Effects of sea ice melt water input on phytoplankton biomass and community structure in the eastern Amundsen Sea  

作　　者：FENG Yubin LI Dong ZHAO Jun PAN Jianming ZHANG Haisheng HAN Zhengbing ZHU Qiuhong 

机构地区：[1]Second Institute of Oceanography,Ministry of Natural Resources(MNR),Hangzhou 310000,China

出　　处：《Advances in Polar Science》2022年第1期14-27,共14页极地科学进展（英文版）

基　　金：financially supported by National Polar Special Program “Impact and Response of Antarctic Seas to Climate Change” (Grant nos. IRASCC 02-02, 01-01-02);supported by the National Natural Science Foundation of China (Grant nos. 41976228, 41976227, 41506223);the Scientific Research Fund of the Second Institute of Oceanography, MNR (Grant nos. JG1805, JG2011, JG2013)。

摘　　要：Sea ice melt water and circumpolar deep water(CDW)intrusion have important impacts on the ecosystem of the Amundsen Sea.In this study,samples of nutrients and phytoplankton pigments from nine stations in the eastern Amundsen Sea were collected during the austral summer.Based on in-situ hydrological observations,sea ice density data from satellite remote sensing,and chemical taxonomy calculations,the relationships between environmental factors and phytoplankton biomass and community structure were studied.The results showed that with increasing latitude,the contribution of sea ice melt water(MW%)and the stability of the water body increased,and the depth of the mixed layer(MLD)decreased.The integrated concentration of chlorophyll a(Chl-a)ranged from 21.4 mg·m^(−2) to 148.4 mg·m^(−2)(the average value was 35.7±53.4 mg·m^(−2)).Diatoms(diatoms-A[Fragilariopsis spp.,Chaetoceros spp.,and Proboscia spp.]and diatoms-B[Pseudonitzschia spp.])and Phaeocystis antarctica were the two most widely distributed phytoplankton groups and contributed 32%±16%and 28%±11%,respectively,of the total biomass.The contributions of Dinoflagellates,Chlorophytes,Cryptophytes,the high-iron group of P.antarctica,and Diatom group A were approximately 17%±8%,15%±13%,9%±6%,5%±9%,and 3%±7%,respectively.The area with the highest phytoplankton biomass was located near the ice-edge region,with a short time lag(T_(lag))between sampling and complete sea ice melt and a high MW%,while the area with the second-highest Chl-a concentration was located in the area affected by the upwelling of CDW,with thorough water mixing.Vertically,in the area with a short T_(lag) and a shallow MLD,the phytoplankton biomass and proportion of diatoms decreased rapidly with increasing water depth.In contrast,in the region with a long T_(lag) and limited CDW upwelling,the phytoplankton community was dominated by a relatively constant and high proportion of micro phytoplankton,and the phytoplankton biomass was low and relatively stable vertically.Generally,the p

关 键 词：Amundsen Sea sea ice melt water mixed layer depth PHYTOPLANKTON PIGMENTS BIOMASS 

分 类 号：P73[天文地球—海洋科学] Q948.8[生物学—植物学]