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 of great scientific significance for understanding the carbon sink pattern in the coastal ocean. The concentrations of total organic carbon (TOC) and total nitrogen (TN) and their isotopic compositions (δ13CTOC and δ15NTN) were determined in surface sedi...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-09-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2023.1234116/full |
| _version_ | 1827815337486188544 |
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| author | Junwen Wu Junwen Wu Jisheng Chen Cui Wang Xiuli Yan Xijie Yin Qian Liu |
| author_facet | Junwen Wu Junwen Wu Jisheng Chen Cui Wang Xiuli Yan Xijie Yin Qian Liu |
| author_sort | Junwen Wu |
| collection | DOAJ |
| description | The source apportionment of organic carbon is of great scientific significance for understanding the carbon sink pattern in the coastal ocean. The concentrations of total organic carbon (TOC) and total nitrogen (TN) and their isotopic compositions (δ13CTOC and δ15NTN) were determined in surface sediments and sediment cores (Y3 and Y5) collected in the eastern Guangdong coast (EGDC) during spring, summer and winter cruises in 2021, in order to determine the distribution and source of sedimentary organic matter. Spatially, TOC and δ13CTOC distributions in the EGDC have contrasting patterns; TOC concentrations decreased and δ13CTOC values increased with distance offshore. Higher TOC concentrations and enriched δ13CTOC were observed in the marine aquaculture area off EGDC. The measured values of δ13CTOC, δ15NTN and the C/N ratio constrained the two dominant sources of organic matter, marine and terrestrial material, in the EGDC. Using a two end−member mixing model, we estimated the proportion of marine organic matter to be 74 ± 20% in spring, 74 ± 16% in summer and 75 ± 12% in winter, respectively. This suggests in situ production of marine phytoplankton dominated the organic carbon pool (average=~74%) in the EGDC sediment. These consistent marine organic matter contributions are also observed in sediment cores, with proportions averaging 59 ± 5% in core Y3 and 66 ± 4% in core Y5. The observed variations in biogeochemical proxies in sediments are thus mainly caused by differing relative contributions of marine and terrestrial organic matter. Additionally, the high TOC inventory in the marine aquaculture area indicates increased carbon storage and carbon fixation capacity compared to the other areas investigated. Overall, this study establishes a background carbon database in the coastal environment that can be used in future studies of blue carbon to achieve carbon neutrality in China. |
| first_indexed | 2024-03-11T23:58:47Z |
| format | Article |
| id | doaj.art-07b3d3924d284ca1ab1dcd6e44edc737 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-03-11T23:58:47Z |
| publishDate | 2023-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-07b3d3924d284ca1ab1dcd6e44edc7372023-09-18T05:48:23ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452023-09-011010.3389/fmars.2023.12341161234116Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15NJunwen Wu0Junwen Wu1Jisheng Chen2Cui Wang3Xiuli Yan4Xijie Yin5Qian Liu6Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention & Institute of Marine Sciences, Shantou University, Shantou, ChinaSouthern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, ChinaGuangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention & Institute of Marine Sciences, Shantou University, Shantou, ChinaThird Institute of Oceanography, Ministry of Natural Resource, Xiamen, ChinaGuangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention & Institute of Marine Sciences, Shantou University, Shantou, ChinaThird Institute of Oceanography, Ministry of Natural Resource, Xiamen, ChinaFrontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, ChinaThe source apportionment of organic carbon is of great scientific significance for understanding the carbon sink pattern in the coastal ocean. The concentrations of total organic carbon (TOC) and total nitrogen (TN) and their isotopic compositions (δ13CTOC and δ15NTN) were determined in surface sediments and sediment cores (Y3 and Y5) collected in the eastern Guangdong coast (EGDC) during spring, summer and winter cruises in 2021, in order to determine the distribution and source of sedimentary organic matter. Spatially, TOC and δ13CTOC distributions in the EGDC have contrasting patterns; TOC concentrations decreased and δ13CTOC values increased with distance offshore. Higher TOC concentrations and enriched δ13CTOC were observed in the marine aquaculture area off EGDC. The measured values of δ13CTOC, δ15NTN and the C/N ratio constrained the two dominant sources of organic matter, marine and terrestrial material, in the EGDC. Using a two end−member mixing model, we estimated the proportion of marine organic matter to be 74 ± 20% in spring, 74 ± 16% in summer and 75 ± 12% in winter, respectively. This suggests in situ production of marine phytoplankton dominated the organic carbon pool (average=~74%) in the EGDC sediment. These consistent marine organic matter contributions are also observed in sediment cores, with proportions averaging 59 ± 5% in core Y3 and 66 ± 4% in core Y5. The observed variations in biogeochemical proxies in sediments are thus mainly caused by differing relative contributions of marine and terrestrial organic matter. Additionally, the high TOC inventory in the marine aquaculture area indicates increased carbon storage and carbon fixation capacity compared to the other areas investigated. Overall, this study establishes a background carbon database in the coastal environment that can be used in future studies of blue carbon to achieve carbon neutrality in China.https://www.frontiersin.org/articles/10.3389/fmars.2023.1234116/fullterrestrial organic carbonδ13CC/N ratiomarine sedimenteastern Guangdong coast |
| spellingShingle | Junwen Wu Junwen Wu Jisheng Chen Cui Wang Xiuli Yan Xijie Yin Qian Liu Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15N Frontiers in Marine Science terrestrial organic carbon δ13C C/N ratio marine sediment eastern Guangdong coast |
| title | Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15N |
| title_full | Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15N |
| title_fullStr | Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15N |
| title_full_unstemmed | Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15N |
| title_short | Constraining the origin of sedimentary organic matter in the eastern Guangdong coast of China using δ13C and δ15N |
| title_sort | constraining the origin of sedimentary organic matter in the eastern guangdong coast of china using δ13c and δ15n |
| topic | terrestrial organic carbon δ13C C/N ratio marine sediment eastern Guangdong coast |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2023.1234116/full |
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