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| The identification of Lagrangian coherent structures provides a powerful conceptual framework for extracting key transport features from the velocity field at the ocean surface. When applied to satellite derived currents, this technique allows to track transport barriers and fronts induced by the mesoscale activity (i.e., interaction among vortices of ~100km size, so-called mesoscale eddies). By comparing these physical features to biological data, like phytoplanktonic community structure and distribution of top predators, mechanisms of biophysical interactions can be explored. Here I will focus on the role of transport barriers induced by horizontal stirring, which can create quasi-isolated water patches with lifetimes long enough for specific phytoplanktonic community to emerge. These fluid dynamical niches are organized as a patchwork of 100km contrasted environments, that are eventually mixed together, hinting regions where hotspots of biodiversity could be dynamically generated. Similarly, semi-enclosed eddy cores may constitute key region where high concentration of phytoplanktonic biomass is transferred to higher trophic levels, creating regions of special interests for foraging animals like elephant seals, frigatebirds, and whales. Tracking these regions of ecological importance is of key interest for focusing conservation efforts in the open ocean. |
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