一、葛洲坝枢纽对鱼类资源的影响长江流域鱼类资源十分丰富,共约有280余种(鲤科鱼类141种),其中主要经济鱼类40余种。干流各江段鱼类分布与地理环境密切相关,著名的三峡地区不仅是长江上、中游的分界处,而且是鱼类的天然分界处:上游江段多高山峡谷,水深流急,生活在这里 I. Influence of Gezhouba Dam on Fish Resources There are about 280 fish species (141 species of carp) in the Yangtze River Basin, of which there are more than 40 species of major economic fish. The distribution of fish in each section of the mainstream is closely related to the geographical environment. The famous Three Gorges area is not only the boundary between the upper and middle reaches of the Yangtze River, but also the natural boundary of fish.