δ13C, δ15N and TOC/TN as indicators of the origin of organic matter in sediment samples from the estuary of a tropical river

MARINE POLLUTION BULLETIN

卷:172

Article

Carneiro, Luanna Maia¹  Zucchi, Maria do Rosario^1,2  de Jesus, Taise Bomfim³  Junior, Jucelino Balbino da Silva¹  Hadlich, Gisele Mara¹ 

[1] Univ Fed Bahia, Inst Geociencias, Programa Posgrad Geoquim Petr & Meio Ambiente, Salvador, BA, Brazil

[2] Univ Fed Bahia, Inst Fis, Lab Isotopos Estaveis, Salvador, BA, Brazil

[3] Univ Estadual Feira de Santana, Dept Ciencias Exatas, Feira De Santana, BA, Brazil

关键词: Tropical estuary;    Core sediments;    Origin of organic matter;    Isotopes;   

DOI  :  10.1016/j.marpolbul.2021.112857

来源: Elsevier

【 摘 要 】

The present study aimed to determine the total organic carbon (TOC), total nitrogen (TN), the carbon-nitrogen ratio (TOC/TN), carbon isotope (delta C-13), and nitrogen isotope (delta N-15) in five sediment cores collected from up-stream to downstream of the Rio Serinhaem estuary, State of Bahia, Northeast Brazil, in order to investigate the origin of the deposited organic matter (OM).Significant positive correlation was found between TOC and NT (r(s) = 0.75); TOC/TN and TOC (r(s) = 0.64); delta N-15 and TOC (r(s) = 0.72); and delta N-15 and TOC/TN (r(s) = 0.63). The values of delta C-13 and delta N-15 found are characteristic of terrestrial sources. The TOC/TN ratio confirmed the data found for delta C-13 and delta N-15, which recorded the origin of organic matter from terrestrial C3 type plants. Upstream of the estuary, the highest means of TOC/TN were found (T1 = 36.9 and T2 = 24.4), as reflected by the increase in TOC content or reduction in TN. The OM along the estuary is predominantly from plants with a C3 photosynthetic pattern, indicating that the Serinhaem River estuary is considered a relatively well-preserved environment.

【 授权许可】

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