Phytoplankton Communities Miniaturization Driven by Extreme Weather in Subtropical Estuary under Climate Changes

• Published in: Water research (Oxford) Vol. 245; p. 120588
• Main Authors: Ding, Xiang, Liu, Jiaxing, Liu, Weiwei, Dai, Sheng, Ke, Zhixin, Guo, Jia, Lai, Yanjiao, Tan, Yehui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.10.2023
• Subjects: autumn; Bacillariophyceae; Chlorophyta; climate; climate change; cold; Cold waves; Cryptista; estuaries; Extreme weather; genus; Heavy precipitation; Miozoa; Ochrophyta; phytoplankton; Phytoplankton community; river flow; rivers; spring; Subtropical estuarine ecosystems; summer; temperature; water; weather; winter; SRP; ASVs; Cold waves; Extreme weather; NOx; Phytoplankton community; Subtropical estuarine ecosystems; T-S; Heavy precipitation; RDA
• DOI: 10.1016/j.watres.2023.120588
• ISSN: 0043-1354; 1879-2448

•Extreme weather may miniaturize the phytoplankton community in subtropical estuaries•Low light and high nutrient conditions favored the growth of Ostreococcus tauri•2020/2021 super-cold wave provided a competitive advantage for the survival of Teleaulax Estuarine ecosystems are subject to extreme weather and climatic events, particularly global climate change. To characterize the effects of extreme weather, such as heavy precipitation and cold waves, on phytoplankton communities, four seasonal cruises were conducted in the subtropical Pearl River Estuary. Among the main phytoplankton taxa, small (pico- and nano-sized) phytoplankton accounted for approximately 50% and 70% in the upstream estuary. In spring, summer, and autumn, small-sized phytoplankton communities were dominated by Chlorophyta (20–45%), Ochrophyta (Bacillariophyceae; 25–40%), and Dinoflagellata (20–25%), associated with high phytoplankton network stability and river discharge. In winter, small phytoplankton communities were dominated by Cryptophyta (50%), Dinoflagellata (25%), and Ochrophyta (Bacillariophyceae; 10%), which were associated with low network stability and temperature. Low light and high nutrient conditions induced by large river discharge favored the growth of the smallest known brackish Chlorophyta, such as Ostreococcus tauri. Low temperatures provided a competitive advantage for the survival of the small-sized cryptophyte genus Teleaulax, especially in the upstream estuary during the 2020/2021 extreme cold wave period. Our findings highlight the impact of extreme weather induced by climatic events on the miniaturization of phytoplankton communities in subtropical estuaries by altering temperature, light availability, and nutrient dynamics. [Display omitted]