长江流域的鱼类资源及其保护对策

长江水系的鱼类约有300种,其中鲤科鱼类占半数以上,主要的经济鱼类多数属于鲤科。对不同江段的鱼类资源作了简介,并提出了相应的保护措施。上游江段以维护生物多样性,保护特有种为主,需要建立鱼类自然保护区;中游应保证主要经济鱼类的自然繁殖条件,加强珍稀鱼类的人工繁殖放流工作,同时对湖泊幼鱼资源进行保护;下游应注意保持江水质量,严格遵守工业废水排放标准;河口江段应规定幼鲟保护期,建议每年6月15日至7月31日停止一切损害幼鲟资源的渔捞作业。

FISH RESOURCES OF THE YANGTZE RIVER BASIN AND THE TACTICS FOR THEIR CONSERVATION

There are about three hundred fish species in the river system of the Yangtze Riverbasin,over half of which being of the family of Cyprinidae,and most of the importanteconomic species are cyprinids.A brief account of the fish resources in the various reachesof the river is presented,and correspondent conservation measures are proposed in viewof the forthcoming construction of the Three-Gorge Dam.For the upper reaches,effortshould be directed to the preservation of the endemic species for maintaining biological di-versity,and the setting up of a nature reserve for fish species should be contemplated.In the middle reaches,the hydrological requirements for the spawning of the majoreconomic species should be compensated for,and,for the endangered species,artificalpropagation and releasing of fingerlings to the river should be strengthened;meanwhilethe protection of young fish is of much importance in most lakes.In the Iower reaches,heed is to be given to the water quality of the river,for which the criterion for thedischarge of industrial wastewater should be observed.In the estuarine area,it is prop-osed that the period from 15 June to 31 July every year be closed to certain fishinggears for the sake of saving juvenile sturgeons.