Investigation On Present Situation Of Fishery Resources In Wuqiangxi Reservoir, Hunan Province

This paper took Wuqiangxi Reservoir in Hunan Province as its research object,an investigation on physiochemical features of water quality and bait biological changes were conducted in Wuqiangxi Reservoir during 2007.On the basis of these investigations the trophic type and present situation of fishery resoures were evaluated in order to provide theoretical base for the reasonable utilization of fishery resource and ecological management of environment. The main results obtained were as follows:1.Water physio-chemical characteristicsThe change range of average temperature of the waters is 18.42-29.02℃from summer to autumn.The change range of the transparency is 0.73-0.98.The average content of DO was above 7 mg/L;the mean concentration of TN was 1.29 mg/L;the highest concentration of TP was 4.16mg/L,So the water quality of Wuqiangxi Reservoir was subordinated to super-trophic type.2.PhytoplanktonThere were 70 species of phytoplankton belonging to 7 phyla.The average density was 1952400 ind./L in a year.The dominant species were C.affinis,C.stelligera,M.Varians C.A.. Ag,Diatoma vulgare,C.moniliforum,Stigeoclonium sp.,M.glauca,Chroococcs sp.,D. bavarium and etc。3.Zooplankton70 species of zooplankton were observed and 14 dominant species such as Difflugia urceolata,Difflugia corona,Amoeba sp,Holophrya simplex,Stentor sp,Keratella valga, Brachionus calyciflorus,Daphnia hyaline,Bosmina longirostris,Alona rectangular,Chydorus sphaericus,Mesocyclops leuckarti,Phyllodiaptomus tunguidus,Canthocamptus sp.ant etc.The average density and biomass of zooplankton were 5082 ind./L and 6.734 mg/L,respectively.4.Fixed algae17 species of fixed algae were observed.The five dominant genera were Navicula dicephala,Nitzschia amphibia,Anabaena sp.,Oscillatoria princes,Oscillatoria tenuis.5.Benthic animals13 species of benthic animals were observed.The ten dominant genera were Radix, Sphaerium,Galba,Corbicula fluminea,Dixa,Tipulidae,Chaoborus,Polypedilum,Tendipes semiredus,Limnodrilus.6.Ichthy67 ichthy species belonging to 11 families and 7 oder were observed,among which the cyprinid accounts for 13 species.The fish fauna is mainly the complex of Chinese rivers and plains.