南四湖鱼类群落对南水北调东线工程的响应

The Responses of Fish Community of Nansi Lake to the East Route of the South-to-North Water Transfer Project

通过对南水北调东线工程中的调蓄枢纽南四湖进行考察发现,到2006年为止,南四湖仅存鱼类32种.简要分析了1987年至2006年南四湖鱼类的衰退状况及其形成驱动力.根据调水状态下,南四湖水环境将会发生的变化,系统探讨了南水北调东线工程对南四湖鱼类资源的可能影响.结果表明,二期工程鱼类物种的多样性会有一定程度的提高;调水期对鱼类的影响较大,而鱼类年产量不会有太大的波动;种群比例差距会有一定程度的缩小,但是鱼类的优势种群不会发生变化.为了尽快使鱼类资源增殖,从而达到水生态系统的平衡,还提出了提高保护鱼类资源意识、严格控制捕鱼程度、建立渔业环境和资源长期监测系统等措施,供南水北调决策和设计部门参考.

Nansi Lake is the hinge possessing important strategic significance in the east route of the south-to- north water transfer project. Until 1998, there are only thirty-two species of fish in Nansi Lake. This paper makes first the brief analysis on the decline of fish resource and its cause of Nansi Lake from 1987 to 1998. According to the change of aquatic environment, which might occur in Nansi Lake under the tramper state, the possible influence of the second phase project on the lake fish community is analyzed systematically. On the second phase project, the species diversity of the fish will increase to some extent, the effect of engineering to fish resources is relative larger during the period of water transfer, however, the annual yield of fish will not have oversize fluctuation, the disparity of the community proportion will be lessened to some extent, and the superiority population of the fish will vary little. In order to proliferation of fish resources and achieve the balance of water ecosystem, some corresponding strategies were proposed. We should take actions to heighten consciousness of protection of fish resources, to strictly control the degree of fishing as well as establishing lasting monitoring system for fisheries environment and resources. These strategies are referential in making a strategy and for the design of the South-to-North Water Transfer.