Filippo de Lillo
Department of Physics, University of Turin, Italy

Clustering of gyrotactic algae in a turbulent ocean

Many one-celled algae which compose phytoplankton are able to swim. Some of them have simple orientation mechanisms leading them against gravity, away from the dark bottom of the ocean, towards light. A standard mechanistic model allows to account for several experimental observations as resulting from the balance between fluid torque and directed vertical motion, the so-called gyrotaxis. We will discuss some analytical and numerical results on how fluid turbulence affects the clustering of gyrotactic algae, producing small scale patchiness and dissolving large scale formations.