The objective of MOBYDICK is to study the links that exist between the biological pump of carbon and the food web structure. To address this issue MOBYDICK proposes a novel approach by considering the entire food web from microbes to top predators and by investigating the hitherto poorly studied relationships between biogeochemical fluxes and biodiversity. The dataset required to test the hypotheses proposed in MOBYDICK will be acquired during  an oceanographic campaign off Kerguelen Island (Southern Ocean). In this well-documented area, two contrasted ecosystems ‘Low Biomass Low Export’ and ‘High Biomass Low Export’ coexist. MOBYDICK has gathered an international consortium to carry out a wide range of techniques for the determination of stocks, fluxes and biodiversity, which are rarely utilized simultaneously. The results will represent a milestone for fundamental knowledge, but they will also provide essential information for the sustainable management of these vulnerable ecosystems.

The THEMISTO program joined MOBYDICK to realize acoustic measurements that will provide information on (i) the nychtemeral vertical migration of numerous organisms (ii) horizontal/vertical structuring of taxonomic/functional groups and (iii) trophic interactions. These informations will give us some insights on the vertical Carbon flux.

Onboard Marion Dufresne for THEMISTO: Anna Conchon (LOCEAN, UPMC), Jérémie Habasque (LEMAR, IRD), Cédric Cotté (LOCEAN, MNHN)