1. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China, Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, California 92683, Institute of Estuarine and Coastal Research, Zhongshan University, Guangzhou 510275, China, and Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong Special Administrative District, China