舟山渔场衢山岛海域春夏季鱼类数量变化

利用2008年3月和6月衢山岛海域渔业资源调查资料,研究衢山岛海域鱼类种类组成和多样性的变化,分析主要优势种密度对鱼类总密度的贡献率。结果表明,两个航次拖网调查,共鉴定鱼类30种,其中暖温种15种,暖水种13种。3月的鮸和刀鲚,6月的六丝矛尾虾虎鱼分别是本海域较重要的优势种。3月和6月鱼类重量密度分别为125.05 kg/km2和95.01 kg/km2,尾数密度为8.41×103ind/km2和37.74×103ind/km2。鱼类重量密度与尾数密度分布趋势一致,呈现调查水域南部高于北部的分布趋势。依据贡献β值,衢山岛海域鱼类数量的变化与主要优势种数量变化有关。鱼类的种类组成与水团有着密切关系。

On the quantitative change of the fish in the sea area of Qushan island during spring and summer

Based on the data taken from two fishery resource surveyings in the sea area of Qushan island in March and June 2008,this paper dealed with the seasonal change of fish composition and diversity;analyzed the contribution the dominant species made to total fish density.There were altogether 30 species,among them 15 were warm temperate species,and 13 were warm water species.Miichthys miiuy and Coilia ectenes were dominant species in March,and Amblychaeturichthys hexanema was dominant species in June.The weight density was 125.05 kg/km2 and individual density was 8.41×103 ind/km2 in March,and 95.01 kg/km2 and 37.74×103 ind/ km2 in June.Both the weight and individual distributions showed the same tendency that the densities of the south area were higher than that of the north area in the surveying waters.Based on the value of β,We come to the conclusion that the change of fish density was related with the change of the main dominant species density;and the composition of species was closely related with the water masses.