The Southern Ocean is regarded as a key region in understanding the role of biogeochemical cycling on the variation of global climate. Although this Ocean is characterized by HNLC (High Nutrient Low Chlorophyll) conditions, areas of high biomass do occur including the Kerguelen-Heard one. These bloom occurrences are attributed to natural fertilization due to micronutrient inputs from the Kerguelen archipelago and plateau, which is therefore an ideal laboratory to study the mechanisms of natural iron fertilization in the Ocean. Better defining these mechanisms was the main aim of the KErguelen Ocean and Plateau compared Study project (KEOPS). For this purpose, a good understanding of the parameters forcing the biological activity, the particle dynamics and advection processes in this area was required. Two cruises were realized onboard R/V Marion-Dufresne (IPEV): KEOPS 1 at the end of summer (19 January to 13 February 2005) and centered on the plateau and KEOPS 2 (10 October–20 November 2011) at the beginning of spring and which track was extended to the fertilized plume in the wake of Kerguelen.