The dynamics of self-propelled micron-size particles is affected by the fluid in which they are suspended, since it interferes with the internal mechanisms which generate their propulsion. These active objects also modify the properties of the fluid they are embedded in due to the generation of active stresses. Since these liquids are intrinsically out of equilibrium, a dynamical study of the mesoscopic structures these materials develop is required. I will discuss a simplified computational approach which resolves individual self-propelled motion. I will analyze the dynamic cooperativity in suspensions of self-phoretic colloids in (quasi)-2D configurations. I will consider how the the phoretic mobility, which accounts effectively for the colloid-solute interactions, determines the emergent phases in such suspensions, leading from a cluster phase to a jammed state. The computational study shows that the cluster size distribution follows an exponential behaviour, with a characteristic size growing linearly with the colloid activity, while the density fluctuations grow as a power-law with an exponent depending on the cluster fractal dimension. The study singles out the role of hydrodynamic interactions in the development of such structures, showing that their effect is to work against cluster formation.