岱衢洋产卵场鱼卵、仔稚鱼群落结构及其与环境因子的关系

为了解岱衢洋海域鱼卵、仔稚鱼的群落结构及其与环境因子的关系,本团队分别在2010年5月—2012年2月春、夏、秋和冬季,利用大型浮游生物网在此海域开展了8个航次调查。共采集到鱼卵1 042粒,仔稚鱼2 055尾,隶属于10目19科37种。鱼卵优势种为扁舵鲣和小带鱼等;仔稚鱼的优势种为鰉、鳀和中华小公鱼等。调查海域鱼卵的平均密度是8.40粒/100 m3,仔稚鱼的平均密度是14.85尾/100 m3。单因素方差分析结果显示,2010年和2011年春、夏季4个季节之间丰富度指数(D)、均匀度指数(J′)和多样性指数(H′)均存在极显著差异。鱼卵、仔稚鱼资源密度分布不均匀,春、夏季较高,冬季最低,大体呈现南高北低的趋势。Pearson相关性结果分析得出,与鱼卵、仔稚鱼关系最密切的环境因子为温度、盐度和海水悬浮物。研究表明,春、夏季是岱衢洋海域鱼类产卵的重要时期,该海域是鳀、扁舵鲣、中华小公鱼等中上层鱼类的重要产卵场和育幼场。

Community structure of ichthyoplankton and its relationship with environmental factors in Daiquyang spawning ground

The ichthyoplankton net was used to carry out the survey of fish eggs and larvae of Daiquyang between May 2010 and February 2012. According to the investigation results, 1 042 fish eggs and 2 055 fish larvae were collected, which belonged to 10 orders 19 families 37species. The dominant species of fish eggs were Auxis thazard and Eupleurogrammus muticus while fish larvae were Liza haematocheilus, Engraulis japonicas and Stolephorus chinensis. The average density of fish eggs in the surveyed areas was 8.40 ind./100 m³ while fish larvae was 14.85 ind./100 m³. The results of One-Way ANOVA showed that there were highly significant differences among the diversity index (H'') in 4 seasons of spring and summer from 2010 to 2011, so were in the evenness index (J'') and richness index (D). The CPUE of fish eggs and larvae showed uneven distribution, it was higher in spring and summer, but lowest in winter, which revealed that fish eggs and larvae resource density demonstrated a tendency of higher in the south stations and lower in the north stations. Pearson correlation analysis proved that the environmental factors most closely related to fish eggs and larvae were temperature, salinity and suspended matter. The results suggested that spring and summer were important seasons for fish spawning and Daiquyang areas were important spawning and nursery grounds for pelagic fishes such as E. japonicas, A. thazard and S. chinensis.