The open ocean is the largest biome on Earth, yet it is the least protected. A major obstacle to its conservation lies in the fine-grained understanding of how marine organisms are affected by the ocean dynamics. In the last decades remote sensing and bio-logging drastically increased our understanding to how phytoplankton (that can be observed from space as ocean color) and large marine animals (that can be followed with sensors directly attached to them) responds to oceanic turbulence down to the mesoscale (few weeks-months, 10-100 km). A major knowledge gap still concerns the so-called "intermediate trophic levels" (ITLs, i.e. zooplankton and micronekton,) and how mesoscale currents (such as fronts and eddies) affect them. This is the focus of the MECODIHR project. The project uses an unprecedented combination of remote-sensing, and modelling on a multi-disciplinary in-situ database collected in the North-West Atlantic to identify patterns in the distribution of ITLs, relate them to physical structures and biogeochemical observations and make hypotheses about why such relationships arise. High-resolution state-of-the-art modelling allows to test the validity of the formulated hypotheses, clarify the mechanisms behind observed co-localisations and expand the extent of findings. High resolution in-situ measurements and modelling allows to approach how submesoscale dynamics (and its inter-seasonal variability) affect the distribution of ITLs. The MECODIHR results, acquired between the two multidisciplinary highly-reknown oceanographic laboratory of the University of Washington (outgoing phase : 2 years) and the Université de Bretagne Occidentale (incoming phase : 1 year), will provide critical information for open ocean conservation. The MECODIHR project will also train Dr. Della Penna with a rare combination of skills (including scientific, communicative, technical and transferable skills) that are fundamental to face the future challenges of marine sciences.