@article{oai:nagoya.repo.nii.ac.jp:00023072, author = {Lei, Gao and Li, Daoji and Ishizaka, Joji}, issue = {8}, journal = {Journal of Geophysical Research Biogeosciences}, month = {Aug}, note = {Seven cruises were conducted in the Changjiang (Yangtze River) Estuary and the adjacent western East China Sea (ECS) from 2010 to 2012 to study the seasonal variations of δ13C and δ15N in suspended organic matter. In addition, two cruises in the northeastern ECS in July 2011 and in Tsushima Strait in July 2012 were conducted to evaluate the distribution patterns of these isotopes over the entire Changjiang transport pathway. In summer, the surface δ13C was lowest in the Changjiang Channel, increasing from land to sea, reaching highest values in the central ECS, and then decreasing and remaining relatively constant. In winter, the surface δ13C in the western ECS showed lower values with less variation in general. At most stations, δ13C increased from the sea surface to the seabed, reflecting the degradation of sinking organic matter; however, these trends could be changed in the summer by surface phytoplankton accumulation. Combining data from all the Changjiang Estuary and western ECS cruises revealed that when the suspended particulate matter (SPM) was > 135 mg/L, the δ13C values were fairly constant (−24.5‰ to −20.5‰); when the SPM was < 135 mg/L, the δ13C values showed much greater variability (−28.4‰ to −16.6‰). The surface δ15N also showed generally higher values in the central ECS in summer and lower values in winter. The seasonal variations of δ13C and δ15N were largely attributed to the SPM composition change, i.e., more phytoplankton cells in the summer whereas more resuspended sediment particles were present in winter.}, pages = {1717--1737}, title = {Stable isotope ratios of carbon and nitrogen in suspended organic matter: Seasonal and spatial dynamics along the Changjiang (Yangtze River) transport pathway}, volume = {119}, year = {2014} }