长江口及毗邻海域大型底栖动物的次级生产力(英文)

Secondary Production of Macrobenthos in the Yangtze River Estuary ant Its Adjacent Waters

根据2005年与2006年在长江口及其毗邻海域,采用改进型0.1m2的Gray-O’Hara箱式采泥器,对85个站位进行的大型底栖动物定量调查资料,利用Brey’s(1990)的经验公式对底栖生物的次级生产力、P/B值及其空间分布状况进行统计和分析.结果表明,该海域共发现大型底栖动物330种,平均栖息密度为(146.4±22.3)indm-2,平均生物量以无灰干重计,为(2.31±0.41)g(ash-free dryweight,AFDW)gm-2.调查海域大型底栖动物的平均次级生产力以无灰干重计,为(2.48±0.38)g(AFDW)m-2a-1.在空间分布上,底栖生物的次级生产力自西向东,或自近岸向外海逐渐升高,并在调查区中部形成垂直于河口并与海岸大致平行且呈带状分布的高生产力中心,之后,次级生产力随水深增加呈现下降趋势.根据地理位置差异,整个研究区域被分为5个亚区,次级生产力在各亚区之间呈现显著差异.其中位于最西侧的河口亚区(HK)与杭州湾亚区(HW),由于受到强大的淡水注入以及污水排放影响,成为整个研究区的低生产力中心.通过与其它研究相比较可以得出,对于理化条件复杂多变的河口区,大型底栖动物通常具有较低的次级生产力.此外,研究区大型底栖动物的平均P/B比为(1.48±0.06)a-1,显示该区域大多数物种通常个体较小且更新率较高.

A annual survey （2005～2006） was carried out at the Estuary of the Yangtze River and its adjacent waters in China to investigate the current status of secondary production of macrobenthos.A 0.1 m 2 improved Gray-O＇Hara box-corer was used to collect the material from 85 sampling stations.330 species were found in the study area,with mean abundance of （146.4 ± 22.3） ind m-2,mean biomass （ash-free dry weight,AFDW） （2.31 ± 0.41） g m-2 and mean secondary production （2.48 ± 0.38） g （AFDW） m-2 a-1.Generally,the value of the secondary production of the macrobenhos has a obvious spatial distribution tendency,gradually increased from the west part （nearshore） to the east （offshore）,up to a turning line of central part of the study area facing to the river mouth and nearly parallel to the coast line,where forming a high value belt,and then decreasing with the increasing of water depth.Based on the difference of geography,five sub-areas could be defined in the study area with significant difference in the secondary production.Among them,two sub-areas （HK and HW,located in the west part of the study area） have low production due to the influence of strong freshwater inflow and concomitant sewage.Comparing to the previous study on other sea areas of China,the Yangtze River Estuary has a relatively low value of secondary production which mostly results from the complicated and diverse environments there.The mean P/B ratio of the macrobenthos is （1.48 ± 0.06） a-1,indicating that the community there is usually predominant with small individuals and a high recruitment rate.