Study On The Aerations And Submerged Plants Combined Remediation Of The Pond Water Environment Of Chinese Carb (Eriocheir Sinens)

Under the guidance of building up scientific development concept, developing the type of resources saving and friendly environment aquaculture, this study established a model of ecological restoration in Eriocheir sinens ponds aquaculture, which consisted of a improved aeration system, kinds of plants. In crab ponds two kinds of aeration system were compared, the effects of micropore oxygen aeration and common aeration on the water quality and soil enzymes activity were studied. A better ecological restoration model was established in crab pond culture system.The effects of two kinds of aeration were detected and compared, the results showed that:Under the condition of high temperature in summer> the difference in temperature of water between the surface and the bottom could be effectively reduced down, especially to the temperature of the bottom water, the micropore oxygen aeration could oxygenate the water quickly and effectively, had the5times dissolved oxygen increase velocity than common aeration. The aquaculture water with the micropore pulp aeration was about70%ofNO2-N,22.9%of NH3-N and20%of CODMn lower than the related indexes with the common aeration.The concentrations of total nitrogen(TN), total phosphorus(TP) and ammonia (NH3-N) is significantly lower with the aeration than the others (p<0.05) in June to September, and in each index’s concentration is the aeration<the mechanical<the control. The study also reveales that the concentrations of TN,TP and NH3-N can be effectively controlled by aeration. with the quality improved, the pond cultural water meet the respective discharge standard.The effects of different aerations on urease, invertase, phosphatase,and catalase activities is studied, and the relationship between the soil enzymes activity and nutrients factors tested is discussed by correlation analysis. The results showed that:(1) the seasonal variation variation curves of the soil phosphatase and urease activities were all "single peak curves",while the soil catalase activity increase in whole, and the soil invertas activity change a lot between months.(2) Obvious response was showed of soil enzymes activity to the two aerations, both two aerations can increase the four soil enzymes activities, and while the micropore aeration significantly increased the four soil enzymes activities (p<0.05).(3)The correlations between the soil enzymes activities and soil nutrients factors of two aerations were different, there was significant positive correlations between the soil Phospatase activity and organic mater (O.M), Total nitrogen (TN),alkaline hydrolytic nitrogen and available P (p<0.05). The soil urease activity had a sinificant positive correlations with nitrogen (TN) and alkaline hydrolytic nitrogen, aslo sinificant positive correlation between the soil catalase activities with TP and available P (p<0.05), while there were no significant correlations between the soil invertase activities and the nutrients factors.Three kinds of ecosystems which compounded with different submerged plants and crab (Eriocheir sinensis) co-cultured were made, and the effects of the three ecosystems on the water quality index and immune parameters in different tissues (gonad, muscle and liver) were detected in the culture period. The results showed:ecosystems compounded with kinds of submerged plants and crab can significantly improve the water quality, while, the one compounded with various submerged plants have a significantly better results on the water improvement than the one with mono-plant.The activities of immune parameters such as SOD, CAT, T-AOC, AKP, ACP, UL and Na+/K+-ATPase are highest in gonads of crabs which were cultured in the three ecosystems. There was difference among the immune parameters activities in different tissues and crabs in the different ecosystems.) The activities of Ca2+/Mg2+-ATPase were highest in muscles of crabs which were cultured in two ecosystems of submerged plant elodea and potamogeton maackianus, and multiple grass, but was highest in gonads of crabs which cultured in the ecosystems of submerged plant elodea.