The dissolved oxygen in the ocean is undergoing deoxygenation under the multiple pressures of human activities and climate warming. However, the uncertainties regarding the generation mechanisms and assessment of ocean deoxygenation need be considered. 

The group developed the oxygen isotope analysis technology of oceanic dissolved oxygen which were applied to study estuaries, marginal seas, and the deep seas. In coastal estuaries the water column and sediments consume oxygen. During low-oxygen periods, the water column is the primary culprit, accounting for over 70% of the oxygen loss. In the South China Sea's continental slope, oxygen isotopes are used to measure oxygen depletion in subsurface waters. There is a clear link between oxygen isotope enrichment and the recycling of nutrients. In the deep North Pacific oxygen consumption in the water column is slower than expected, with notable isotopic fractionation effects.

Based on Big data, a new model of "spatial data interpolation + Monte-Carlo" was adopted, which reduced the uncertainty of the oxygen minimum zone by two-thirds. By this high-precision model, the emergence time and rate of future ocean deoxygenation signals were predicted.