  We investigate the Mott effect for heavy quarkonia due to Debye screening of
the heavy quark potential in a plasma of massless quarks and antiquarks. The
influence of residual color correlation is investigated by coupling the light
quark sector to a temporal gauge field driven by the Polyakov loop potential.
This leads to an increase of the Mott dissociation temperatures for quarkonia
states which stabilizes in particular the excited states, but has marginal
effect on the ground states. The temperature dependence of binding energies
suggests that the dissciation of the charmonium (bottomonium) ground state by
thermal activation sets in at temperatures of 200 MeV (250 MeV).
