INFLUENCE OF DISTINCT WATER MASSES ON ORGANIC CARBON CONSUMPTION ACROSS THE SOUTHERN EAST CHINA SEA SHELF ECOSYSTEM

The southern East China Sea (ECS) is characterized by four distinct water masses: coastal water, Taiwan warm current water, upwelling water, and Kuroshio water. These water masses vary in their biogeochemical properties, significantly influencing the region's nutrient dynamics and planktonic processes. Nitrate concentrations were found to be highest in coastal water, followed by upwelled water, Taiwan warm current water, and lowest in Kuroshio water. Distribution patterns of chlorophyll a (Chl a) and particulate organic carbon (POC) closely reflected this nitrate gradient, with the highest levels in coastal water and the lowest in Kuroshio water. Plankton community respiration (CR), which reflects organic carbon consumption, exhibited similar patterns, showing the highest rates in coastal water, intermediate levels in upwelled and Taiwan warm current waters, and the lowest rates in Kuroshio water. A multiple linear regression analysis between plankton CR, POC, and bacterial production was conducted to further investigate the relationships driving carbon cycling in these water masses. The results suggest that coastal and upwelling regions of the southern ECS play a critical role in organic carbon consumption, likely driven by nutrient availability, with implications for carbon flux and ecosystem function across this dynamic shelf region.

Presentation Preference: Poster

Primary Presenter: Chung-Chi Chen, National Taiwan Normal University (ccchen@ntnu.edu.tw)

Authors:

Gwo-Ching Gong, Institute of Marine Environment and Ecology, National Taiwan Ocean University  (gcgong@mail.ntou.edu.tw)

Fuh-Kwo Shiah, Research Center for Environment Changes, Academia Sinica, NanKang  (fkshiah@rcec.sinica.edu.tw)