印度洋南赤道流区水体叶绿素a的分布及粒级结构  

The distribution of size-fractionated chlorophyll a in the Indian Ocean South Equatorial Current

作　　者：周亚东[1,2] 王春生[1,2] 王小谷[1,2] 刘镇盛[1,2] 卢勇[1,2] 刘晓辉[1,3] 

机构地区：[1]国家海洋局第二海洋研究所,杭州310012 [2]国家海洋局海洋生态系统与生物地球化学重点实验室,杭州310012 [3]卫星海洋环境动力学国家重点实验室,杭州310012

出　　处：《生态学报》2011年第16期4586-4598,共13页Acta Ecologica Sinica

基　　金：中国大洋矿产资源研究开发协会专项基金(DYXM-115-01-3-01;DYXM-115-01-3-02);国家海洋局第二海洋研究所基本科研业务费专项(JG1024)

摘　　要：根据2010年4—5月印度洋南赤道流区的综合环境调查资料,对印度洋南赤道流区叶绿素a浓度分布和浮游植物的粒级结构等进行了分析。结果表明,调查海区水体层化明显,表层水温较高,营养盐浓度较低。调查海区东部测站的数据显示该区域可能受到来自印度尼西亚贯穿流和南爪哇流的影响,有高温低盐的特点。叶绿素a浓度在该海区的分布具有以下特点:(1)表层叶绿素a浓度在整个调查海区虽然普遍较低(平均为(0.122±0.052)mg/m3),但具有明显的空间区域化特征:印度洋南赤道流区中部,叶绿素a浓度较低,站位间分布均匀;东部叶绿素a浓度相对较高,不同测站叶绿素a浓度差异明显。(2)整个调查区域叶绿素a浓度垂直分布具有明显的单峰结构,其最大值分布在60—80m水层,位于营养盐跃层内。(3)叶绿素a的粒级结构分析结果显示,pico级份的浮游植物对叶绿素a的贡献占主导地位,平均为75%,nano级份的贡献平均为20%,net级份对叶绿素a的贡献最小,平均仅有5%。对比调查和在其它海区的研究,表明印度洋南赤道流区属于典型的低纬度寡营养海区,低的营养盐浓度(特别是NO-3浓度)是该海区浮游植物生长的主要限制因素之一。An investigation of the distribution and size composition of chlorophyll a concentration（20 μm,2-20 μm,0.2-2 μm） was carried out from April to May 2010 in the South Equatorial Current（SEC） region（10°59′—14°6′S,80°00′—113°3′E） of the Indian Ocean.The survey was carried out during the inter-monsoon,which is characterized by weak vertical mixing and low upwelling.The objective of this study was to investigate the spatial distribution and size fraction of chlorophyll a concentration and to relate this to environmental factors.9 stations were surveyed and water samples were collected from 17 layers in 0—200 m water column of each station.A total of 9 profiles of size-fractionated chlorophyll a,nutrients（NO-3、PO3-4 and SiO2-3）,temperature and salinity were obtained.According to the location of the stations,the whole survey region was divided into two subregions,CIO（Central Indian Ocean） survey region and EIO（Eastern Indian Ocean） survey region.Results showed that the water column of the survey area is well stratified and the mixed layer was about 50 m throughout the region.The surface water was characterized by high temperature and low concentrations of nutrients.The eastern part of the EIO region was influenced by the intrusion of the Indonesian Throughflow and the South Java Current,which has high temperature and low salinity.Three characteristics of the chlorophyll a distribution were revealed：（1） Low chlorophyll a concentration of surface water was widespread in the region（0.122±0.052 mg/m3 on average）,but spatial pattern was also observed.The chlorophyll a concentration in the CIO survey region was uniformly low;however,relatively higher chlorophyll a concentration and higher inter-station variation was observed in the EIO survey region.（2） A subsurface chlorophyll a maximum layer occurred between 60 and 80 m,which coincided with the nutricline.（3） The 0.2—2 μm chlorophyll a always dominated and represented 75% of the total chlorophyll a on avera

关 键 词：叶绿素A 粒级结构 印度洋南赤道流区 寡营养 

分 类 号：Q948.8[生物学—植物学]