大连湾海域鱼类的群落结构研究

Structure of Fish Community in Dalian Bay

采用大连湾海域四季底拖网调查数据（2006年夏、冬季和2007年春、秋季）,对其鱼类群落结构进行研究,并利用多样性指数法和丰度/生物量比较法（ABC曲线）评价鱼类群落受外界扰动的程度。研究结果表明,该海域四季共采集鱼类31种,隶属于10目24科31属,鱼类区系组成在适温性上以暖温性鱼类为主,在栖息水层上以底层鱼类为主。夏季鱼类生物量（43.16kg/h）和生物数量（950个/h）均明显高于其他3个季节。四季共有优势种为大泷六线鱼和许氏平鲉。鱼类群落多样性指数季节变化范围分别为物种丰富度指数0.76~2.16、多样性指数0.63~1.96、物种均匀度指数0.36~0.91。各季节间生物量和丰度组成的Bray-Curtis相似性均较高。多样性指数法和丰度/生物量曲线法对鱼类群落受外界扰动评价结果一致,均表明鱼类群落受到中度扰动,且秋冬季高于春夏季。本研究可为大连湾海湾生态系统健康评价和生态修复提供科学依据。

The structure of fish community were analyzed preliminarily, and the degree of disturbance was estimated through the species diversity index of fish community and the abundance/biomass curves based on the bottom trawl surveys in Dalian Bay during summer and winter in 2006, and spring and autumn in 2007. A total of 31 species were collected belonging to 10 orders, 24 families and 31 genera. Fish fauna showed that warm temperate species were dominant in water temperature tolerance, and demersal fishes were dominant in water depth of fish habitat. The biomass （43. 16 kg/h） and abundance（950 ind./h） in summer were higher than in other three seasons. Fat greenling Hexagrammos otakii and Schilegers rock fish Sebastes schlegeli were dominant species in each season. The Margalef species richness index （D） ranged from 0.76 to 2.16, the Shannon-Winner diversity index（H＇） ranged from 0.63 to 1.96, the Pielou evenness index（J＇） ranged from 0.36 to 0.91. The similarity of species compostion in Bray-Curtis were high between each two seasons. The Shannon-Winner index and ABC curves showed same results for the degree of disturbance of fish community which was moderately disturbed, and the degree was higher in au- tumn and winter than in autumn and summer. The findings can provide a scientific basic for bay ecosystem health assessment and marine ecological restoration.