Fatty acids and their carbon isotopes in surface sediments from the Pearl River Estuary and northwestern South China Sea


Tropical and subtropical rivers deliver large quantities of terrestrial organic carbon to the ocean, acting as a crucial part of the global carbon cycle, but little is known about the timescale and efficiency of their transport to and in the adjacent coastal sea. Here, we examined source-specific biomarker (normal fatty acids (n-FAs)) contents and isotope compositions in surface sediments in an alongshore transect southwestward from the Pearl River mouth. The C~28+30~ rather than other long-chain n-FAs were found to be the most representative for OC~terr~, and a plant wax mean residence time (MRT) of 3060 ± 90 yr was estimated in the Pearl River watershed from the ¹⁴C age of C~28+30~ n-FA in the river mouth sample. A four-source mixing model demonstrated that the mean burial efficiency of fossil and soil OC is 85% and 49%, respectively, indicating the refractory nature of fossil OC but a significant loss of soil OC due to remineralization during transport in the marine environment before final burial. Thus, the remineralization of soil OC in the tropical coastal sea may be an important CO₂ source.

DOI https://doi.org/10.1594/PANGAEA.925137
Related Identifier https://doi.org/10.1016/j.epsl.2021.116934
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.925137
Creator Wei, Bingbing ORCID logo; Mollenhauer, Gesine (ORCID: 0000-0001-5138-564X); Hefter, Jens ORCID logo; Kusch, Stephanie ORCID logo; Grotheer, Hendrik ORCID logo; Schefuß, Enno (ORCID: 0000-0002-5960-930X); Jia, Guodong ORCID logo
Publisher PANGAEA
Publication Year 2020
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Language English
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 3 datasets
Discipline Earth System Research
Spatial Coverage (111.350W, 21.250S, 113.810E, 22.710N)
Temporal Coverage Begin 2011-08-02T00:00:00Z
Temporal Coverage End 2017-10-24T00:00:00Z