Organic carbon (OC), including dissolved and particulate forms, represents the most reactive carbon pool on earth. OC undergoes intense physical and biochemical alteration/modification during its transport along the land-ocean continuum. The composition, sources, biogeochemical cycling, and environmental fate of OC in the estuaries and coastal oceans have always been intriguing to marine biogeochemists¹. Besides, the composition of coastal OC is also highly related to anthropogenic activities, and it remains uncertain how and to what extent anthropogenic influences may be altering OC dynamics in the estuarine and ocean margin regions. Despite decades of efforts, we still have a very limited understanding of biogeochemical processes in estuaries and coasts, especially at the molecular level. High-resolution mass spectrometry is widely used to study organic matter’s molecular composition because of its unique advantages^2,3. However, the molecular results from different groups are still poor comparable. Hence, Professor HE Ding's group is committed to integrating molecular fingerprint data (mainly based on the state-of-the-art ultra-high-resolution mass spectrometry) from different natural environments around the world, such as rivers, lakes, reservoirs, soils, and especially oceans, and constructing a molecular fingerprint “big database” for decoding the complex biogeochemical cycling. They aim to

(1) assess molecular signatures in different environments;

(2) extract associations between different environments by using big data techniques, including deep learning methods;

(3) use databases to predict the fate of organic matter in different environments; and

(4) use big data results to drive the development of case studies in the future. Ultimately, they believe that the big data results will provide a basis for future organic matter research directions.

[1] He, D.*, Ladd, S.N., Park, J., Sachs, J. P., Simoneit, B.R.T., Smoak, J. M., Jaffé, R. (2022). Carbon and hydrogen isotopes of taraxerol in mangrove leaves and sediment cores: Implications for paleo-reconstructions. Geochimica et Cosmochimica Acta, 324, 262-279.

[2] He, D.*, Li, P., He, C., Wang, Y., Shi, Q. (2022). Eutrophication and watershed characteristics shape changes in dissolved organic matter chemistry along two river-estuarine transects. Water Research, 214, 118196.

[3] Zhou, Y., Zhao, C., He, C., Li, P., Wang, Y., Pang, Y., Shi, Q., He, D.* (2022). Characterization of dissolved organic matter processing between surface sediment porewater and overlying bottom water in the Yangtze River Estuary. Water Research, 215, 118260.