The Preliminary Analysis About Fish Resources In Hongshui River Cascade Hydropower Stations

From June to September,2013,The fish resources of Hongshui River's seven cascade hydropower stations which have been completed and are applied are investigated,that are Tian Shengqiao Hydropower Station,Ping Ban Hydropower Station,Long Tan Hydropower Station,Yan Tan Hydropower Station,Da Hua Hydropower Station,Le Tan Hydropower Station and Qiao Gong Hydropower Station.Through the measurement,statistics and analysis of phenotypic traits,age and gonad's relevant parameters of 1099 fish samples which are caught,the eight main phenomenons are found.The first,during the survey period,the 66 species of fish are caught,that belong to 5 orders and 14 families 59 genera.There are 2 families 47 species to Cypriniformes which is the most species,that accounted for 71.21%of the total number of harvested fish species.Siluriformes have 4 families and 10 species,that accounted for 15.15%.Perciformes have 6 species of 7 families,that accounted for 10.61%.There are 1 families 1 species that Salmoniformes and Acipenseriformes are the same,that Accounted for 1.52%.At the family level,it is the most species to Cyprinidae whic have 42 species,that accounted for 63.64%of the total number of harvested fish species.Cobitidae species and bagrid species are the same,that have 5 species and accounted for 7.58%.Siluridae have 3 species and accounted for 4.55%.Serranidae have 2 species and accounted for 3.03%.Each family have 1 species among Clariidae,Ictaluridae,Cichlidae,Gobiidae,Mastacembelidae,Centrarchidae,Eleotridae,Salangidae and Acipenseridae,that accounted for 1.52%.The second,So far,there are 171 kinds of fishes,that are recorded to live and pass in Hongshui River,belonging to 8 orders,25 families and 103 genera.Ignoring those breeds which may live and pass in Hongshui River but are not caught,Orders,Families,Genera and species of the existing fish respective accounted for 62.50%,56.00%,57.28%and 38.60%of the recorded fish about Hongshui River Cascade Hydropower Stations.On the whole,the number of existing fish species is decreased prominently in the comparison with the number of the record fish species in Hongshui River.The third,in the survey area,there are 4867 vessels of existing professional and non professional fishing boats.The amount of fishing are 5024 tons in 2012.The amount of fishing Aristichthys nobilis,Cyprinus carpio,Erythroculter ilishaeformis,Hemiculter leucisculus,Ctenopharyngodon idellus,Mystus guttatus,Carassius auratus,Squaliobarbus curriculus,Ptychidio jordani and Silurus meridionalis accounted for about 80%of the total amount of fishing,that are the most number of population and the largest amount of fishing in the cascade hydropower stations.According to 50%of the resource exploitation rate,in 2012,the total number of fish resources were 10049 tons in Hongshui River's seven cascade hydropower stations.The fourth,in recent years,due to overfishing,and the ecological environment of waters becoming lacustrine facies from fluvial facies,Non resident fish yield decreased year by year.In a single species,in the 66 fish species which are caught,the population biomass of H.leucisculus are about 10%of the amount of fishing.The dominant sociales of fish trend of miniaturization obviously.The fifth,in recent years,as a result of fish living in cage escaping,the number of exotic fish species and population gradually increasing,and many alien species of adapting to the environment of reservoir largely breeding,the growth and breeding of native fish species are influenced.With the increasing number of respective reservoir's Tilapia,T.have a competitive advantage.In the upstream of the reservoir,the number of E.ilishaeformis population are larger than others',forming the dominant population in some reservoir.The sixth,after reservoirs being completed and retained water,the influence which the good-sized migration's fish that produce floating eggs come in for are the largest.The migration's alleyway of four major Chinese carps anda variety of freshwater fish are seriously separated,and due to reduced of oviposition site,they are forced to move to upriver the bay or the branch.Because of the dam block,floating egg cought not normal rafting and hatching.Results,the relevant water's fish diversity is descendant.The seventh,in the harvesting fish,the respective reservoir's fish age composition is simple.Many fish species are from 2 to 3 years old fish,and lack 5 years old and above fish.The fish diversity descend evidently.The eighth,through the comprehensive water quality judgment,the water quality in the respective reservoir area are II category by comparing with the"environmental quality standards for surface water".In the nutrition level,from upstream to downstream,the water quality are in nutrition type from Tian shengqiao Reservoir to Le Tan Reservoir,there are six reservoirs.Qiao Gong Reservoir's water quality is mild eutrophic type.