于2019年 9 月—2020 年 8 月,对长漾湖的鱼类群落和主要环境因子进行了调查,采用Shannon-Wiener多样性指数(H')、Margalef种类丰富度指数(d)、Pielou均匀度指数(J)、等级聚类分析和非度量多维尺度排序(NMDS),对鱼类群落结构和多样性进行了分析.结果表明,共监测到鱼类32 种,隶属于 5 目 7 科 25 属 32 种,其中鲤形目最多,占总种类数的 78.13%.长漾湖鱼类以定居性鱼类、中上层鱼类和肉食性鱼类占比较高.长漾湖第一优势种为刀鲚(Coilia nasus),其次为达氏鲌(Culter dabryi)、鳙(Aristichthys nobilis)、花(?)(Hemibarbus maculatus)、鲢(Hypophthalmichthys molitrix)和似刺鳊(鮈)(Paracanthobrama guichenoti).H'、d和J分别为 1.51~2.19、2.00~3.38 和 0.65~0.77.聚类分析表明,长漾湖各季节不同点位的鱼类群落相似性均高于 49.01%.提出,应继续加大长漾湖的渔业资源养护力度,通过放流鲢鳙等净水物种、控制陆源污染物等方式,调节湖泊水域环境质量,恢复水生植被,提高鱼类产卵效能,关注保护物种资源变化规律,从而为渔业管理提供科学依据.
A field survey of the fish in Changyang lake from September 2019 to August 2020,the structure and diversity of fish community were analyzed by using Shannon Wiener diversity index(H'),Margalef species rich-ness index(d),Pielou evenness index(J),cluster analysis,similarity percentage analysis(SIMPER)and non metric multidimensional scale ranking(NMDS).A total of 32 species of fish were monitored,belonging to 5 orders,7 fam-ilies and 25 genera.Cypriniformes had the larqest species number of species,accounting for 78.13%of the total species captured.According to the analysis of fish ecological types in Changyang lake,sedentary fish,pelagic fish and omnivore fish account for a high proportion.Coilia nasus was the first dominant species in Changyang lake,followed by Culter dabryi,Aristichthys nobilis,Hemibarbus maculatus,Hypanthhalmichthys molitrix and paracan-thobrama guichenoti.H',d and J were 1.51-2.19,2.00-3.38 and 0.65-0.77 respectively.Cluster analysis showed that the similarity of fish communities in different regions of Changyang Lake in each season was higher than 49.01%.The research results suggest that in order for the management of fishery resources to provide scientific basis in Changyang Lake,the conservation efforts of fishery resources should be strengthened by releasing clean water species of silver carp and bighead carp,controlling land-based pollutants,adjusting the water environmental quality,resuming the aquatic vegetation,improving fish spawning efficiency,and paying attention to the changing patterns of species resources protection.