Our studies of turbulence in neutral fluids were carried out with explicit reference to the presumed importance of turbulence for the feeding process of aquatic micro-organisms. For these studies we had initially one database at our disposal, where the motions of many small polystyrene particles were followed, where these particles could be used as representing aquatic micro-organisms. These results were obtained by experimental studies at the Risø National Laboratory in Denmark. As a consequence of the success of the first investigations, we were approached by colleagues from Italy, giving us access to related simulation results from some of the largest numerical simulations of turbulent flows carried out today. These results were obtained by direct numerical solutions of the Navier-Stokes equation. The parameter range of these two datasets supplements those from the laboratory, by having a Reynolds number approximately twice as large. Although, of course, also the simulation data have their limitations, we were nonetheless able to provide estimates with unprecedented accuracy of, for instance, the turbulent particle fluxes to a perfectly absorbing spherical surface.