Investigation And Research On Physical And Chemical Environment And Fishery Resources Of Sailimu Lake

In recent years,China's national economy has developed rapidly year after year,and the people's living standards have improved steadily.The requirements of Chinese residents for a balanced diet are also increasing,especially for cold water fish rich in nutrients.As the largest alpine cold water lake in Xinjiang,Sayram Lake,located in the alpine basin in the northwest of Xinjiang Uygur Autonomous Region of China,has vast water area,and the water entering the lake is mainly ice melt water,mountain precipitation and spring water.The water quality is not polluted.It is one of the best choices for stocking cold water fish.Through the investigation and experiment on the hydration environment,physical environment,plankton,benthos,microorganisms,fishery resources,fish characteristics and fishing methods of Sayram Lake,this paper understands the current situation of physical and chemical environment and biological resources in the lake area,analyzes the impact of stocking cold water fish in Sayram Lake on the environment,and puts forward a more reasonable scheme of stocking cold water fish.The main investigation and experimental results are as follows:1.The four measured water quality analysis data from August 2020 and January2021 show that Sayram Lake is not polluted by the external environment,and the water quality is generally in good condition,which meets the class I standard of the national surface water environmental quality classification standard(gb3838-88).The water quality is good.Except that the total hardness and sulfate are class III standards,other projects meet the class I water standard.2.The distribution of microorganisms in the lake area is relatively uniform,with relatively few species and quantities,which is in line with the basic characteristics of plateau cold water lake.3.Compared with the survey results in the lake area in 2010,the number of phytoplankton increased,but the biomass decreased.From the perspective of species composition and dominant species,the community structure of phytoplankton changed;The number of zooplankton has doubled,but the biomass has not changed.The stocking of cold water fish in the lake area has basically no impact on plankton,and the ecological balance is maintained well.4.The physical environment of Sayram Lake is mainly affected by the lake climate.The flow field in the lake is mainly affected by the wind speed on the lake surface and the topography at the bottom of the lake,and the mixing depth on the east bank is less than that on the West Bank.It is helpful to maintain water quality and environment.At the same time,the ice closure period of Saihu lake is long,from late December to early May of the next year.During the ice melting period,the vertical mixing of lake water can promote the improvement of bottom nutrients,and play a positive role in maintaining the primary productivity of the lake area and improving the water quality environment.The distribution of water temperature and salinity and seasonal variation had no effect on the stocking of cold water fish.5.According to the acoustic method and traditional net sampling method,the existing fish resources in the reservoir area are between 250 tons and 400 tons.Compared with the existing fishing volume,the estimated output is lower than the actual output.The main reason is limited by the selective factors of survey sampling and survey vessels.In terms of acoustic evaluation,it is necessary to further study the target strength of fish,improve the limitation of selectivity of nets,and improve the level of investigation and resource evaluation.6.Under natural conditions,Coregonus peled and concave eye white salmon grow faster,and the age of 2-3 can reach more than 500 g.7.Sayram Lake now carries out live fish fishing in the form of fixed net,but the fishing efficiency is low,and there is a lack of fish monitoring equipment in the net box,poor slow culture conditions and low controllability.It is necessary to further improve the fishing methods,increase the non feeding cage slow breeding facilities,implement the light bait slow breeding,and the sound domestication of Coregonus peled and concave white salmon.