Construction of Water-saving Ecological Aquaculture Model in Ponds in North China

[Objectives] To explore the ecological aquaculture model in ponds in North China, several single techniques were assembled into the same culture system. [Methods] Three ponds were selected, the species and stocking rate were exactly the same, the water was not changed during the culture period, and the water loss due to evaporation and leakage was recovered. Since the middle of May, the hydrochemical indexes such as ammonia nitrogen, nitrite nitrogen, water temperature, dissolved oxygen and pH were monitored every 10 d. According to the monitoring results of ammonia nitrogen, carbon sources were added to the culture ponds to adjust the ratio of C to N, and carbon sources were added 9 times during the culture period. The stocking rate and yield per unit area were accurately measured at the beginning and end of the experiment, and no less than 30 fishes were randomly sampled to calculate the relevant growth indexes and feed coefficients. [Results] Except that the nonionic ammonia in pond 3# exceeded the standard by 10.3% on July 25, all other hydrochemical indexes met the Fisheries Water Quality Standard, and there was no significant difference in all hydrochemical indexes at the same time (P>0.05). The survival rate in 3 ponds was more than 95.0%, the average body weight of individuals out of the pond had no difference (P>0.05), and the feed coefficient was 1.41-1.43. There was no disease during the culture period, and the water was saved by 46.6% compared with the traditional culture model. [Conclusions] This study can provide a basis for the construction of a new model suitable for ecological aquaculture in ponds in North China.