providing an important feedback loop for self-sustained eutrophication. The goal is therefore, to understand driving forces of porewater exchange at the sediment surface as well as understand the implications of the presence of high CH4 concentrations on internal nutrient loading and sustained eutrophication. Approach: We will investigate the CH4- enhanced porewater exchange magnitude and dominant pathways under various forcing through laboratory testing, in situ observations and modeling exercises. The insights gained will define the key drivers of this exchange within natural waters. The results of this work will significantly impact our views on sediment processes as well as the understanding of biogeochemical cycles in aquatic systems on local, regional and global scales.