The Fish Community Structure Dynamic Characteristics In Xingkai Lake About Nearly Fifty Years

According to fish data form8fish monitoring station in Xingkai Lake during May to October of2012and historical literature, analyzes the dynamic change characteristics of variation in fish community structure. A total of50species were found,belonging to5orders,12families38genera,of which Cyprinformes Cyprinidae were largest, there are36species, accounting for72%, which were the main categories of fauna composition in Xingkai Lake. According to the ecological type classification, pelagic fish, Omnivorous fish, Sticky eggs fish, were the main categories of fauna composition in Xingkai Lake.2012catchstatistics was about285t,and fishery production declined year by year. In recent years, the main target has gradually changed from Erythroculter ilishaeformis to Protosalanx hyalocraniu. Besides, fishing boats and fishing gear have been changed.Six kinds of dominant species were found in the survey, according to do minance in descending, the order are:Protosalanx hyalocraniu, Hemiculter leucisculus, Hemiculter bleekeri lucidus, Erythroculter dabryi shinkainensis, Erythroculter mongolicus mongolicus, Eiythroculter ilishaeformis。They accounted for12.0%of the total number of species of fish,93.5%of the total number of individuals in the populationand80.1%of the totalpopulationbiomass. According to analysis and calculation, the species diversity of large fish communities was lower. The annual Shannon-Wiener diversity index (H’) was0.9158, Pielouindex (J’) was0.1713, and Margalef index(D) was2.6192.The highest diversity index of Xingkai Lake was in spring, followed in summer and autumn. Compared with analysis of historical documents, which showed that the main features of dynamic fish community structure in Xingkai Lake was:the miniaturization offish community structure of younger age, the invasion of alien species and the failure of fisheries production.This paper analyzes and discusses the are mainly reasons for this change. Firstly, fishing and uncontrolled human activities on Xingkai Lake damaged the environment, Secondly, relevant protection recommendations are provided for the reality of Xingkai Lake fisheries resources.