BREEDING PROCAMBARUS CLARKII SEEDLINGS IN GREENHOUSE ON NUTRIENTS IN AQUACULTURE WATER

The rapid increase of nutrients and the decline of aquaculture water quality often occur in the process of aquaculture. It is necessary to carry out systematic research on the effect of severe human and biological disturbance on the water quality of aquaculture water by using greenhouse to breed Procambarus clarkii seedlings. To explore the water quality, this study measured the dynamic changes of water quality and nutrients in surface sediment of the high-density breeding of crayfish seedlings in greenhouse in winter. The results showed that the DO and WT of the water body varied from 5.75 to 6.33 mg/L and 12.6℃—22.9℃, respectively, and the water temperature was 5—10℃ higher than the external water temperature in the same period. The contents of TN, TP and COD were 2.091—2.688, 0.196—0.480 and 42.400—53.200 mg/L in the overlying water, respectively, which were relatively higher due to feeding and shrimp activities. The contents of TN, TP and organic matter in surface sediment ranged from 1032 to 1279, 623 to 1004 and 12.00 to 14.28 mg/kg, with an increase of 24%, 23% and 41%, respectively. Due to the high turbidity of the water body and the unknown number of parent shrimp in the water body, it is impossible to determine whether all the feed was consumed by shrimp and the rapid increased nutrients in the aquaculture water due to the more feed. The high nutrient content brings new requirements for the treatment of the aquaculture tail water in the later stage.