In recent decades, the Eurasian Basin of the Arctic Ocean has undergone remarkable variations as part of the large-scale environmental changes facing the planet. The Fram Strait connects the Arctic Ocean to the North Atlantic, and provides the main gateway for water exchange between the Arctic and the global oceans. Two major current systems are present in Fram Strait: the West Spitsbergen Current (WSC) carries Atlantic water northwards, and the East Greenland Current (EGC) brings cold Arctic waters and ice southwards (Fig 1 and 2). The proximity of these two distinct current systems creates a valuable opportunity for studying differences in microbial community composition across strong gradients of temperature and ice cover. Here we present a first preliminary investigation of both free-living and particle-associated pelagic bacterial communities in the upper water column across a longitudinal transect of the entire Fram Strait, conducted during RV Polarstern expedition PS85 (ARK-XXVIII/2) in June 2014
