北部湾鱼类群落格局及其与环境因子的关系

依据2016年北部湾防城港—钦州近岸海域的底拖网调查数据，分析了鱼类群落组成和资源的时空分布；同时结合温度、盐度、溶解氧、pH、深度5种水环境要素，探讨了该海域鱼类群落与环境因子间的关系。结果表明，该海域共捕获鱼类152种，隶属于15目55科96属，二长棘鲷 (Parargyrops edita)、鹿斑鲾 (Secutor ruconius)、多齿蛇鲻 (Saurida tumbil)、褐菖鲉 (Sebastiscus marmoratus) 等为优势种。资源量以春季最丰富，多样性指标春、夏季较高，冬季最低。聚类和NMDS分析得出，该海域可划分为4个鱼类组群，组内平均相似度介于18.27% (组群I) 至32.49% (组群II)。ANOSIM分析表明各组群间鱼类组成差异极显著 (R=0.703~0.982, P<0.01)，组群I与IV间存在最大相异性 (98.02%)。冗余分析 (RDA) 表明，底层温度、溶解氧、深度和底层盐度是影响北部湾防城港—钦州近岸海域鱼类分布的主要环境因子。

The role of submerged aquatic vegetation in influencing the abundance of nekton on contiguous tidal fresh-water marshes

We analyzed the fish assemblage composition and spatio-temporal distribution of fish stocks based on the bottom trawl survey data in Fangchenggang (Qinzhou coastal area of Beibu Gulf) in 2016. Combining with the information of temperature, salinity, dissolved oxygen, pH and depth, we investigated the relationship between fish community structure and environmental factors. A total of 152 fish species belonging to 15 orders, 55 families and 96 genera had been collected, and Parargyrops edita, Secutor Ruconius, Saurida tumbil and Sebastiscus marmoratus were the dominant species. The abundance of fish stocks was the highest in spring. The diversity index was higher in spring and summer, but lower in winter. Four distinct groups were defined by Cluster and non-metric multidimensional scaling (NMDS) analysis, and the average similarity of the groups ranged from 18.27% (Group I) to 32.49% (Group II). The analysis of similarity (ANOSIM) shows that the differences of fish composition among different groups were extremely significant (R=0.703−0.982, P<0.01), with the most sinificant difference of 98.02% between Group I and Group IV. The results of redundancy analysis (RDA) show that the bottom temperature, dissolved oxygen, depth and bottom salinity of bottom were the main environmental factors that affected fish distribution in Fangchenggang.