The control of transport due to electrostatic turbulence is investigated using test-particle simulations. We show that a barrier for the transport, that is, a region where transport is reduced, can be generated through the randomization of phases of the turbulent field. This corresponds to the annihilation of coherent structures which are present at all scales, without actually suppressing turbulence. When the barrier is active, a flux of particles towards the center of the simulation box is present inside the region where the barrier is located.