Search
E-mail
RSS

Online submission Editor-in-chief Peer review Staff Login

Journal of Tropical Oceanography

Previous Articles    

Long-term variation of dissolved organic carbon and its influencing factors in Sanya Bay

ZHOU Weihua1, 2, 3, YAO Yukun1, 2, 3, 4, LUO Yong1, 2, 3, LI Tao1, 2, 3, LONG Aimin1, 4, HUANG Hui1, 2, 3   

  1. 1. Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;

    2. Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572000, China;

    3. Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya 572000, China;

    4. University of Chinese Academy of Sciences, Beijing 100049, China

  • Received:2025-06-09 Revised:2025-08-13 Accepted:2025-08-18
  • Supported by:
    Natural Science Foundation of Hainan Province (425QN506)

PDF (PC)

Like

Abstract: To explore the spatio-temporal changes and trends and environmental impact factors of dissolved organic carbon (DOC) in Sanya Bay, the water physicochemical parameters collected from 2008 to 2023 in Sanya Bay were used as the input data of the stepwise regression analysis (SR) and random forest algorithm (RF). The results showed that the DOC concentration increased significantly from 2008 to 2018 and then showed a downward trend. The high-value zones of DOC were found on the coastal areas of Sanya Bay. The mean value of DOC concentration was (2.00±1.34) mg·L-1, which was maintained at a lower level compared to other semi-enclosed bays. The results of SR and RF showed that: DOC had nonlinear relationships with temperature, total alkalinity and silicate; DOC had significant negative correlations with total phosphorus, dissolved oxygen and phosphate. These results demonstrated that temperature, total alkalinity, total phosphorus, silicate, dissolved oxygen and phosphate were the main factors affecting DOC in Sanya Bay. This study clarified the changing trends of DOC and its main influencing factors in Sanya Bay over the past sixteen years, laying a foundation for further research in the carbon cycle in tropical bays.

Key words: Dissolved organic carbon, spatio-temporal distribution, environmental factors, Sanya Bay