Environmental factors affecting regional differences and decadal variations in the buried flux of marine organic carbon in eastern shelf sea areas of China

• 作者: Qian Yang Keming Qu Shu Yang Yao Sun Yan Zhang Mingying Zhou
• 来源期刊: 海洋学报（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: Marine Chemistry
• 页码范围: 26-34
• 页数: 9页
• 语种: 英文

摘要

To characterize environmental factors controlling decadal-scale variations in the buried flux of marine organiccarbon ( BFCm ) in the eastern shelf sea areas of China (ECSS), four well preserved sediment cores collected fromthe central Yellow Sea mud (CYSM) area, the Yellow Sea Coastal Current (YSCC) area and the Changjiang River Estuary (CRE) were investigated in this study. In the CYSM, variations in BFCm were found to be dependent onvariations in primary productivity and to exhibit a cyclical trend possibly related to fluctuations in the Pacific Decadal Oscillation (PDO) and the East Asian winter monsoon index (EAWM). In the YSCC, BFCm likewise depends on primary productivity. Prior to the 1950s, variations in BFCm were similar to that of the EAWM. After the 1950s, BFCm increased rapidly and exhibited maximum values in the surface layer, consistent with an increasein primary productivity caused by the input of terrestrial nutrients associated with China's economic development. In the CRE, variations in BFCm were affected by several competing factors making it difficult to identify clear relationships between variations in BFCm and primary productivity. In contrast, long-term variability in BFCm is more similar to changes in the Changjiang River sediment load. Thus, it is speculated that the construction of dams along the Changjiang River may be the main cause of variations in BFCm in this area. Given the disproportionate effects of human activities on marine environments and decadal variations in BFCm in theECSS, careful attention should be paid to regional differences in organic carbon preservation and environmental changes lest estimates of these values be made imprecise or inaccurate.