北部湾北部海域夏季微型浮游动物对浮游植物的摄食压力  

An ecological study on zooplankton in the northern Beibu Gulf V: the effects of microzooplankton grazing on phytoplankton in summer

作　　者：马璐[1,2] 曹文清[1,2] 张文静[1,2] 林元烧[1,2] 郑连明[1,2] 杨位迪[1,2] 王宇杰[1,2] 

机构地区：[1]厦门大学海洋与地球学院 [2]厦门大学海洋生物多样性与全球变化实验室,厦门361005

出　　处：《生态学报》2014年第3期546-554,共9页Acta Ecologica Sinica

基　　金：海湾公益项目(201005012)

摘　　要：2011年8月份于北部湾北部海域5个观测站位获得的分层水样,分析了表层叶绿素a含量和表层微型浮游动物丰度以及类群组成;同时于现场采用稀释培养法研究了该海域浮游植物生长率(μ)和微型浮游动物的摄食率(g)。分析和测定结果表明:调查海区的微型浮游动物丰度400—1167个/L,类群组成以无壳纤毛虫为主;浮游植物的生长率为-1.50—1.13 d-1,微型浮游动物摄食率为0.33—1.08 d-1;推算微型浮游动物对浮游植物现存量以及初级生产力的摄食压力分别为28.1%—66.0%和-7.4%—438.4%。相对于中国其他海区,8月份北部湾北部海域微型浮游动物摄食速率处于中等水平。调查期间,广西沿海高生产力海区,浮游植物生长率大于微型浮游动物动物的摄食率,浮游植物生物量处于积累期;涠洲岛以南海域,浮游植物生产力较低,微型浮游动物摄食作用是控制浮游植物生长的重要因素。In August 2011, we quantified the impact of microzooplankton grazing on phytoplankton production in the surface waters of the northern Beibu Gulf, Vietnam. Shipboard dilution incubation experiments were carried out at five stations to calculate phytoplankton specific growth rates and the specific rates of grazing losses to microzooplankton. Dilution experiments using chlorophyll a （Chl a） as a tracer were used to estimate daily rates in two size fractions; image-analyzed microscopy provided quantitative estimates of microzooplankton standing stock （including ciliate and vertebrate larvae ）. PFW （particle-free water） was used to dilute seawater to five target dilutions of 0%, 20%, 40%, 60%, and 80%. Microzooplankton grazing and phytoplankton growth rates were estimated by the linear regression of AGR （ apparent growth rate） versus dilution factor. We estimated the grazing impact of microzooplankton on phytoplankton by calculating the percentage of phytoplankton standing stock and potential primary production ingested. Average total chlorophyll a concentration was （ 0.67 ±0.58 ） μg/L. Small-celled phytoplankton dominated this particular community. A notable characteristic of the phytoplankton community structure was that nano- and picoplankton made up a significant portion. Aloricate ciliates dominated the microzooplankton samples, in particular Strombidium, which accounted for 27.2% of total aloricate ciliate abundance. In addition, loricate ciliates and copepod nauplii were recorded. Microzooplankton densityvaried from 400 to 1167 ind/L. The horizontal distribution of microzooplankton was greater waters. Abundance did not differ significantly with chlorophyll a concentration in this study; correlation between microzooplankton abundance and temperature. The phytoplankton in nearshore than in however, there was a offshore positive growth rate （ 〈 200 μm ） ranged between -1.50 and 1.13 d-l, with the highest values being associated with nearshore waters. Meanwhile phytoplankton mortality

关 键 词：微型浮游动物 摄食压力 浮游植物 稀释法 北部湾 

分 类 号：Q958.8[生物学—动物学]