The impacts of enclosure aquaculture on fish community inthe Huayanghe Lake

A large number of natural lakes have experienced severe disturbances of the enclosure aquaculture for fish farming purposes. Nevertheless, the impacts of the enclosure aquaculture on fish fauna are still largely unknown. We hence evaluated the impacts of enclosure aquaculture on fish communities based on seasonal fishery survey in enclosure (EA) and non-enclosure aquaculture area (NEA) in the Huayanghe Lake in 2016. A total of 46 (belonging to 6 orders, 12 families, 35 genera) and 57 fish species (belonging to 6 orders, 11families, 40 genera) were collected in EA and NEA, with dominant Cyprinidae accounting for 65.22% and 63.16% of the total respectively. The dominant species in NEA were Hemiculter leucisculu and Coilia brachygnathus while Hypophthalmichthys molitrix and Aristichthys nobilis were dominant in EA. The percentage of riverine species in EA declined from 21.05% to 15.22% compared with NEA. The Richness index, fish density and the Margalef’s diversity index were significantly lower, whereas the Pielou’s diversity index were significantly higher in EA than in NEA. The fish fauna differences between EA and NEA were determined by the abundance of Coilia brachygnathus, H. leucisculus, Cyprinus carpio, Neosalanx tangkahkeii, Carassius auratus, Hemirhamphus kurumeus, H. molitrix and A. nobilis.