Dissolved organic carbon can alter coastal sediment phosphorus dynamic: Effects of different carbon forms and concentrations.

Autor: Ma SN; School of Marine Sciences, Ningbo University, Ningbo, 315832, China. Electronic address: mashuonan@nbu.edu.cn., Dong XM; School of Marine Sciences, Ningbo University, Ningbo, 315832, China. Electronic address: xumengd@gmail.com., Xu JL; School of Marine Sciences, Ningbo University, Ningbo, 315832, China. Electronic address: xujilin@nbu.edu.cn., Zhao CP; School of Marine Sciences, Ningbo University, Ningbo, 315832, China. Electronic address: 2201130087@nbu.edu.cn., Liu M; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China. Electronic address: 15827478943@163.com., Wang HJ; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China. Electronic address: wanghaijun@ynu.edu.cn., Jeppesen E; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China; Department of Ecoscience and WATEC, Aarhus University, Aarhus, 8000, Denmark; Sino-Danish Centre for Education and Research (SDC), University of Chinese Academy of Sciences, Beijing, 100190, China; Limnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, Ankara, 06800, Turkey; Institute of Marine Sciences, Middle East Technical University, 33731, Erdemli-Mersin, Turkey. Electronic address: ej@ecos.au.dk.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2025 Feb; Vol. 370, pp. 143914. Date of Electronic Publication: 2025 Jan 02.
DOI: 10.1016/j.chemosphere.2024.143914
Abstrakt: Coastal waters are receiving increasing loads of dissolved organic carbon (DOC), differing in structural complexity and molecular weights with potential different effects on the phosphorus (P) dynamics in these waters. This study conducted an in-situ investigation in Xiangshan Harbor, China, to explore the patterns of P release in response to DOC inputs. To further elucidate the underlying mechanisms behind the DOC-affected sediment P release, a two-month mesocosm experiment was undertaken with coastal sediment (Xiangshan Harbor) to which acetate, glucose, and humic acid (representing the fermentation product, the simple available carbon, and the refractory humic-like carbon sources, respectively) were separately added to the overlying water at dosages of 0, 5, 10, and 20 mg C L -1 . We found that: i) sediment P release showed a non-linear increase with DOC input, a pattern likely due to the diverse forms of DOC in coastal zones, which had varying impacts on P release; ⅱ) significant P release for labile DOC (acetate- and glucose-amended) treatments but retention for humic acid treatments, and the magnitude of P changes mainly depended on the amount of DOC addition; ⅲ) acetate and glucose shared similar P-release-promotion mechanisms, i.e., decreased dissolved oxygen, increased ppk genes in water, and increased P bacteria and alkaline phosphatase activity were the dominant factors behind the P release for both carbon sources, as indicated by piecewise structural equation modelling; ⅳ) humic acid-inhibitory effects on sediment P release, which likely reflect increasing "P-humic acid" complexes that favor P adsorption and sedimentation and form stable "humic acid-enzyme" complexes that reduce the catalytic activity of alkaline phosphatase. Our findings provide new understanding of relationships between loading of DOC with different form/concentration and sediment P dynamics in coastal areas.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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