I will discuss the evolution of hydrodynamic fluctuations for QCD matter below T_c in the chiral limit. The theoretical description is ordinary hydrodynamics at long distances and superfluid-like at short distances. The latter is represented by pions (the Goldstone modes), reflecting the broken SU(2)_L x SU(2)_R symmetry. The superfluid degrees of freedom contribute to the transport coefficients of the ordinary theory at long distances. This determines the leading dependence of some transport parameters of QCD on the pion mass. I will make some comments on the predictions of this computation near the O(4) critical point.