We characterized dissolved organic matter (DOM;

We characterized particulate organic matter (POM) collected from both the surface (41 m and 200 m) and mesopelagic layers (500 m and 1000 m) in the western South China Sea. By using a shotgun proteomic approach, a total of 3035 proteins matching one or more peptides were detected from four POM samples, 505 of which were identified as high‐confidence proteins matching two or more peptides. Cyanobacteria was the largest contribu...