| 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 | |
| 马璐 ; 曹文清 ; 张文静 ; 林元烧 ; 郑连明 ; 杨位迪 ; 王宇杰 | |
| 2014-01-06 | |
| 关键词 | 微型浮游动物 摄食压力 浮游植物 稀释法 北部湾 microzooplankton grazing pressure phytoplankton dilution technique Beibu Gulf |
| 英文摘要 | 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 in nearshore than in offshore waters.Abundance did not differ significantly with chlorophyll a concentration in this study; however,there was a positive correlation between microzooplankton abundance and temperature.The phytoplankton growth rate( < 200 μm) ranged between-1.50 and 1.13 d-1,with the highest values being associated with nearshore waters.Meanwhile phytoplankton mortality due to microzooplankton grazing( 0.33—1.08 d-1) was highest at the same nearshore sites; however,growth rates were low at these sites.Consequently,microzooplankton consumed 28.1%—66.0% of chlorophyll a standing stocks and-8.1%—438.4% of the primary production per day.However,the grazing rate of microzooplankton on nanoplankton( 2— 20 μm) varied from 1.87 to 0.52 d-1,with an average of( 0.94±0.57) d-1.Given that the rates of grazing on phytoplankton of <200 μm were lower than those on nanoplankton,we conclude that microzooplankton prefer to graze on nanoplankton.There was a positive correlation between phytoplankton growth rate and grazing rate; in addition,significant differences between grazing rate and chlorophyll a were found.This suggests that microzooplankton grazing activity is the main factor regulating the community structure and restraining the growth of phytoplankton.During the investigation period, microzooplankton grazing effectively controlled the growth of phytoplankton,consuming 176.2% of primary production on average.When grazing rates are far greater than phytoplankton growth rates,energy is transferred from lower to higher trophic levels more effectively.In the surface waters of the northern Beibu Gulf,microzooplankton largely control the growth of phytoplankton by grazing offshore rather than in nearshore waters where primary production is high.The growth and grazing rates combined promote planktonic ecosystem stability in this area.These results indicate that grazing by microzooplankton is a key process controlling the growth of phytoplankton in this area.; 海湾公益项目(201005012) |
| 语种 | zh_CN |
| 内容类型 | 期刊论文 |
| 源URL | [http://dspace.xmu.edu.cn/handle/2288/104688]  |
| 专题 | 海洋环境－已发表论文 |
| 推荐引用方式 GB/T 7714 | 马璐,曹文清,张文静,等. 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[J],2014. |
| APA | 马璐.,曹文清.,张文静.,林元烧.,郑连明.,...&王宇杰.(2014).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.. |
| MLA | 马璐,et al."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".(2014). |
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