Description: AB: The methane seepage area off West Spitzbergen, which was first discovered in 2008, is reported to feature more than 250 gas bubbles release sites in water depth between 150 and 400 m. Because the depth zone overlaps with the boundary of gas hydrate stability and since this area has experienced a warming of the northward-flowing West Spitzbergen current by 1°C over the last 30 years, it has been speculated that the gas seepage is connected to recent gas hydrate dissociation. However, so far comprehensive biogeochemical studies, which could support this hypothesis, are lacking. In August 2011, we will conduct an expedition with the German RV Poseidon to explore the seafloor and water column in the vicinity of the gas seeps to search for physical, geochemical, biological, and geological characteristics that could provide information about the persistence of the gas seepage. In case the gas venting is caused by recent gas hydrate dissociation, we expect to find rather virgin sediments with respect to common cold-seep characteristics such as methanotrophic activity and the presence of chemosynthetic organisms and authigenic carbonates; whereas a full establishment of these features would support the idea of a long-lasting process. Anomalies in porewater characteristics provide further information about gas hydrate formation/dissociation dynamics. We will present preliminary results from the RV Poseidon expedition to provide fresh insights into this exciting research area. Data will includ