Recent Status of Fishes in the Yangtze River and its Ecological Health Assessment

Abstract

The Yangtze River, ranking behind the Nile and the Amazon rivers, is the third longest river in the world. The Three Gorges Dam constructed on the Yangtze River dramatically altered the ecological environment in the surroundings. In this review, we integrated the published data about the Three Gorges Project and systematically analyzed the status of fish population in the Three Gorges Reservoir for recent fifteen years (2000~2014). Meanwhile, Fish Index of Biotic Integrity (F-IBI) system was used to assess the health risks to the ecological environment in the Three Gorges Reservoir Basin. This review indicated that the yields of natural fish catch decreased in the Yangtze River Basin (Dongting Lake, Poyang Lake, the downstream of the Three Gorges Dam and the Three Gorges Reservoir) during the recent fifteen years (2000~2014). The overall trends of natural fishing catch for Dongting Lake, Poyang Lake and the Three Gorges Reservoir went down. The fry runoff volume of four major Chinese carps in Jianli section decreased by about 80% from 2002 to 2003. In addition, the construction of the Three Gorges Dam left significant impacts on the populations of endemic fish and rare fish on the upper reaches of the Yangtze River. The F-IBI scores for the upstream Yangtze River gradually went down after 2003, but still maintained in general level. Our findings about the status of fish population and the ecological risk assessment of the Yangtze River, which will be helpful for Chinese government in decision making for the sustainable development of the Three Gorges Reservoir Area and comprehensive ecosystem management in the Yangtze River Basin.