冰藻对南大洋大西洋扇区南极磷虾越冬期间碳源的贡献  

CONTRIBUTION OF ICE ALGAE TO CARBON SOURCES OF ANTARCTIC KRILL FROM THE SOUTHWEST ATLANTIC SECTOR OF THE SOUTHERN OCEAN DURING WINTER

作　　者：陈晓丽 张吉昌[5,6] 王新良[5,6] 韩正兵 彭全材[1,2,4] 王延清 杨光 CHEN Xiao-Li;ZHANG Ji-Chang;WANG Xin-Liang;HAN Zheng-Bing;PENG Quan-Cai;WANG Yan-Qing;YANG Guang(Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Laoshan Laboratory,Qingdao 266237,China;University of Chinese Academy of Sciences,Beijing 100049,China;Center for Ocean Mega Science,Chinese Academy of Sciences,Qingdao 266071,China;Key Laboratory of Sustainable Development of Polar Fishery,Ministry of Agriculture and Rural Affairs,Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences,Qingdao 266071,China;Joint Laboratory for Open Sea Fishery Engineering,Laoshan Laboratory,Qingdao 266237,China;Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;Engineering Technology Department,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China)

机构地区：[1]中国科学院海洋研究所海洋生态与环境科学重点实验室,山东青岛266071 [2]崂山实验室,山东青岛266237 [3]中国科学院大学,北京100049 [4]中国科学院海洋大科学中心,山东青岛266071 [5]中国水产科学研究院黄海水产研究所农业农村部极地渔业可持续利用重点实验室,山东青岛266071 [6]崂山实验室深蓝渔业工程联合实验室,山东青岛266237 [7]自然资源部第二海洋研究所,浙江杭州310012 [8]中国科学院海洋研究所工程技术部,山东青岛266071

出　　处：《海洋与湖沼》2023年第4期1101-1112,共12页Oceanologia Et Limnologia Sinica

基　　金：青岛海洋科技中心专项经费资助,2022QNLM030002-1号;中国科学院海洋大科学中心重点部署项目,COMS2020Q08号;南极重点海域对气候变化的响应和影响,IRASCC 01-02-01D号;泰山学者工程项目。

摘　　要：南极磷虾是南大洋生态系统的关键物种,种群聚集在南大洋的大西洋扇区。海冰在南极磷虾生活史中起着重要作用,海冰及其冰下环境为磷虾越冬提供了避难场所,但海冰是否为磷虾越冬提供了重要的饵料存在一定的争议,对此问题的解决需要量化源于海冰的冰藻对南极磷虾越冬期间饵料及碳源的贡献。基于2020年冬季(3~8月)于南大洋大西洋扇区48.1亚区(布兰斯菲尔德海峡周边区域)和48.3亚区(南乔治亚岛周边海域)采集的磷虾样品,通过两种高支链类异戊二烯化合物(IPSO_(25)和HBIⅢ)分别作为源于海冰的冰藻和源于水体浮游植物的生物标志物,对两个区域冬季磷虾对冰藻和浮游植物的依赖进行研究。结果显示,处于较高纬度、海冰密集度较高的48.1亚区的南极磷虾体内含有更高的IPSO_(25),而处于开阔水域48.3亚区的磷虾体内有更高比例的HBIⅢ,另外48.3亚区磷虾的δ^(13)C和δ^(15)N稳定同位素显著高于48.1亚区的磷虾。48.1亚区南极磷虾越冬期间对浮游植物和冰藻的依赖与体长相关,其中体长相对较短的早期成体呈现更高的依赖性,同时该区域磷虾对冰藻的摄食提高了其营养级地位。48.3区南极磷虾越冬期间两种类异戊二烯含量与δ^(15)N稳定同位素数值呈负相关关系,表明该区域南极磷虾在初级生产匮乏时会摄食动物性饵料。若未来南大洋大西洋扇区海冰持续减少,这将对整个磷虾种群、磷虾渔业的可持续发展和区域生态系统的稳定性产生威胁。Antarctic krill(Euphausia superba),with majority of total stock concentrated in the Atlantic sector,is the keystone species of the Southern Ocean ecosystem.Sea ice plays great roles in the lifecycle of Antarctic krill.However,if ice algae provides important food source for krill during winter is under debate.Therefore,we need to quantify the contribution of sea ice derived carbon to Antarctic krill during winter.Based on krill samples collected in the regions near the Bransfield Strait area(CCAMLR zone 48.1,March-May 2020)and South Georgia(CCAMLR zone 48.3,June-August 2020),we analyzed the contribution of ice algae and phytoplankton to the carbon sources of krill using two highly branched isoprenoid biomarkers(IPSO_(25)and HBIⅢ).Results show that krill from zone 48.1 with relatively higher latitude and ice concentration contained high amounts of IPSO_(25),while krill from zone 48.3 showed higher values of HBIⅢand stable isotopes(δ^(13)C andδ^(15)N).The dependence of krill to phytoplankton and ice algae in zone 48.1 was size related,with smaller krill showing higher dependency on the primary production,while feeding on ice algae resulted in raised trophic level of krill.The negative correlations between the concentrations of isoprenoid biomarkers andδ^(15)N indicates that krill from the zone 48.3 mainly predated on animal-sourced foods during winter.Continuous decline of sea ice in the southwest Atlantic sector of the Southern Ocean in future would threaten the whole krill population,the sustainable development of krill fishery,and the stability of regional ecosystems.

关 键 词：南极磷虾 冰藻 浮游植物 越冬 南大洋 高支链类异戊二烯 

分 类 号：Q958[生物学—动物学]