(M)ass transport in Taylor-Couette and Poiseuille vortex flows has been experimentally investigated by dye injection, particle tracking and electrochemical techniques. An annular cavity has been built with an inner/outer radius ratio of 0.5, with a fixed outer cylinder and a rotating inner one. Without any axial flow, the standard Taylor-Couette flow was observed and the Sherwood number for radial dispersion measured. When a low axial flow rate was imposed (Re-a < 10), a mechanism for axial dispersion similar to the dispersion of a wave packet was drawn from visualization results.