In solutions of the charged semirigid biopolymer hyaluronic acid in salt-free conditions, the diffusion coefficient D-NSE measured at high transfer momentum q by neutron spin echo is more than an order of magnitude smaller than that determined by dynamic light scattering, D-DLS. This behavior contrasts with neutral polymer solutions. With increasing salt content, D-DLS approaches D-NSE, which is independent of ionic strength. Contrary to theoretical expectation, the ion-polymer coupling, which dominates the low q dynamics of polyelectrolyte solutions, already breaks down at distance scales greater than the Debye-Huckel length.