长湖鱼类群落结构的时空变化

为系统阐明长湖鱼类群落结构特征,2014年3~11月对长湖鱼类群落结构的空间差异和季节动态进行了较为全面的调查。结果表明,长湖共调查到鱼类43种,隶属于7目14科37属,主要为湖泊定居型鱼类;大湖区和海子湖区鱼类优势种组成虽存在一定的差异,但鲫、鰐、鲤和达氏鲌为两个湖区的共同优势种;长湖鱼类群落的Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数分别为0.53~2.30、0.52~2.02和0.24~0.66,除丰富度指数外,均表现为5月或8月相对较高;聚类和MDS排序分析结果表明长湖鱼类群落分为两大类群,呈现显著的时空异质性;ABC曲线显示长湖优势鱼类以小型鱼类或大型鱼类的幼体为主,且已受到不同程度的干扰。针对长湖鱼类资源已出现衰退,建议在拆除围网/拦网养殖、取缔有害渔具的同时,考虑增殖放流、栽种水生植物等措施来达到长湖鱼类资源保护和可持续利用的目的。

SPATIAL-TEMPORAL VARIATION OF FISH COMMUNITY STRUCTURE IN LAKE CHANGHU

In order to illustrate fish community structure of Lake Changhu, spatial and temporal variation of fish communities were investigated seasonally from March to November 2014. The results indicated that: in Lake Changhu, 43 species belonging to 7 orders, 14 families and 37 genera were collected, most of which were lake resident species; there were different dominant species between two lake regions, but Carassius auratus, Hemiculter leucisculus, Cyprinus carpio and Culter dabryi were their common dominant species; Ranges of Margalef species richness index, Shannon-Wiener diversity index and Pielou evenness index of fish community in Lake Changhu were from 0.53 to 2.30, from 0.52 to 2.02, and from 0.24 to 0.66, respectively; Except for species richness index, other diversity indices were relatively higher in May or August; Hierarchical analysis and MDS analysis revealed that there were two different fish communities based on their spatial and seasonal variation of fish abundance in Lake Changhu; ABC plot showed that dominant fish species of Lake Changhu were mainly small fish or young individuals of large fish, and fish community had been disturbed. In view of declining fish resources in Lake Changhu, it was suggested that removing enclosure culture and banning harmful fishing gear, along with enhancement-release technology and aquatic plants planting technology, were essential for the conservation and sustainable utilization of fish resources in Lake Changhu.