The current situation of fish resources in the Daning River after the impoundment of the Three Gorges Reservoir

A survey aiming at the species composition,diversity and distribution of the fish was taken in the Daning River during May and June in 2011 and 2012,October and November in 2010 and 2011.A total of 129 boats were investigated,393.8kg fish were captured and 11569 samples were measured.There were 68 species which belongs to 5 families and 13 genera.The main dominant species were Ctenopharyngodon idella,Hypophthalmichthys molitrix,Aristichthys nobilis,Peltevbagrus nitidus,Peltevbagrus vachellii,Silurus asotus,Schizothorax prenanti,Zacco platypus.Fish composition,community similarity,dominant species and biological diversity of three sample sites were analyzed.The results showed that the change of river habitat had obviously influenced the structure of community fish in the lower reaches of the Daning River.The abundance of Coreius heterodon and Coreius guichenoti,which ever were the main species in the Three Gorges reservoir,had been decreasing;The number of Silurus asotus,Cypprinus carpio and Pseudobagrus fulvidraco had been increasing;The catches in different sections of the river were different,and the number of small individual had been getting more.