Effects of nutrient limitations on the sinking velocity of Thalassiosira weissflogii  

作　　者：Jie Zhu Qiang Hao Wei Zhang Yingying Ma Jiangning Zeng 

机构地区：[1]Ocean College,Zhejiang University,Zhoushan 316000,China [2]Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China [3]Key Laboratory of Marine Ecosystem Dynamics,Ministry of Natural Resources,Hangzhou 310012,China [4]Zhejiang Key Laboratory of Nearshore Engineering Environment and Ecological Security,Hangzhou 310012,China [5]Tianjin Key Lab of Aqua-Ecology and Aquaculture,College of Fisheries,Tianjin Agricultural University,Tianjin 300384,China

出　　处：《Acta Oceanologica Sinica》2024年第6期163-172,共10页海洋学报（英文版）

基　　金：The Key R&D Program of Zhejiang under contract No.2023C03120;the Science Foundation of Donghai Laboratory under contract No.DH-2022KF0215;the National Key Research and Development Program of China under contract No.2021YFC3101702;the National Programme on Global Change and Air-Sea Interaction (PhaseⅡ)—Hypoxia and Acidification Monitoring Warning Project in the Changjiang Estuary;Long-term Observation and Research Plan in the Changjiang Estuary and Adjacent East China Sea (LORCE) Project under contract No.SZ2001。

摘　　要：The sinking of diatoms is critic al to the formation of oceanic biological pumps and coastal hypoxic zones.However,little is known about the effects of different nutrient restrictions on diatom sinking.In this study,we measured the sinking velocity(SV) of Thalassiosira weissflogii using a new phytoplankton video observation instrument and analyzed major biochemical components under varying nutrient conditions.Our results showed that the SV of T.weissflogii under different nutrient limitation conditions varied substantially.The highest SV of(1.77±0.02) m/d was obtained under nitrate limitation,signific antly surpassing that under phosphate limitation at(0.98±0.13) m/d.As the nutrient limitation was released,the SV steadily decreased to(0.32±0.03) m/d and(0.15±0.05) m/d,respectively.Notably;under conditions with limited nitrate and phosphate concentrations,the SV values of T.weissflogii significantly positively correlated with the lipid content(P <0.001),with R^(2) values of 0.86 and 0.69,respectively.The change of the phytoplankton SV was primarily related to the intracellular compo sition,which is controlled by nutrient conditions but did not significantly correlate with transparent extracellular polymer and biosilica contents.The results of this study help to understand the regulation of the vertical sinking process of diatoms by nutrient restriction and provide new insights into phytoplankton dynamics and their relationship with the marine nutrient structure.

关 键 词：nutrient limitation Thalassiosira weissflogii sinking velocity biochemical component lipid content 

分 类 号：Q948.8[生物学—植物学]