ME4SURE · Are anthropogenic pollutants in Marine sediments a potential mEthane (CH4) SoURcE (ME4SURE)?

Current climate change and global warming with a continuous increase of methane (CH4) emissions will reshape life on Earth. Oceanic methane emissions are predominantly controlled by the coastal environments, which are confronted with intensifying inputs of various anthropogenic chemicals from human activities. Alarming new correlations have been found between this increased coastal pollution, especially discharges from wastewater treatment plants (WWTP), and CH4 emissions. However, without knowing the mechanism of influence of the anthropogenic chemicals on CH4 cycle in marine sediments, we might be underestimating CH4 into the atmosphere from polluted coastal environments and cannot mitigate these emissions. To move from correlation-based observations to a mechanistic- and experimental-based knowledge of CH4 production pathways in polluted coastal sediments it is necessary to apply multidisciplinary approaches. In this project it is achieved by a novel strategy through both field and experimental approach, where different disciplines: Compound-Specific Isotope Analysis, biogeochemistry, and microbial analysis are applied to provide separate line of to define the level of anthropogenic organic chemicals influence of CH4 emissions in coastal environment. I will investigate a representative polluted coastal area located in the Swedish West coast, which hosts the largest Scandinavian oil harbor (the primary petrochemical industry in Sweden), several streams debouch from agricultural areas, and the direct discharge of hundreds of chemicals from a WWTP. This project is the first step to improve our understanding on how much CH4 is produced in coastal areas affected by chemical pollution with global impact on the CH4 oceanic budget.