海洲湾北部海域春季渔业资源的群落结构特征

根据2012年5月(春季)在海洲湾北部海域进行的渔业资源底拖网调查资料,分析了该海域渔业资源群落结构特征。结果表明,该海域共捕获渔业资源种类51种(鱼类33种、甲壳类14种、头足类4种),平均渔获量为24.59 kg/h。优势种类主要为尖海龙(Syngnathus acus)、方氏云鳚(Pholis fangi)和戴氏赤虾(Metapenaeopsis dalei)。渔业生物群落的种类丰度指数D在1.400–3.255之间,平均为2.471;多样性指数H′在0.492–2.309之间,平均为1.857;均匀度指数J′在0.182–0.713之间,平均为0.596。本次调查出现鱼类种数比20世纪80年代记载的鱼类150种大幅降低;甲壳类、头足类比相关调查显示甲壳类19种、头足类6种的结果也有所降低。主要经济鱼类个体质量和数量减少,小型低价值鱼类及戴氏赤虾逐渐成为优势种,且未发现经济鱼类带鱼(Trichiurus lepturus),这可能与过度捕捞或其他人为活动扰动有关。

Fishery Resources in Northern Haizhou Bay in Spring

In order to track the fishery resources in Haizhou Bay, we conducted preliminary studies on the community structure of fishery resources in the northern area of Haizhou Bay. The data were collected in bottom trawl surveys in May 2012 （spring）. In the survey totally 51 species were collected including 33 species of fish, 14 species of crustaceans and 4 species of cephalopods. The range of the biomass distributions of fishery resources was 13.55？35.90 kg/h, with an average of 24.59 kg/h. The range of the number distributions of fishery resources was 1858？14844 ind/h, with an average of 8046.58 ind/h. The individual density of fishery resources was 65.58×10^3-589.92×10^3 ind/km^2, with an average of 297.24×10^3 ind/km^2. The biomass density of fishery resources was 428.34-1420.16 kg/km^2, with an average of 919.09 kg/km2. The dominant species were Syngnathus acus, Pholis fangi and Metapenaeopsis dalei. There were 15 important species including Callionymus kitaharae, Liparis tanakae, Lophius litulon, Heptacarpus rectirostris etc. The species richness （D）, Shannon-Wiener diversity index （H′） and evenness index （J′） were calculated based on the survey data. D was 1.400-3.255, with an average of 2.471;H′was 0.492-2.309, with an average of 1.857; J′ was 0.182-0.713, with an average of 0.596. The previous survey in 1980s showed that there were 150 species of fish in Haizhou Bay, therefore since then the diversity of fish species have greatly declined. The numbers of crustaceans and cephalopods species were also decreased compared to data （19 species of crustaceans and 6 species of cephalopods） from other researchers. The biomass and numbers of the main economical species were reduced. Small and low-value fish species and Metapenaeopsis dalei have gradually taken over the dominance. Tailfish （Trichiurus lepturus）, an economical species, was not found. These phenomena may result from over-fishing and/or anthropogenic pollutions.