长江口及邻近海域秋冬季小型底栖动物类群组成与分布  

Assemblage composition and distribution of meiobenthos in the Yangtze Estuary and its adjacent waters in autumn-winter season

作　　者：于婷婷[1,2] 徐奎栋[1] 

机构地区：[1]中国科学院海洋研究所,青岛266071 [2]中国科学院大学,北京100049

出　　处：《生态学报》2013年第15期4556-4566,共11页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划(973)(2011CB403604);中国科学院知识创新工程重要方向(KSCX2-EW-Z-5)资助

摘　　要：对2009年11—12月采自长江口及邻近的东海海域19个站位的小型底栖动物类群组成、丰度、生物量和空间分布及其与沉积环境的关系进行了研究。结果表明,该海域秋冬季小型底栖动物的平均丰度和生物量分别为(1081±700)个/10 cm2和(600±374)μg干重/10 cm2,均呈现由北往南、由近岸向外海递减的趋势,且在长江口冲淡水向东海的扩展区域内,小型底栖动物的丰度明显较东海外围海域高。该数量与同一海域春季的研究结果相近,但明显低于夏季。在分选出的12个主要类群中,海洋线虫在丰度上占绝对优势(94.4%),其次是涡虫类(2.3%)和桡足类(2.0%)。线虫也是生物量上的最优势类群(占68.1%),其次是涡虫类(14.8%)、桡足类(6.8%)和多毛类(5.8%)。在垂直分布上,占总量70.8%的小型底栖动物和69.9%的线虫分布于0—2 cm表层,均高于54%—65%的历史资料。Spearman相关分析表明,小型底栖动物丰度与叶绿素a含量呈显著正相关,与水深、底层水温和底层盐度呈显著负相关。BIOENV分析显示与小型底栖动物类群组成和丰度相关性最高的环境因子组合为水深和脱镁叶绿素a含量。海洋线虫与桡足类数量之比(N/C)可大致反映本海域沉积环境的质量状况,但沉积物类型等因素的影响可造成环境评价的偏差。通过对639条线虫生物体积的测算,获得两个站位的线虫平均个体干重分别为0.104μg/个和0.365μg/个。研究表明,我国当前普遍采用的0.4μg/个这一系数估计的线虫生物量将不同程度地高估其实际生物量。We investigated the assemblage composition, abundance, biomass and spatial distribution of meiobenthos in relation to benthic environmental variables at 19 stations in the Yangtze （Changjiang） Estuary and its adjacent waters in the East China Sea from November to December 2009. The average abundance of meiobenthos was （1081±700） ind/10 cm2 and the biomass was （600±374） μg dwt/10 cm2. There was an overall trend in both the abundance and biomass decreasing from the north to the south sea area and from the inshore to the offshore area. Moreover, the abundance was markedly higher in the dilution zone of the Yangtze River than that in the surrounding offshore area. The standing crops of meiobenthos were similar to those obtained from the same area in spring （from April to May 2007）, but distinctly lower than those in summer （June 2003）. Among the 12 meiobenthos assemblages identified, nematodes were most abundant, accounting for 94.4% of the total abundance, followed by turbellarians （2.3%） and copepods （2.0%）. In terms of biomass, nematodes accounted for 68.1%, and followed by turbellarians （14.8%）, copepods （6.8%） and polychaetes （5.8%）. There were about 70.8% of the total meiobenthos individuals and 69.9% of the nematodes distributed in the surface 0-2 cm sediment layer. These proportions were higher than those recorded in this area （from 54% to 65%）. Spearman correlation analysis showed that meiobenthos abundance was positively correlated with sediment chlorophyll-a concentration, and negatively correlated with water depth, bottom water temperature and bottom water salinity. BIOENV analysis suggested that the combination of environmental variables that best correlated with meiobenthos communities consisted of water depth and sediment phaeophytin-a concentration. Our data indicated that the abundance ratio of nematodes to copepods （N/C） generally coincided with the benthic environmental condition in the study area. However, differences in sediment types might discr

关 键 词：长江口 东海 小型底栖动物 线虫 丰度 生物量 

分 类 号：Q958.8[生物学—动物学]