We analyze the collective behavior of hydrodynamically coupled molecular
motors. We show that the local fluxes induced by motors displacement can induce
the experimentally observed bidirectional motion of cargoes and vesicles. By
means of a mean--field approach we show that sustained oscillations as well as
bistable collective motor motion arise even for very large collection of
motors, when thermal noise is irrelevant. The analysis clarifies the physical
mechanisms responsible for such dynamics by identifying the relevant coupling
parameter and its dependence on the geometry of the hydrodynamic coupling as
well as on system size. We quantify the phase diagram for the different phases
that characterize the collective motion of hydrodynamically coupled motors and
show that sustained oscillations can be reached for biologically relevant
parameters, hence demonstrating the relevance of hydrodynamic interactions in
intracellular transport