南昌市13个湖泊的鱼类群落结构及其物种多样性特征

为了解南昌市面积1 km2以上湖泊的鱼类群落结构及其物种多样性特征，探究影响湖泊鱼类群落结构空间分布的环境因子，于2019-2020年在南昌市13个湖泊进行了鱼类资源调查。结果显示，采集到的39种鱼类隶属5目、9科、33属；优势种以鲫（Carassius auratus）、?（Hemiculter leucisclus）为主；不同湖泊的鱼类群落结构被划分为3个类群，与湖泊功能定位密切相关。鱼类Shannon-Wiener多样性指数值平均值为2.15，丰富度指数平均值为2.97，均匀度指数平均值为0.92，Shannon-Wiener多样性指数、丰富度指数与湖泊面积、水深、pH和透明度存在显著的相关性。冗余分析（RDA）表明，水深、pH、总氮和氨氮是引起鱼类群落结构在南昌市不同湖泊间差异的主要影响因子，人为活动干扰可能对调查区域内湖泊的鱼类群落结构和生物多样性特征施加影响。

Fish Community Structure and Species Biodiversity in 13 Lakes of Nanchang City

Nanchang City is an important city along the middle reach of Yangtze River and is rich with lakes and rivers. In this study, we investigated the fish community structure and species diversity of 13 lakes in Nanchang City and explored the environmental factors significantly affecting the spatial distribution of the fish community structure in these lakes. The aim was to provide basic data to support the protection and sustainable use of fish resources in the primary lakes of Nanchang City. In April and October of 2019 and 2020, fish and environmental surveys were conducted in 13 lakes with an area of more than 1 km2. Body length and weight of fish specimens were measured and species were identified. All specimens were classified according to habitat and diet. Water parameters monitored included Secchi depth (SD), dissolved oxygen (DO), pH, total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH4-N), nitrate nitrogen (NO3-N) and chemical oxygen demand (COD). A total of 39 fish species from 33 genera, 9 families and 5 orders were collected from the surveyed lakes, with absolute dominance by Cyprinidae (29 species, 74.4%). Carassius auratus and Hemiculter leucisclus were the dominant species in most lakes. The fish community structures of the 13 lakes clustered into three groups, closely related to the ecology function of the lakes. Group 1 included the Qingshan, Aixi and Yaohu Lakes, with the primary function of entertainment and landscape. Group 2 were the larger lakes in the suburbs of Nanjing City, including Junshan and Chenjia Lakes. The remaining lakes were small, with the primary function of aquaculture, including Qianhu, Jihu, Fangxi, Shangchi, Kanxia, Dasha, Xiazhuang and Yaogang Lakes. The average values of the Shannon Wiener diversity, Margalef richness and Pielou evenness indices of fish species were 2.15, 2.97 and 0.92, respectively. The Shannon Wiener diversity index and richness index were significantly correlated with lake area, water depth, pH and transparency. Redundancy analysis (RDA) shows that pH, water depth, TN and TP were the primary environmental factors significantly affecting fish distribution in surveyed lakes. Human disturbance was the most important factor causing simplification of fish community structure and decreased species biodiversity in the lakes surveyed.