春季东海有害藻华高发区仔稚鱼时空分布

Spatio-temporal distribution of larval and juvenile fishes at frequent harmful algal blooms(HABs)areas of the East China Sea in spring

根据2011年春季（3月29日—5月27日）海洋综合调查,对东海有害藻华高发水域（28°15′36″~30°30′16″N、121°52′36″~123°15′6″E）的仔稚鱼种类组成、时空分布以及主要优势种与环境因子的相关性进行了探讨。调查共采集到仔稚鱼27种,前几位优势种分别为日本鳀Engraulis japonicus、鰕虎科sp.（Gobiidae sp.）、六丝钝尾鰕虎Amblychaeturichthys hexanema、小黄鱼Larimichthys polyactis,该4种占据了总丰度的91.23%。优势种丰度和发育阶段组成的时空变化显示,日本鳀在调查期间有两次产卵小高峰,其仔鱼孵化后向岸漂流;小黄鱼和六丝钝尾鰕虎在此期间只有一次产卵高峰,其仔鱼在舟山群岛邻近水域进行保育。可以看出,调查水域及邻近水域是部分鱼类产卵,仔稚鱼保育、向岸漂流的场所或途径,是鱼类早期生活史中重要生境,一旦暴发有害藻华,补充群体将受到不良影响。多元分析结果显示,所选环境因子对几位优势种仔稚鱼的分布影响不大,推测产卵场位置和保育方式可能是更重要的原因。

Based on an oceanographic comprehensive survey at the frequent HABs area in the East China Sea from March 29 th 2011to 27 th May 2011,species composition,spatio-temporal distribution and relationship with environmental factors were discussed.A total of 27 species were collected.The top abundant species include Engraulis japonicas,Gobiidae sp.,Amblychaeturichthys hexanema,Larimichthys polyactis,comprising 91.23% of the total catches.According to the spatio-temporal distribution of abundance and developmental stages composition,E.japonicas showed two spawning peaks and indicated a trend of inshore drifting,while A.hexanemaand L.polyactis had only one spawning peak and utilized Zhoushan archipelago as nursery ground.These larval and juvenile fishes utilize this area for spawning,nursing and inshore drifting respectively,once HABs occur,the recruitment would be negatively affected.Multivariate analysis showed no significant relationship between larval and juvenile fish assemblages and involved environmental factors,the location of spawning ground and nursing pattern may be more important reasons.