Journal of Tropical Oceanography

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Distribution characteristics and pollution assessment of biogenic elements in sediments of Maowei Sea*

WANG Zeyu1, LU Dongliang1, 2, 3*,ZHOU Jiaodi1, 2*, JIN Zhuling1, LU Jinfeng1, LI Chenyang1   

  1. 1. College of Marine Sciences, Beibu Gulf University, Qinzhou, 535011, China;

    2. Guangxi Key Laboratory of Marine Environmental Disaster Processes and Ecological Protection Technology, Beibu Gulf University, Qinzhou 535011, China;

    3. Pinglu Canal and Beibu Gulf Coastal Ecosystem Observation and Research Station of Guangxi, Beibu Gulf University, Qinzhou 535011, China



  • Received:2025-10-16 Revised:2025-12-15 Accepted:2025-12-19
  • Supported by:

    Guangxi Natural Science Foundation(2021GXNSFDA075004, 2025GXNSFDA02850005); National Natural Science Foundation of China(41966002, 42166002); Guangxi Key Laboratory of Marine Environmental Change and Disaster inBeibu Gulf, Independent Project (2023ZZ201) and Open Topic (2020KF02); Experimental Research on Beibu Gulf Scientific Expedition 2023 under the National Natural Science Foundation of China-Shared Voyage Program(Voyage No: NORC2024-11)Proiect(42349911); Guangxi Beibu Gulf Marine Ecological Environment Field Observation and Research Station(23026271)

    Corresponding author: LU Dongliang. email: ldl@bbgu.edu.cn; ZHOU Jiaodi. emai: Zhoujodie@bbgu.edu.cn

Abstract: This study is based on the investigation and analysis of surface sediment samples collected from 16 sampling stations in Maowei Sea in July 2024 (wet season) and December 2024 (dry season). The pollution status of the sediments was evaluated using the comprehensive pollution index method and the organic pollution index method. The results show that: in the wet season, the mass fraction ranges of total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and biogenic silica (BSi) are 0.296%~0.953%, 0.010%~0.112%, 0.027%~0.155%, and 0.291%~0.520%, respectively; in the dry season, their mass fraction ranges are 0.038%~1.487%, 0.004%~0.127%, 0.016%~0.113%, and 0.089%~0.982%, respectively.In the dry season, the contents of TOC, TN, and BSi were higher than those in the wet season, while TP showed no significant seasonal difference. Generally, the contents of biogenic elements exhibited a decreasing trend from the estuaries to the outer bay. The TOC/TN ratio indicated that the organic matter in the wet season originated from mixed terrestrial and marine inputs, whereas it was dominated by terrestrial inputs in the dry season. The distribution of biogenic elements was significantly affected by sediment grain size and moisture content (P < 0.05). In the dry season, chlorophyll a(Chl-a) was significantly correlated with TP (P < 0.01). Pollution assessment revealed that overall, TN was at the slight pollution level and TP at the moderate pollution level, with these polluted areas mainly distributed in the estuarine regions of the Maoling River and Qin River; no organic pollution was detected. The results of this study provide a scientific basis for the monitoring and risk management of the sediment ecological environment in Maowei Sea during the construction of the Pinglu Canal Project.

Key words: Surface sediments, Biogenic elements, Pollution assessment, Spatiotemporal distribution, Maowei Sea