舟山渔场金塘岛海域春夏季的鱼类群落

为了揭示金塘岛附近海域渔场鱼类资源特征,利用2009年5月和9月在舟山渔场金塘岛水域获得的渔业资源调查资料,研究金塘岛水域鱼类密度的时空分布,分析种类组成、优势种、种类数和多样性等群落结构等指标的变化特征,分析这些特征所反映这一水域的渔场属性。结果表明:5月和9月鱼类重量和尾数密度分别为47.51kg.km-2、3.44×103ind.km-2和92.50kg.km-2、20.51×103ind.km-2;鱼类重量密度与尾数密度分布趋势基本一致,呈现出近舟山群岛一侧的东部水域鱼类密度高于西部水域的趋势;5月和9月龙头鱼(Harpodon nehereus)是本海域最重要的优势种,几乎为幼体组成,而凤鲚(Coilia mystus)是次要优势种。总体上,两季平均鱼类幼体比例高达86%,显示出这一水域是鱼类的产卵场和育幼场;鱼类种类数夏季高于春季;种类数与多样性的分布格局相似,也是舟山群岛一侧的东部水域鱼类密度高于西部水域。可以认为,近金塘岛一侧海域是经济幼鱼的索饵场。

Fish community in Jintang Island sea area of Zhoushan fishing grounds, Zhejiang Province of East China in spring and summer

Based on the survey data of fish resources in the Jintang Island sea area of Zhoushan fishing grounds in May and September,2009,this paper studied the spatiotemporal distribution of fish density,and analyzed the fish community structure,such as species composition,dominant species,species number and diversity,aimed to explore the attributes of the fishing grounds in this sea area.In May and September,the fish weight and density were 47.51 and 92.50 kg·km-2,and 3.44×103 and 20.51×103 ind·km-2,respectively,and their spatial distribution patterns were basically the same,being higher in the eastern than in the western water areas near the side of Zhoushan Islands.Harpodon nehereus was the most dominant species,and was mainly composed of young individuals,whereas Coilia mystus was another dominant species.Overall,the proportion of the young fishes in spring and summer was averagely up to 86% of the total,indicating that Jintang sea area was a good spawning ground of fish.The fish species number was higher in summer than in spring.Both the fish species number and the fish diversity also had the similar distribution pattern,i.e.,higher in the eastern than in the western water areas near the side of Zhoushan Islands.It was considered that Jintang sea area was an ideal feeding ground for economic fishes.