Influence of largemouth bass Micropterus salmoides farming in floating troughs on water quality in a closed lake
LIU Jianyu1, REN Wenqiang2, WANG Henglin1, ZHANG Li1, ZHOU Yanfeng3*, XU Hangtao4, YOU Yang1,3*
1.Wuxi Fishery College, Nanjing Agricultural University, Wuxi 214081, China；2.National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai; 3.Key Laboratory of Freshwater Fisheries and Utilization of Germplasm Resources,Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi; 4.Wuxi Liushui Fish Intelligent Technology Limited Company, Wuxi
Abstract: The floating water tank is a new fish farming facility in lakes in recent years, in order to evaluate the influences of the floating water tank(25.0 m×5.0 m×2.5 m)during the farming activities on the small lake’s internal water environment which is intercepted by a bay, this study selected six representative sites inside and outside the water tank in the small lake and to monitored the space and time differences in water quality and sediment in environment of largemouth bass Micropterussalmoides culture during three growth stages(fingerlings, juveniles, and adults)in June, August and October in 2018.Using three kinds of water quality models including Vollenweider model, Dillio model, and Hetian model at various seasons, the influences of farming in the floating water tank on the water environment were evaluated.The results showed that water quality was within Class II water or Class III water inside and outside of the tank during the culture.It was found that the interception device of the floating water tank showed the most obvious effect on the elimination of CODMn, and the elimination effect on TP was inferior to CODMn, while the interception effect on TN and NH3-N was worse than that of TP and CODMn.The water environment capacity of TP was 56.93 kg/a, 60.12 kg/a, and -28.01 kg/a in three periods, respectively.The findings indicated that the presence of the water tank led to the decline of water environment capacity and the deposition of nitrogen and phosphorus in the sediment downstream of the water tank, with little effect of the water tank on the water quality level in the lake.
2020, Vol. 35 
