Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15N

The source apportionment of organic carbon is great scientific significance for understanding the sink pattern in coastal ocean. concentrations total (TOC) and nitrogen (TN) their isotopic compositions (δ 13 C TOC δ 15 N TN ) were determined surface sediments sediment cores (Y3 Y5) collected eastern Guangdong coast (EGDC) during spring, summer winter cruises 2021, order to determine distribution sedimentary matter. Spatially, distributions EGDC have contrasting patterns; decreased values increased with distance offshore. Higher enriched observed marine aquaculture area off EGDC. measured , C/N ratio constrained two dominant sources matter, terrestrial material, Using a end−member mixing model, we estimated proportion matter be 74 ± 20% 16% 75 12% winter, respectively. This suggests situ production phytoplankton dominated pool (average=~74%) sediment. These consistent contributions are also cores, proportions averaging 59 5% core Y3 66 4% Y5. variations biogeochemical proxies thus mainly caused by differing relative Additionally, high inventory indicates storage fixation capacity compared other areas investigated. Overall, this study establishes background database environment that can used future studies blue achieve neutrality China.