山东半岛南部近岸海域夏季游泳动物的组成特征

根据2008年8月在山东半岛南部近岸海域进行的底拖网调查资料,对该海域游泳动物组成特征进行了初步研究。结果表明,在该海域共捕获游泳动物54种,平均相对资源量为129.9 kg/h。以生物量为单位计算群落多样性,Shannon-Wiener种类多样性指数H′平均为1.43,Margalrf种类丰富度指数D平均为1.18,Pielou种类均匀度指数J′平均为0.63。优势种为鳀和戴氏赤虾,重要种为方氏锦鳚、日本蟳、小黄鱼、矛尾虾虎鱼、口虾蛄和枪乌贼。通过聚类分析表明该海域游泳动物群落结构存在一定程度的空间异质性,主要包括3组,引起组间平均相异性贡献的分歧种主要包括戴氏赤虾、方氏锦鳚、矛尾虾虎鱼、日本蟳、双斑蟳、枪乌贼和口虾蛄等。山东半岛南部近岸海域渔业资源呈现出小型化和低质化的趋势。

On nekton composition in southern coastal waters off Shandong Peninsula in summer

Based on the bottom trawl surveys in the southern coastal waters off Shandong Peninsula in August 2008,the characteristics of nekton composition was preliminarily analyzed.Results indicated that there were 54 species collected from the bottom trawl surveys.The mean relative catches was 129.9 kg/h.The species richness D,Shannon diversity index H′ and evenness index J′ were 1.18,1.43 and 0.63 for nekton communiry,respectively.The dominant species were Engraulis japonicas and Metapenaeopsis dalei.The important species were Pholis fangi,Charybdis japonica,Larimichthys polyactis,Chaeturichthys stigmatias,Oratosquilla oratoria and Loligo sp..The species composition structure included 3 groups on the level of 35%.Similarity of percentage analysis was used to find out which species were most responsible for the discrimination between groups.In these surveys,those species were Metapenaeopsis dalei,Pholis fangi,Chaeturichthys stigmatias,Charybdis japonica,Charybdis bimaculata,Loligo sp.and Oratosquilla oratoria,which contributed most to the average dissimilarity and were discriminators for all between-groups.The fishery resources were characterized by small-scale fishes of low values.