Surface seawater from Drake Passage, Southern Ocean

The Southern Ocean (SO) is structured by several oceanographic fronts, such as the Antarctic Polar Front (APF) and the Southern Boundary of the Antarctic Circumpolar Current (sBdyACC), which induce pronounced changes in seawater physicochemical characteristics and are considered barriers to the dispersal of some organisms. However, high-resolution studies are needed to understand their effects on microbial diversity, particularly across the Drake Passage, characterized by the shortest Antarctic/Subantarctic distance, creating sharp environmental gradients. Here, we evaluated the effect of two major oceanic fronts of the SO on the distribution of prokaryotic and microeukaryotic communities across the Drake Passage between Subantarctic Patagonia and the Weddell Sea.