Estimation of primary production from the light absorption of phytoplankton and photosynthetically active radiation in the South China Sea

Frontiers in Marine Science

Marine Science

Kai Zeng¹  Jie Xu²  Jianzu Liao³  Lin Deng⁴  Wenxi Cao⁵  Wen Zhou⁵  Wendi Zheng⁵  Hongwuyi Zhao⁶  Yuanfang Zhang⁶ 

[1] Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China;Department of Ocean Science and Technology, University of Macau, Macao, Macao SAR, China;Faculty of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang, China;School of Marine Sciences, Sun Yat-sen University, Zhuhai, China;State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China;State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China;College of Oceanography, University of Chinese Academy of Sciences, Beijing, China;

关键词: primary production;    phytoplankton absorption coefficient;    photosynthetically active radiation;    phytoplankton pigments;    marine optics;   

DOI  :  10.3389/fmars.2023.1249802

 received in 2023-06-29, accepted in 2023-10-04,  发布年份 2023

来源: Frontiers

【 摘 要 】

A model was constructed to estimate Primary production (PP) and examine the effect of the dominant phytoplankton group on PP, using a dataset collected in 2019 in the South China Sea (SCS) based on phytoplankton absorption coefficient at 443nm [aph(443)] and photosynthetically active radiation (PAR). There was a significant log-log linear correlation between PP and the product of aph(443) and PAR (aph(443)×PAR), with an adjusted R2 of 0.64. The model was validated using K-fold cross-validation and an in situ dataset collected in 2018 in the SCS basin. The results showed that the model had good generalisability and was suitable across marine environments, including basin, coastal, and offshore areas. The model was more sensitive to changes in PAR than changes in aph(443). Phytoplankton in the diatom-dominant and haptophyte-dominant clusters were in the light-limited stage, and their PP values increased with increasing aph(443)×PAR. However, Prochlorococcus-dominant samples exhibited photoinhibition, and the PP values decreased with increasing aph(443)×PAR, likely due to their bio-optical characteristics. The model’s predictive power was related to the photo-physiological state of dominant phytoplankton, which performs well in light-limited conditions but not in cases of massive photoinhibition. This study provides insight into the development of phytoplankton-specific aph-based PP models.

【 授权许可】

Unknown   
Copyright © 2023 Zhao, Cao, Deng, Liao, Zeng, Zheng, Zhang, Xu and Zhou