title: Linking optical properties of dissolved organic matter to multiple processes at the coastal plume zone in the East China Sea.
abstract: Because of the significance in photosynthesis, nutrient dynamics, trophodynamics and biological activity, dissolved organic matter (DOM) is important to the microbial community in the coastal plume zone. In this study, we investigated the hydrodynamic processes, photodegradation and biodegradation of DOM at the Yangtze River plume in the East China Sea through analyzing water quality and optical properties of DOM. Surface water samples were collected to examine water quality and fluorescence properties of fluorescent dissolved organic matter (FDOM). The results indicated that dilution was the key factor in the multiple processes, and the mixing process gradually increased from nearshore to offshore in coastal water. Four components of FDOM representing humic-like substances (C1 & C4) and protein-like substances (C2 & C3) were identified, and all components showed nearly conservative behaviors. Protein-like substances were more mutable compared to humic-like substances. The photodegradation of humic-like substances caused brown algae blooms to some extent. The molecular weight of humic substances gradually decreased along the mixing process. FDOM in the plume zone was both of terrigenous and autochthonous origins, and the characteristic of terrigenous origin was obvious compared to that of autochthonous origin.
authors.affiliation: Key Laboratory of Yangtze River Water Environment of the Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. qhhuang@tongji.edu.cn.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
authors.forename: Jianfu
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Yangtze River Water Environment of the Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. qhhuang@tongji.edu.cn.
authors.forename: Penghui
authors.initials: P
authors.lastname: Li
authors.affiliation: Key Laboratory of Yangtze River Water Environment of the Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. qhhuang@tongji.edu.cn.
authors.forename: Qinghui
authors.identifier: http://orcid.org/0000-0001-5770-6694
authors.initials: Q
authors.lastname: Huang
mesh_terms: D002681:China; D005453:Fluorescence; D006812:Humic Substances / Q000032:analysis / Q000528:radiation effects; D009792:Oceans and Seas; D010782:Photolysis; D045483:Rivers; D013050:Spectrometry, Fluorescence; D014873:Water Pollutants / Q000032:analysis / Q000528:radiation effects; D060753:Water Quality
chemical_list: D006812:Humic Substances; D014873:Water Pollutants