Optimized Construction Of Engineering Pond And Production Study Of Shrimp At Zero Water Exchange

In order to explore the development of green and healthy model of shrimp,the paper chooses Shigongliao village shrimp farms,and aquatic biology company shrimp farms separately to carry out the optimized construction of zero water exchange system for different ponds and production trial of Litopenaeus vannamei based on biofloc technology in zero water exchange systems.The experimental design and main results are as follows:(1)Engineering optimization of small cement pond system:reforming small ponds,optimizing oxygenation system,water circulation system and water treatment system.The specific optimized construction content includes in this trial:three small cement ponds are connected with each other to form a closed cascaded ponds system,and four simple internal recycling aquaculture systems are build.Each group is equipped with a 1.5 kw circulating water pump,a 120 L biofloc sediment bucket,and each cement pond is equipped with a venturi ejector in four corners,each jet is connected to a circulating water pipe and a circulating water pump.(2)Engineering optimization of culture pond system of higher-place:oxygen enhancement system,water circulation system and water treatment system are optimized by reforming the pond.The specific optimization construction includes the transformation of a pond into two raceway-typed ponds.Each system is equipped with two 7.5 kw circulating water pumps,a 120 L biofloc sediment bucket.Each pond is equipped with 71 venturi ejector and is evenly distributed in the raceway-typed ponds.And each venturi ejector is connected to a circulating water pipe and a circulating water pump.(3)Taking advantage of optimized small cement pond to carry out zero water exchange culture experiment of Litopenaeus vannamei:the stocking density of shrimp was 690 ind/m~3,and the culture period was 91 days.Biofloc technology was used to control the water quality of pond systems,and no water was exchanged during the whole culture period.The cultured shrimps grew well.The average weight of them was 14.50 g/ind.The average survival rate was 83.9%.The average yield was 8.39 kg/m~3,and the feed coefficient was 1.25.Seven weeks after the start of the trial,the bioflocs volume in the culture water was 18.2~30.4mL/L,and the concentrations of ammonia nitrogen and nitrite nitrogen were kept below 0.70mg/L.The average water volume used for production 1 kg shrimps was 120 L.(4)Taking advantage of optimized culture pond system of higher-place to carry out zero water exchange culture experiment:the stocking density of shrimp was 1,251 ind/m~3.The culture period was 49 days,which does not complete the shrimp culture.However,during the operation of the optimized culture system,good water quality control effect,zero water exchange throughout the culture process,and target oxygen increasing efficiency have been achieved.