In the final part of our cruise (14-19 December 2022) we started a box core sampling strategy on the pockmark field in order to describe seafloor textures, check for the presence of cold-water corals and characterise macro- and meiofauna diversity. We performed, in total, 35 deployments in water depths of 400 – 1000 metres. We aimed at regions surrounding the rims of pockmarks and found that sedimented seafloor was always dominant, usually with a 5-6 cm of organic matter on the surface. We also sampled over geological features that looked like linear crests formed in between pockmarks and finally found abundant coral rubble that suggested that these could be coral mounds. At last, on one of these features (16 December), we captured a live black coral colony that supported this theory and made us very happy. It was a good reward after hours of mud sieving, conducted around the clock for three days by two enthusiastic teams of very young scientists.
We finished our sampling activities on 19 December, after completing the sediment sampling procedure for on board experiments and completing high resolution bathymetry mapping of the entire study area. We set sail to Rio de Janeiro and spent the time in transit organising samples and data. We had massive support from our Navy friends who processed long hours of MBES, CTD and current speed data (L-ADCP) just in time for us to pack up. We are greatly indebted to them. And we also celebrated the “Saylor’s Day” (13 December) with “churrasco & samba” on board. On our last night there was a seminar, which gave us a chance to present the iAtlantic and Petrobras activities and discuss the progresses made during this cruise.
