Biomarker Records of Phytoplankton Productivity and Community Structure Changes in the Central Yellow Sea Mud Area During the Mid-Late Holocene

• Published in: Journal of Ocean University of China 2013-12, Vol.12 (4), p.639-646
• Main Authors: Zhao, Xiaochen, Tao, Shuqin, Zhang, Rongping, Zhang, Hailong, Yang, Zuosheng, Zhao, Meixun
• Format: Article
• Language: English
• Subjects: Biomarkers; Community ecology; Community structure; Cores; Earth and Environmental Science; Earth Sciences; Holocene; Marine; Marine ecology; Meteorology; Ocean currents; Oceanography; Phytoplankton; Plankton; Productivity; 东亚冬季风; 中晚全新世; 植物生产力; 泥质区; 生物标志物; 种群; 结构变化; 黄海暖流
• ISSN: 1672-5182; 1993-5021; 1672-5174
• DOI: 10.1007/s11802-013-2271-0

The Yellow Sea （YS） environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current （YSWC）, the East Asian Winter Monsoon （EAWM） and the Kuroshio Current （KC）. We report marine biomarker records of brassicasterol, dinosterol and C37 alkenones in core ZY1 and core ZY2 from the South Yellow Sea （SYS） to reconstruct the spatial/temporal variations and possible mechanisms of phytoplankton primary productivity and community structure changes during the Mid-late Holocene. The contents of the corresponding biomarkers in the two cores are similar, and they also reveal broadly similar temporal trends. From 6kyr to 3kyr, the biomarker contents in the two cores were relatively low with small oscillations, followed by a distinct increase at about 3 kyr indicating productivity increases caused by a stronger EAWM. The alkenone/brassicasterol ratio （A/B） is used as a community structure proxy, which also showed higher values in both cores since 3 kyr, indicating increased haptophyte contribution to total productivity. It is proposed that the YS community structure has been mainly influenced by the YSWC, with stronger YSWC influences causing an increase in haptophyte contribution since 3 kyr. Some differences of the biomarker records between ZY2 and ZYI suggest spatial variations in response to YSWC and KC forcing. When the KC was intensified during the periods of 6-4.2kyr and 1.7-0kyr, the YSWC extended eastward, exerting more influence on core ZY1. On the other hand, when the KC weakened during 4.2-1.7 kyr, the YSWC extended westward, exerting more influence on the ZY2.