上海苏州河鱼类群落的初步研究

A preliminary study on fish communities in Suzhou Creek, Shanghai

苏州河是一条流经上海市区的过境河流.本研究试图以鱼类群落状况来评估该河的环境质量.将2001年采集到的鱼类标本与20世纪60年代上海科技馆(旧名上海自然博物馆)的收藏标本进行对比.1960年代,鱼类物种数有62种,2001年为44种,前后减少18种;其中鲤科鱼类中营底栖生活、食无脊椎动物的鮈亚科鱼类变化明显,减少6种.鱼类的食性结构也发生了明显的变化.食鱼性鱼类的物种比例由1960年代的27.4%下降到2001年的22.7%;食无脊椎动物鱼类的比例由1960年代的24.2%下降到2001年的11.4%,而杂食性鱼类的物种比例则由1960年代的25.8%上升到2001年的38.6%.杂食性鱼类在个体数也占据优势.沿程分布显示上游的物种多样性明显高于下游.以上结果表明苏州河的鱼类群落变得简单,食物网复杂度降低,生物完整性下降,推测其主要原因可能在于作为水生生物栖息地主要构成的底质状况发生了改变.

Suzhou Creek is an urban river across Shanghai City and its adjacent areas. In the present study the river environmental quality was assessed based on fish communities. The specimens sampled in the year 2001 were compared with those collected in Shanghai Science and Technology Museum （formerly Shanghai Museum of Natural History） in the 1960s. The number of species decreased from 62 in the 1960s to 44 in 2001, with the most prominent decrease in the species of Gobiouinae that are benthos and insectivores. Marked change was also seen in trophic dominance. Percentage of species as piscivores decreased from 27.4% in the 1960s to 22.7% in 2001, and insectivores from 24.2% in the 1960s to 11.4% in 2001. On the other hand, the percentage of species as omnivores increased from 25.8% in the 1960s to 38.6% in 2001 and turned to be prominent dominance. The diversity of species in the upper stream is higher than that in the downstream. Such changes indicate that the food web was simplified and the biological integrity was decreased. It is inferred that the creek substrate degrading has caused the changes in the habitats of the aquatic creatures in Suzhou Creek.