| 摘要: |
| 为了解南海北部陆架与陆坡区小型底栖动物的群落特征，以及影响群落特征的环境因素，2015年6月对南海北部海域（19.3°-21.4°N，112.4°-115.1°E）7个站位的小型底栖动物及环境因子进行了采样，并对陆架和陆坡区小型底栖动物群落的丰度、生物量、类群组成和群落结构进行比较。结果表明，在陆架站位，小型底栖动物由13个类群组成，平均丰度为（132±130）ind./10cm2，平均生物量为（169±79）μg dwt/10cm2；在陆坡站位由8个类群组成，平均丰度为（33±14）ind./10cm2，平均生物量为（56±35）μg dwt/10cm2。单因素方差分析结果表明，陆坡区小型底栖动物的总丰度和总生物量以及线虫和多毛类的丰度均显著低于陆架区，但优势类群的相对丰度组成没有显著不同，海洋线虫占总丰度的83%，其次为多毛类和桡足类，分别占7%和3%。环境因子的主成分分析（Principal Components Analysis，PCA）将陆架和陆坡站位沿第一主分量轴分开，小型底栖生物丰度和生物量与沉积物叶绿素a和脱镁叶绿酸含量以及底层水温呈最大正相关，与水深呈负相关；聚类（Cluster）和排序（non-metric Multidimensional Scaling，MDS），以相似性系数65%将7个站位划分为2组，与按照水深划分的陆架和陆坡组基本吻合；单因素相似性分析（one-way ANOSIM）显示陆架和陆坡区小型底栖动物群落结构差异显著；生物-环境分析（Biota-Environment，BIOENV）表明影响群落结构的最佳环境因子组合为叶绿素a和底层水温。综上可知，随水深增加的食物减少和底层水温的下降是限制南海北部研究海域小型底栖动物丰度和生物量及影响群落组成和结构的主要因素。 |
| 关键词: 小型底栖动物群落 丰度和生物量 组成和结构 陆架和陆坡 南海北部 |
| DOI：10.11693/hyhz20191100228 |
| 分类号:Q958.1 |
| 基金项目:国家自然科学基金资助项目，41376146号；国家海洋公益性行业专项，201505004号；中国海洋大学基本科研业务费，201262010号；2015年基金委南海北部共享航次。 |
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| COMPARISON IN MEIOFAUNAL COMMUNITIES BETWEEN SHELF AND SLOPE OF THE NORTHERN SOUTH CHINA SEA |
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ZHOU Hong, Saif MD UDDIN, HUANG Meng-Jiao, LIU Xiao-Shou, WANG Zheng-Mao, YIN Yong-Tong, JIANG Qian-Qian, Rebeca MONTERO-TABOADA, Karim MD ABDUL
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College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
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| Abstract: |
| To understand the characteristics of meiofaunal communities from the shelf and slope depths, and the most relevant environmental factors, meiofaunal and environmental samples were collected at seven stations in the northern South China Sea (19.3°-21.4°N, 112.4°-115.1°E) in June 2015, and compared in meiofaunal abundance, biomass, taxon composition and community structure between the shelf and slope stations. Results showed that at the shelf, the meiofauna consisted of 13 major groups in average abundance of (132±130)ind./10cm2 and biomass (169±79)μg dwt/10cm2, while at the slope, the meiofauna covered 8 major groups in significantly lower abundance of (33±14)ind./10cm2 and biomass of (56±35)μg dwt/10cm2 than those of the shelf. However, no significant difference was found in major taxon composition (Mann-Whitney U test), i.e., at both shelf and slope, nematode was the most dominant taxon(83% of the total abundance), followed by polychaete (7%) and copepod (3%). As PCA indicated, the separation of shelf and slope stations along PC1 and meiofaunal abundance and biomass were positively related with sedimentary chlorophyll a, phaeopigment, and bottom water temperature, while negatively related with water depth. At 65% similarity, Cluster and MDS classified the seven stations into two groups, which was largely consistent with the shelf and slope grouping. In addition, significantly different community structure was detected between the shelf and slope meiofaunal communities indicated by one-way ANOSIM according to the abundance matrix of major taxa. The best combination of environmental factors affecting meiofaunal community structure were chlorophyll a and bottom water temperature as revealed by BIOENV. Therefore, from the shelf to slope, as water depth increased, the food availability and bottom water temperature both decreased, and resulted in the different characteristics of meiofaunal communities between shelf and slope in the northern South China Sea. |
| Key words: meiofaunal community abundance and biomass composition and structure shelf and slope northern South China Sea |
