青草沙水库中上层鱼类群落组成及多样性分析

为了解青草沙水库正式供水后的鱼类群落组成、多样性及时空分布特征,于2011年5月、7月、10月和12月,将水库分成3个区域(西区、对照区和放养区)进行本底调查。调查期间共捕获鱼类22种,隶属于5目7科,以鲤科鱼类为主;鱼类群落分为3个生态类型,淡水鱼类17种、河口性鱼类3种和洄游性鱼类2种。群落优势种为刀鲚(Coilia ectenes)、鲫(Carassius auratus)、鲤(Cyprinus carpio)和光泽黄颡鱼(Pelteobagrus nitidus)。水库的西区水域宽阔,水草丰富,鱼类多样性和丰富度最高;各季节的多样性中以春季为最高,冬季最低。聚类分析显示水库的鱼类群落组成时间和空间上存在显著差异。青草沙水库的修建及水库内盐度的下降,近海和河口性鱼类减少,可能是鱼类多样性下降的主要原因,小型鱼类占主导,建议增殖放流时加大大型鱼类苗种的投放。

Community composition and diversity of pelagic fishes in Qingcaosha Reservoir

To explore the fish species composition, biodiversity and spatial and temporal characteristics of fish assemblages for a water supply reservoir, Qingcaosha reservoir, the background survey was operated in three regions (western waters, control waters and stocking waters) of Qingcaosha waters and there were four sampling sites in each region in May, July, October and December in 2011. A total of 22 species were collected, belonging to 7 families, 5 orders, and Cyprinidae was the most abundant. The community was composed of three ecological types: freshwater (17 species), estuarine (3 species), diadromous(2 species), and freshwater species were absolutely dominant. In all species, the dominant species were Coilia ectenes, Carassius auratus, Cyprinus carpio and Pelteobagrus nitidus. The highest diversity and richness region was western waters. The diversity of spring was the highest, and that of winter was the lowest. Cluster analysis showed that there were significant differences in the fish communities among the sampling sites and between seasons. Reservoir construction and decreased salinity resulted in the fact that the fish diversity decreased and the small-size fishes became dominant. so it is suggested that the delivery of large-size fishes should be increased in the activity of fishery enhancement and release.