浙江北部沿岸张网作业区鱼类优势种时空变化研究

根据2007-2009年浙江北部沿岸张网作业区（29°30′～31°00′N、122°00′～123°00′E）进行监测所获得的资料,用相对重要性指数、Margalef物种丰富度指数、Shannon-Wiener多样性指数、Pielou均匀度指数等指标,对浙江北部沿岸张网作业区鱼类的季节变化、时空分布和重要经济种类生物学变化进行分析。结果表明：浙江北部沿岸张网作业区第一、二、三季度共有优势种8种,第四季度优势种7种。将调查的10个作业点划分为5个区域,其中,黄大洋、嵊泗区共出现优势种6种;普陀区和岱衢洋共有优势种5种;杭州湾有优势种3种。对黄龙点主要经济种类生物学测定和分析得出,本次调查主要经济鱼类带鱼、小黄鱼、银鲳等平均体重较历史上有较大变动,群体组成趋于小型化。

Research on Spatial and Temporal Variation of the Dominant Fish Species in the Stow Net Fishing Areas Along the Northern Coast of Zhejiang Province

According to the materials acquired by monitoring the stow net fishing areas along the northern coast of Zhejiang(29°30′-31°00′ N、122°00′-123°00′ E) from 2007 to 2009,and the analysis of the biological changes of important economic species,as well as the fishes in terms of seasonal variation,spatial and temporal distribution,by virtue of such indicators as the relevant importance index,Margale species richness index,Shannon-Wiener diversity index and Pielou evenness index.It turned out that there were totally 8 dominant species in the first,second,and third quarter in the stow net fishing areas along the northern coast of Zhejiang,7 in the fourth.The ten fishing areas investigated could be further divided into 5 regions,among which there were altogether 6 dominant species in the Yellow Ocean and Shengsi District,5 in Putuo district and Daiqu ocean,and 3 in the Hangzhou bay.Results drew from the biological survey and analysis of the important enomic species in Huanglong fishing area indicate that the average weight of the main commercial fishes investigated,i.e.Octopus,small yellow croaker and silver pomfret,had undergone greater change compared with that on historical record,and the group composition tended to be smaller than before.