淀山湖鱼类多样性分析

Analysis of the fish species diversity in Dianshan Lake

2006年5-12月,对淀山湖进行了5次刺网调查和3次拖网调查,收集鱼类样本1983尾,隶属9科18属、23种,多数种类属鲤科鱼类。优势种为刀鲚、鲫和子陵吻鱼叚虎鱼分别占样本个体总数的40.09%、20.52%和10.29%。人工放养的鲢、鲫、鲤、鳙是淀山湖目前主要的经济种类。多样性指标选择种类丰富度、平均种类丰富度、多样性指数、均匀度指数、优势度指数、相对稀有种类数。目前的多样性指数为1.8996,比1959年调查的下降了49%,均匀度也相应降低,优势度则由1959年的0.034上升为0.2264。水质污染等环境的恶化,加上过度捕捞等人为因素,使淀山湖鱼类物种多样性正逐渐降低。

A total of 1983 fish individuals, representing 23 species from 18 genuses 9 families, were collected auratus and Ctenogobius giurinus, accounting for 40. 09%, 20. 52% and 10. 29% of total samples respectively. Hypophthalmichthys molitrix, Carassius auratus, Cyprinus carpio, Aristichthys nobilis were the main economic species, whose fry come from aquaculture. Diversities of fish were represented by species abundance, average abundance, diversity index, evenness index, dominant index and relative rare species. Current diversity index was 1. 899 6, 49 % lower than that in 1959. Evenness index showed a decreasing tendency. The dominant index had increased from 0. 034 in 1959 to 0. 226 4. The fish species diversity has been declining, which may be attributed to the deterioration of habitat environment and effect of human activity such as overfishing.