The transatlantic Helmholtz Research School for Ocean System Science and Technology (HOSST) aims to train the next generation of researchers in the key scientific areas critical for responsible resource utilization and management of the ocean with special emphasis on their “local ocean” – the North Atlantic. HOSST pools the complementary expertise of the Helmholtz Centre for Ocean Research Kiel (GEOMAR), the Christian-Albrechts-Universität zu Kiel, the Dalhousie University and the Halifax Marine Research Institute (HMRI) and is organized around three themes which encompass key sensitivities of the North Atlantic to external forcing and resource exploitation: 4D Ocean Dynamics, Ecosystem Hotspots, and Seafloor Structures. Interactions within and between these themes regulate how the ocean system responds to both anthropogenic and natural change.