Water Quality And Regulation In A Half Cycle Model Of Shrimp-fish

This study builds a fish pond shrimp-half cycle model, the system consists of filter feeding fish pond and low salinity intensive shrimp pond, at the same time fish pond provides water for the shrimp pond, and improving the water quality by disinfection, stocking filter feeding fish, regular delivery of micro ecological preparation synthetic regulation technology. The study provides the basic data for the optimization of the model, to physical-chemical factors, bacteria, algae of the fish and shrimp ponds for monitoring, the main results as follows:1. Comprehensive control on the fish pond water physicochemical biological indicators of the impact study shows, integrated control significantly reduced fish vibrio quantity, fell by45.64%on average; vibrio to total heterotrophic bacteria proportion of average dropped53.37%, showing that integrated control can effectively reduced the number of harmful bacteria in the integrated water. At the same time, algal density of fish ponds algal density and biomass increased by59.38%on average, algal biomass increase by58.6%on average. In addition, the comprehensive regulation improved DO of the water and alleviated pH of the water.2. On the use of fish pond water as water source (experimental pond) water physical and chemical biological indicator monitoring results show that: in the whole cycle, in the shrimp pond vibrio is at a low content, changing smoothly, average value is0.18×103CFU/ml, using the river as a water source contrast pond vibrio will be sudden outbreak in the late. At the same time, The PhytoPlankton were identified belonging to6Phyla54genera and126species in experiment pond; and were identified belonging to6Phyla47genera and87species in contrast pond. In the late of the experiment pond the species number is higher than at the same period of the comparison pond; in the comparison pond it appears cyanobacteria bloom in the later (chroococcoid density account for the total density97.7%); Shannon-Wiener diversity index in the experimental pond changes more smoothly than in the comparison pond, algal phase more stability. In addition, in the morning DO of the experimental pond was significantly higher than of the control pond (P<0.05). Finally, survival rate of the experimental pond was65.5%, it was higher than the control pond about37.5%; yield of the experimental pond is4515kg/hm2, it was higher than of the control pond about17.1%.3. Supplementary water from the fish pond, DO of the shrimp pond water increased by 7.70%, transparency increased by32.41%, pH dropped by4.32%, but in the morning pH significantly reduced. Nitrous acid nitrogen declined by21.13%; algae density increased by29.16%, algae biomass increased by44.81%, the species number of algae increased by68.39%.4. When the pH of the fish ponds lower than the shrimp ponds at the same time of the experiments, pH of the fish ponds is closer to the optimal pH (7.5-8.5). Nitrous acid nitrogen of the fish pond water Oi.s significantly lower than of the shrimp pond; biomass and density of algae in the fish pond is more stability than in the shrimp pond; in the fish pond Chlorophyta and Bacillariophyta entire breeding process, but in th shrimp pond green algae and diatom is mainly in the late; Shannon-Wiener diversity index in the fish pond is higher than in shrimp pond at the same period, community complex, the stability of water quality. Vibrios quantity in shrimp pond is lower and change more smoothly than in fish pond.