Dissolved PAHs in the Beibu Gulf and adjacent waters of the South China Sea: Physical and biochemical processes-driven distributional variations

Jingwen Shi; Mengyang Liu; Jiandong Ye; Fajin Chen; Xuke Chen; Yan Lin; Hongwei Ke; Minggang Cai

Ecotoxicology and Environmental Safety (Nov 2024)

Dissolved PAHs in the Beibu Gulf and adjacent waters of the South China Sea: Physical and biochemical processes-driven distributional variations

Jingwen Shi,
Mengyang Liu,
Jiandong Ye,
Fajin Chen,
Xuke Chen,
Yan Lin,
Hongwei Ke,
Minggang Cai

Affiliations

Jingwen Shi: Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen 361102, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
Mengyang Liu: State Key Laboratory of Marine Pollution, City University of Hong Kong, 999077, Hong Kong; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
Jiandong Ye: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
Fajin Chen: College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China
Xuke Chen: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
Yan Lin: School of Environmental Science and Engineering, Xiamen University of Technology, Xiamen 361024, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
Hongwei Ke: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
Minggang Cai: Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen 361102, China; College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Corresponding author at: College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.

Journal volume & issue: Vol. 286
p. 117208

Abstract

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Polycyclic aromatic hydrocarbons (PAHs) in semi-enclosed gulfs are influenced by physical and biochemical processes, which haven’t been well understood. This study aims to investigate the spatial distribution and vertical profiles of dissolved PAHs in the Beibu Gulf (BG) and adjacent waters of the South China Sea, along with hydrological, meteorological, and biochemical variables. Particularly relevant are the effects of atmospheric pressure, salinity, ammonium, chlorophyll-a, as well as riverine inputs (RI), sea currents, and upwelling. In surface seawater, the total concentrations of eight dissolved PAHs (∑8PAHs) were 7.76 ± 2.16 ng/L, with a distribution pattern of western Guangdong waters (WGWs) > BG > Qiongzhou Strait (QS). ∑8PAHs in the northern BG (9.10 ± 2.00 ng/L) was significantly higher than that in the southern BG (6.65 ± 1.54 ng/L) (p < 0.01), suggesting that local anthropogenic activities and unique environmental characteristics significantly influenced PAHs distribution. In water column, PAHs in BG displayed enrichment in surface and bottom but decreased in medium water, while those in WGWs and QS decreased with increasing depth. Source apportionment concluded that PAHs in QS and WGWs were primarily from petroleum sources, and PAHs in BG were mainly from coal combustion. RI, combined with circulation, coastal current, and intrusion of SCS water influenced the surface PAHs distribution in BG, with eddy impacts observed. Specifically, regarding the surface PAHs distribution, differences in atmospheric pressure may influence the air-sea exchange of PAHs, especially positively affecting 4-ring PAHs. Salinity factors further corroborated the contribution of RI to 3-ring PAHs, followed by the regulation of PAHs through biological pumps (ammonia and chlorophyll-a). Moreover, upwelling-induced biodegradation and resuspension affected the vertical distribution of PAHs. While most PAHs posed a negligible risk, coking-generated fluorene posed a moderate risk to ecosystems due to changes in the energy structure, warranting further investigation into its toxicological impacts.

Published in Ecotoxicology and Environmental Safety

ISSN: 0147-6513 (Print); 1090-2414 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Technology: Environmental technology. Sanitary engineering: Environmental pollution; Geography. Anthropology. Recreation: Environmental sciences
Website: https://www.journals.elsevier.com/ecotoxicology-and-environmental-safety

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