Patterns Of Fishes Diversity In Jialing River And Resources Vicissitude In The Middle And Lower Basin

The Jialing River flow through Shanxi Province, Sichuan Province and Chongqing City, it across about 16 million square kilometers drainage area and is an important tributary of the Yangtze River. The Jialing River is rich in fish resources.Currently, the Navigation and Hydropower project is carried on in the Jialing River. This will improve the waters and the ecological status of the Jialing River. But there lack analysis of resources, fish species and floristic composition from the perspective of the whole Jialing River. This paper analyzed fish species, floristic composition and presence from the perspective of the entire basin of the Jialing River and obtained much information on the fish resources of the Jialing River from the overall perspective.Based on previous information and field survey, this paper improved the fish resource data of the Jialing River. There exist 151 kinds of fish, divided into 7 orders, 19 families and 83 genera, of which 51 species are endemic to the Yangtze River. By analysis, the Jialing River fish fauna composition is consistent with its location and characteristics of the composition of the Yangtze River. From the composition of the fish fauna the East China plain dominate. In order to study on the Jialing River from the overall perspective, we analyzed its ecological habits and found that 60% fish live in the bottom of the Jialing River. Food is dominated by animal diets and the breeding season focus on the April, May and June. We recommend adjusting the closed fishing seasons, which will be of great benefit to develop fish resources of Jialing River, protect and restore its ecological environment. Traditionally, the Jialing River is divided into upper, middle and lower part. But according to this study we found that the construction of large hydro-power station, the non-natural barrier of river and alteration in the environment of waters changed the original section. According to fish cluster analysis, geographic barrier has not caused too much influence on the fish distribution of the Jialing River. However, the specific water environment is the decisive factor for the fish distribution. Therefore, the fish in the upstream should be given priority protection. Meanwhile, to protect and restore fish resources of the Jialing River, implementation of related policies, biodiversity conservation advocacy and strict control of fishing should be implemented.This paper further analyzed relationship between basin diversity and fish diversity. Basin diversity is an important prerequisite for fish diversity. However, there lack depth study on relationship between the two. According to our research basin diversity and fish diversity is directly proportional. According to our selected 8 indicators, the results of cluster analysis are consistent with samples diversity index analysis. On this basis, we proposed several suggestions to protect and restore the landscape characteristics of the Jialing River.The Jialing River is rich in fish resources. After field study and analysis we found the 76 species of fish, which are fishing object, belong to 10 families. According to statistics from the data and the views of fishermen along the river, Jialing River's main economic fish include Xenocypris davidi, Mystus macropterus, Cyprinus carpiod and Carassius auratus et al. By comparing with 1980's fisheries resources survey data we found major economic fish species have changed. Due to over fishing and the barrier of water project construction, some economic fish have become rare and the composition of the major economic fish lack diversity. Currently the total amounts of fish resources don't show significant reduction. However, if such over-exploitation continued the fish resources will be exhausted.The Jialing River fishery resources assessment survey reported that the fishermen living in the Jialing River lack adequate knowledge of biological diversity, fish diversity, ecosystem diversity and even the river for their survival because of their lower education level and the desire of gain. But on the whole, survey truly reflected the fishermen's attitude of aquatic environment and fish resource conservation.