The MOBYDICK cruise will investigate end-to-end food webs in contrasted types of ecosystems in the Southern Ocean, near Kerguelen Islands: a ‘Low Biomass Low Export’ (LBLE) and a ‘High Biomass Low Export’ (HBLE) ecosystem, following the biogeochemical nomenclature. The cruise takes place from 18 February to 28 March 2018 and will depart and return from and to La Réunion Island.. The duration of the cruise is 38 days with 22 days on site, and 36 scientists will participate. The strategy is based on 3 repeated samplings (~10 days interval) of 2 contrasted stations (M2 and M4) and additional single samplings of 2 intermediate stations (M1 and M3). Station M2 is located in high–production iron fertilized waters above the Kerguelen plateau, and station M4 is located in low-production HNLC waters.