湖南大通湖浮游动物群落结构特征与水质评价

Characteristics of community structure of zooplankton and bioassessment of water quality in the Datong Lake in Hunan, China

浮游动物是湖泊生态系统的重要组成部分,在能量流动和物质循环中发挥着重要作用,同时还是水质评价的良好指示生物。为了解湖南省大通湖浮游动物的群落结构特征,2019年6月对该水域浮游动物的种类组成、多样性以及群落结构进行了调查分析,并利用现存量、指示生物和生物多样性指数法对水质进行了评价。结果表明,共鉴定出浮游动物104种,隶属3门60属。其中原生动物47种,占总种数的45.2%;轮虫23种,占总种数的22.1%;桡足类18种(不包括无节幼虫),占总种数的17.3%;枝角类16种,占总种数的15.4%。调查水域浮游动物平均丰度为19616.47ind.·L^(-1),平均生物量为6.43 mg·L^(-1)。优势种为8种原生动物,分别是美拟砂壳虫(Pseudodifflugia gracilis)、泥炭刺胞虫(Acanthocystis turfacea)、大弹跳虫(Halteria grandinella)、砂表壳虫(Arcella arenaria)、绿急游虫(Strombidium viride)、盖厢壳虫(Pyxidicula operculata)、瓶砂壳虫(Difflugia urceolata)和冠帆口虫(Pleurimema cornatum),轮虫、枝角类和桡足类不构成优势种。物种丰富度指数为2.46—4.74,均匀度指数为0.52—0.73,香农—威纳指数为1.75—2.62。通过现存量评价法、生物指示法和生物多样性指数法评价大通湖水质为轻度—中度污染,其中部分水域为富营养状态。

Zooplankton are fundamental components in lake ecosystems and play important roles in energy flow and matter cycling.Meanwhile,zooplankton are good indicators for bioassessment of water quality.In order to reveal the community characteristics of zooplankton,species composition,biodiversity and community structure of zooplankton were investigated in the Datong Lake,Hunan Province in June 2019.Water quality was evaluated using the existing stock,indicator species and biodiversity index.Results showed that a total of 104 species of zooplankton were identified,belonging to 60 genera in 3phyla.There were 47 species of Protozoa,accounting for 45.2%of the total species number;23 species of Rotifera,accounting for 22.1%;18 species of Copepoda (excluding nauplii),accounting for 17.3%;16 species of Cladocera,accounting for 15.4%.The average abundance and biomass of zooplankton were 19616.47 ind.·L^(-1)and 6.43 mg·L^(-1),respectively.There were 8 dominant species,all belonging to Protozoa (Pseudodifflugia gracilis,Acanthocystis turfacea,Halteria grandinella,Arcella arenaria,Strombidium viride,Pyxidicula operculata,Difflugia urceolata and Pleurimema cornatum).There were no dominant species belonging to Rotifera,Copepoda or Cladocera.The values of species richness index,evenness index and Shannon-Wiener diversity index of the zooplankton community were 2.46-4.74,0.52-0.73 and1.75-2.62,respectively.Based on existing stock of zooplankton,indicator species and biodiversity assessment,the water quality of Datong Lake was under light-to-moderate pollution and some sites were in eutrophication status.