Abstract: Benthic O₂ availability in aquatic systems plays an important role in biogeochemical processes crucial to the biology and ecology of benthic communities. In situ methods enable high-resolution measurements of solutes close to the bottom water, and their application to surface sediments has the potential to better define the links between oxygen and the unique biogeochemical phenomena occurring in these regions. The potential reaction of solute dynamics in the sediment was investigated by recording high resolution microprofiles of PO₄^3--P and NH₄⁺-N using an in situ sampler micro-peeper. The results suggested that continuous air/nitrogen microbubbles could significantly enhance NH₄⁺-N levels in the porewaters, and could be further enhanced with increasing temperature. Moreover,porewater PO₄^3--P levels were significantly lower under continuously bubbling air, but were not affected by continuously bubbling nitrogen. An obvious tendency for increasing PO₄^3--P levels was observed with the increasing temperature, similar to the NH₄⁺-N distribution. Typical input to the overlying water under low oxygen or nitrogen conditions was found to be 10.41-25.85 mg/(m²·d), whereas fluxes under aerobic conditions and CaO₂ addition (5 g/m²) were only -17.20-0.07 mg/(m²·d). PO₄^3--P release was found to be dependent on oxygen level and temperature. Under aerobic conditions, surface sediment might be considered an important sink of NH₄⁺-N and PO₄^3--P pollutants because of adsorption from overlying water. However, sediments could also inversely act as a source of pollutants by releasing dissolved nitrogen and phosphorus nutrients to bottom water in the case of hypoxia or higher temperature environment.