2020年洞庭湖水生生物群落结构特征及水生态评价研究

Community structure of hydrobiology and water ecological assessment of Dongting Lake in 2020

为了解洞庭湖水生生物群落结构并进行水生态评价,在2020年采用Shannon-Wiener指数对洞庭湖浮游植物、浮游动物和底栖动物进行调查,并采用水生态环境质量综合指数法(WQI)对洞庭湖进行水生态评价。结果表明:①洞庭湖浮游植物共检出6门73属,优势种类有伪鱼腥藻(Pseudanabaena sp.)、直链藻(Melosira sp.)、尖头藻(Raphidiopsis sp.)、平裂藻(Merismopedia sp.)和十字藻(Crucigenia sp.),全湖平均密度为95.7×10^(4)个/L。②洞庭湖浮游动物共检出48属,优势种是广生多肢轮虫(Polyarthra vulgaris)、螺形龟甲轮虫(Keratella cochlearis)、象鼻蚤(Bosmina sp.)以及无节幼体(nauplius),全湖平均密度为74个/L。③底栖动物共检出57种,优势种类有指突隐摇蚊(Cryptochironomus rostratus)、多足摇蚊(Polypedilum sp.)、铜锈环棱螺(Bellamya aeruginosa)、河蚬(Corbicula fluminea)、苏氏尾鳃蚓(Branchiura sowerbyi)和钩虾(Grandidierella sp.),全湖平均密度为141个/m^(2)。④洞庭湖总体水质为轻度污染,主要超标项目为总氮、总磷。综合营养状态指数为46.87,为中营养。洞庭湖生境质量评价结果为92分,为中等。⑤洞庭湖水生态环境质量为良好。

To grasp the community structure of hydrobiology and assess water ecological of the Dongting Lake,two surveys of hydrobiology in Dongting Lake were carried out in 2020.The comprehensive index of water ecological environmental quality was used to evaluate the water ecology.The results showed that a total of 6 phyla and 73 genera of phytoplankton were detected in Dongting Lake,the dominant species were Pseudanabaena sp.,Melosira sp.,Raphidiopsis sp.,Merismopedia sp.and Crucigenia sp..The average density of phytoplankton was 95.7×10^(4)/L.A total of 48 genera of zooplankton were detected in Dongting Lake,the dominant species were Polyarthra vulgaris,Keratella cochlearis,Bosmina sp.and nauplius.The average density of zooplankton was 74/L.A total of 57 species of benthos were detected,the dominant species were Cryptochironomus rostratus,Polypedilum sp.,Bellamya aeruginosa,Corbicula fluminea,Branchiura sowerbyi and Grandidierella sp..The average density of benthos was 141/m^(2).The overall water quality of Dongting Lake was lightly polluted,the main item exceeding the standard was the total phosphorus.The comprehensive nutritional status index was 46.87,indicating the moderate nutrition.The evaluation result of habitat quality in Dongting Lake was 92,indicating the medium nutrition.WQI index was used to evaluate the water ecology of Dongting Lake,the results showed that the water ecological environment quality of Dongting Lake was good.