To investigate the influence of scallop farming on the biogeochemical characteristics of colloidal organic matter (COM, 1 kDa-0.7 μm), surface and bottom seawater samples collected from a bay scallop mariculture area (MA) and its adjacent waters were size-fractionated and analyzed for absorption and fluorescence characteristics. Compared to inshore shallow water area and non-mariculture area (NMA), COM in MA exhibited the highest proportion of a