Bioturbation may affect benthic DOC fluxes in several ways. Bioturbation could enhance DOC oxidation (by microbial assemblage and benthic organisms), which leads to higher CO2 production and to smaller DOC fluxes. Redox oscillation produced by bioturbation could also affect benthic DOC fluxes, by releasing sorbed organic carbon and then enhancing DOC oxidation. However, sediment reworking during burrow construction and maintenance, and the increase in exchange area produced by burrows, could result in an enhancement of benthic DOC fluxes. Indeed, our results showed that N. granulata shifts the magnitude and direction of DOC benthic flux, which is toward sediment in non-bioturbated sites but is released to water column when N. granulata is present in both mudflat and saltmarsh zones. This stimulation effect was higher in mudflats than in saltmarshes, where possibly was highly stimulated DOC oxidation by heterotrophic bacteria in the rhizosphere. This leads to a smaller enhancement of benthic DOC fluxes in spite of the effect of sediment reworking, and to a higher effect of stimulation of CO2 fluxes, which is consistently with our results.