This dataset was collected during the iMAR cruise “The Integrated assessment of the distribution of Vulnerable Marine Ecosystem along the Mid-Atlantic Ridge (MAR) in the Azores region”, that took place aboard the Research Vessel Pelagia of the Royal Netherlands Institute for Sea Research (NIOZ) between May 19^th and June 2^nd 2021. The iMAR cruise aimed to evaluate the role of the MAR in shaping latitudinal and trans-Atlantic patterns in deep-sea biogeography, connectivity and assemblages of deep-sea megafauna. This expedition was funded by the SEA OCEANS program of Eurofleets+ and the H2020 European project iAtlantic, and was led by the University of the Azores (Portugal) in collaboration with the Hydrographic Institute and University of Porto (Portugal), the University of Aarhus (Denmark), the National Oceanography Center (United Kingdom), GEOMAR (Germany), the University Museum of Bergen (Norway), the PP Shirshov Institute of Oceanology (Russia), and the University of Vale do Itajaí (Brazil).

The deep-sea benthic communities were mapped using the NIOZ towed camera system. The Hopper system generated a series of high-definition video transects in each area explored, starting from the deepest point (set at 1,200 m approx.) and moving upwards towards the seamount or ridge summit (700 m to 300 m depth). During the iMAR cruise, 22 stations for Hopper video transects were performed (Table 1), mainly in the North portion of the MAR inside the Exclusive Economic Zone around the Azores, which produced approximately 54 hours of bottom time, along 48 km of seafloor.