莱州湾渔业资源群落结构和多样性的年际变化

Interannual Variations in Community Structure and Species Diversity of Fishery Resources in the Laizhou Bay

中文关键词: 莱州湾  群落结构  多样性  年际变化

英文关键词: Laizhou Bay  Community structure  Species diversity  Interannual variations

中文摘要:

      根据2009–2013年每年8月在莱州湾水域进行的渔业底拖网调查数据，采用生态多样性指数和多元统计分析等方法,研究了该海域的渔业资源群落结构和多样性特征的年际变化。结果显示，调查共鉴定出100种资源种类，其中鱼类56种；渔业资源种类和资源量存在明显的年际变化，2013年渔业资源种类数为2012年种类数的84.4%，仅为2009年的60.3%，平均网获质量明显下降。鱼类优势种组成存在年际更替现象，主要由经济价值高、个体大的种类向经济价值低、个体小的种类演替。各生态多样性指数均呈现下降趋势，Margalef种类丰富度指数(R)变化范围为2.67-3.95，Shannon-Wiener多样性指数(H¢)变化范围为0.70-3.83，Pielou均匀度指数(J¢)变化范围为0.12-0.63。聚类分析(CLUSTER)和多维标度分析(MDS)分析表明，在相同的相似性水平上分组，组内平均相似性与组间相异性变大。单因子相似性分析(ANOSIM)表明，各年渔业群落结构均存在显著差异(P<0.05)。综上所述，莱州湾渔业资源逐年衰退，优势种更替明显，群落结构发生明显变化，多样性呈下降趋势。

英文摘要:

      In this study we evaluated the community structure and species diversity of the fish resources in the Laizhou Bay using ecological diversity indices and multivariate statistical analysis. Data were collected during the trawl surveys in August from 2009 to 2013. There were 100 species found in the survey, 56 of which were fish species. The relative biomass and species varied dramatically annually. The number of fishery species in 2013 dropped to 84.4% of the value in 2012, and only 60.3% of 2009. The average weight of catch per haul was also obviously decreased. The composition of dominant species displayed a pattern of interannual variation, and both the economic values and the sizes of the dominant species were continuously reduced over years. The ecological index showed a decreasing trend too. The Margalef species richness index (R), the Shannon-Wiener diversity index (H′), and the Pielou evenness index (J′) varied from 2.67 to 3.95, 0.70 to 3.83, and 0.12 to 0.63 respectively. Cluster analysis and multidimensional scaling (MDS) analysis showed that average similarity within the group and diversity between groups with interannual variation were increased at the same similarity level. ANOSIM analysis indicated that there were significant differences in the community structure from 2009 to 2013 (P<0.05). Our study suggested that the fishery resources had been declining and that there was a yearly substitution in the dominant species. The community structure of fishery resources has varied remarkably.