北冰洋中心区表层海水营养盐及浮游植物群落对快速融冰的响应  

RESPONSE OF NUTRIENTS AND THE SURFACE PHYTOPLANKTON COMMUNITY TO ICE MELTING IN THE CENTRAL ARCTIC OCEAN

作　　者：庄燕培[1] 金海燕[1] 陈建芳[1] 王斌[1] 李宏亮[1] 陈法锦[1] 卢勇[1] 徐杰[2] 

机构地区：[1]国家海洋局第二海洋研究所,国家海洋局海洋生态系统和生物地球化学重点实验室,浙江杭州310012 [2]环境学部,香港科技大学,中国香港九龙清水湾

出　　处：《极地研究》2012年第2期151-158,共8页Chinese Journal of Polar Research

基　　金：国家自然科学基金(41076135,41003036);国家海洋局第二海洋研究所基本科研业务费专项(JG200820);海洋公益性行业科研专项(200805095)资助

摘　　要：依托2010年夏季中国第四次北极科学考察,通过对高纬度极地冰下水和冰芯的营养盐的连续观测及表层水颗粒物的藻类色素分析,获取了夏季快速融冰下冰水界面营养盐和光合色素的分布信息。结果表明调查期间表层水磷酸盐和硅酸盐相对于无机氮更丰富(依据Redfield比值),表现为显著的氮限制。而冰芯无机氮浓度相对更高,融冰释放对水体无机氮有一定的补充。色素分析显示岩藻黄素(Fuco)和叶绿素a(Chl a)是水体颗粒物的主要光合色素。在8月15日—8月18日期间,叶绿素c(Chl c)、硅藻黄素(Diato)、硅甲藻黄素(Diadino)和岩藻黄素(Fuco)分别达到6、22、73和922μg.m-3,体现了硅藻在群落中的优势地位。岩藻黄素(Fuco)的浓度在融冰快速期间有巨大的提升,主要来源于冰芯底部释放的衰老的冰生硅藻和浮游硅藻的生长。此外,青绿黄素(Prasino)和叶黄素(Lut)与岩藻黄素(Fuco)分布模式有明显的差异,暗示青绿藻和绿藻与硅藻对海冰融化的不同响应。During the fourth Chinese National Arctic Research Expedition cruise in summer 2010, a time-series observa- tion was carried out to examine the response of nutrients and phytoplankton community in the ice-water interface to the ice melting in the central Arctic Ocean. Phosphate and silicate in the ice-water interface were rich relative to dissolved inorganic nitrogen （DIN） , based on the Redfield ratio （16N： 1P： 16Si） , suggesting that [）IN was the po- tential limiting nutrient. DIN concentrations in the sea ice were about 3---4 times that in the surface seawater, indi- cating that melting ice delivered DIN to the surface water. Pigment analysis showed that fucoxanthin and chlorophyll a contribute to carotenoids and chlorophylls in particles. The mean concentrations of chlorophyll c, diatoxanthin, diadinoxanthin and fucoxanthin from 15 August to 18 August were 6 p^g ~ m-3, 22 p,g ~ m-3 , 73 p,g ~ m-3 and 922 -3 ixg ~ m , respectively, suggesting that diatoms dominated in the phytoplankton community composition. Further- more, a notable enhancement in fucoxanthin and chlorophyll a during a large-scale ice melting was likely attributed to senescent diatoms released from the bottom sea-ice as well as phytoplankton diatoms growth in the water column due to the input of nutrients （i. e. DIN） and reducing light limitation from melting ice. Temporal distribution pat- terns of prasinoxanthin and lutein differed from fucoxanthin, indicating that the response of green algae and diatoms to ice melting were different.

关 键 词：海冰融化 光合色素 营养盐限制 北极 

分 类 号：Q948.8[生物学—植物学]