钱塘江富阳段鱼类资源现状

2014年11月—2015年12月对钱塘江富阳江段3个断面鱼类资源进行了逐月采样调查,对该水域鱼类种类组成、优势种、群落多样性指数和捕捞量进行分析。结果显示:共采集鱼类48种,隶属8目13科37属,其中鲤科鱼类种类最多,占总种类数的64.58%,优势种为鲢、鲤、鲫和光泽黄颡鱼。各月中,4月份捕获的鱼类种数最多,占总种数的52.08%;9月份鱼类捕获量最高,占总渔获量的17.85%。Margalef丰富度指数4月份较高,2月份较低;Shannon-Wiener多样性指数和Pielou均匀度指数在7月份较高,9月份较低,而Simpson多样性指数与之相反。富阳段鱼类捕捞强度较大,渔获物中小个体鱼类占主要部分。与历史记录比较,富阳江段鱼类群落组成已经发生了显著变化,除本地种光泽黄颡鱼外,增殖放流鱼种已成为了优势或重要种群。

Current status of fishery resources in Fuyang section of Qiantang River

A monthly investigation was conducted on the fishery resources at 3 sampling sections in Fuyang section of Qiantang River from November 2014 to December 2015, and the fish species composition, dominant species, community diversity index and catch were analyzed.A total of 48 species were collected, which belonged to 8 orders, 13 families, 37 genera, and Cyprinidae had the largest number of species, which constituted 64.58% of the total species number.The dominant species were Hypophthalmichthys molitrix, Cyprinus carpio, Carassius auratus and Tachysurus nitidus.The species number and biomass of fish community displayed obvious variation with month, with the largest number in April and the highest biomass in September.The Margalef diversity index, Shannon-Wiener diversity index, Pielou diversity index and Simpson diversity index also showed obvious monthly variations,with the highest values in April, July, July and September, respectively.The fishing intensity was comparatively large, and the small-sized and medium-sized fish were the mainly compositions of catches.The fish community in the survey regions changed obviously compared with the historical records, and the proliferation and releasing fish species had become dominant or important populations except for the local species named Tachysurus nitidus.