Status of research on Yangtze fish biology and fisheries

The Yangtze is the largest river in China and the third largest river in the world. Being pregnant with plentiful fish resources, it is not only the representative of the areas with biological diversity, but also a cradle of freshwater fisheries in China. In the Yangtze, at present, the fishery resources are seriously depleted; the fishery yield by fishing is significantly reduced; significant changes have occurred on the structure of fish community, with decrease in migratory fish species, reduction in the quantity of the populations of rare, peculiar and economically important fish species and increase in the number of exotic fish species, and severe trend in fish stunting. Habitat fragmentation and shrinkage, resources overexploitation, water pollution and invasion of exotic species are the main causes for threatening fish stocks in the Yangtze River. Since 1950's, a lot of scientific researches have been conducted on biology of fishes from the Yangtze River and its fisheries to provide scientific basis for their protection. In recent years, measures such as closed spring, fish reserves, artificial enhancement & release, ecological rehabilitation, fishery management and international cooperation have played important roles. Nevertheless, researches on fishes from the Yangtze cannot adequately meet the demand for their protection. Especially, those in the aspects of population ecology of Yangtze fishes, species endangerment mechanism, ecological effects of large hydraulic projects and protection strategy are not deep enough. It is recommended that scientific researches should be conducted in comprehensive survey of Yangtze fish resources, fish endangerment mechanism, techniques in artificial enhancement and release of key species, risk assessment of exotic species, ecological rehabilitation of major fisheries functional zones, etc.