The Study On Nitrogen And Phosphorus Budgets Of Circulation System Of Marine Fish

The incoming and outcoming of nitride and phosphor is considered as an effective method ofevaluating the importance of nitride and phosphor in acquaculture, the efficiency of transform andthe degree of the pollution in culture. Its main focus is the quantity relationship of incoming andoutcoming of nitride and phosphor of each ingredient, and the ecological factors and the differentmixed-culture model,such as temperature density and flux volume,which influence theincoming and outcoming of nitride and phosphor, thereby constituting the effective culture modeland increasing the transforming efficient of nitride and phosphor and the profit of ecologicalculture.Cycle marine fish system as study, it used self-made experimental apparatus circulatingwater fish, feeding and food utilization, nitrogen and phosphorus in a form in culture water and itschanges, the system of balance of nitrogen and phosphorus, nitrogen and phosphorus utilizationand environmental load of nitrogen and phosphorus was studied at a temperature of18℃、22℃、26℃and30℃, a density of10per square meter、20per square meter、30per square meter and40per square meter,a flow of2cycles per hour、4cycles per hour and6cycles per hour,at algaeof different fish and shellfish polyculture from Sep.2008to Apr.2009.The main content andconclusions of this study characterized are as follows:（1）Compared the growth rate of body weight at a temperature of18℃、22℃、26℃and30℃, a density of10per square meter、20per square meter、30per square meter and40persquare meter,a flow of2cycles per hour、4cycles per hour and6cycles per hour,at algae ofdifferent fish and shellfish polyculture, found that the growth rate of body weight and the dailyfeeding rate increased with increasing water temperature within the range from18℃to30℃.Thegrowth rate of body weight increased with the rise of stocking density within the range fromdensity of10per square meter to density of40per square meter, which was1.3times higher thanthat one at density of10per square meter. The growth rate of body weight increased of6cycles perhour was1.3times higher than the growth rate of body weight increased of the2cycles per hour. Mixotrophic culture of Fish-Shellfish-Algae of that was higher than mixotrophic culture of Fish-Shellfish.（2）Comparison of total ammonia nitrogen（TAN）、Nitrite、Nitrate and phosphate, theresults indicate that TAN and Nitrite didn’t out of range of piscine stand and they fluctuated in asmall range at the final stage of the culture season.Dissolution of Nitrogen in water did increasedwith increasing the filow,but it didn’t increased with increasing temperature and stockingdensity.Inorganic nitrogen and Phosphate of mixotrophic culture of Fish-Shellfish-Algae waslower than that of mixotrophic culture of Fish-Shellfish.（3）Through the analysis of Inputs of nitrogen in circulation system of marine fish,theresults showed that components of nitrogen and phosphorus input include grouper、ark shell、start adding water and into the experimental. Nitrogen and phosphorus input of grouper and arkshell accounted for total nitrogen and phosphorus inputs in the system for more than85%. Nitrogenand phosphorus inputs of grouper and ark shell accounted for95.94%~96.61%93.39%~97.74%phosphorus of total inputs within the range from18℃to30℃;that accounted for88.32%~96.65%nitrogen and88.24%~97.05%phosphorus of total inputs at four different stocking density;thataccounted for94.16%~96.01%nitrogen and94.27%~96.88%phosphorus of total inputs within therange from flow of2cycles per hour to flow of6cycles per hour;that accounted for96.07%nitrogen and97.05%phosphorus for mixotrophic culture of Fish-Shellfish; that accounted for93.26%nitrogen and93.34%phosphorus for mixotrophic culture of Fish-Shellfish-Algae.（4）The nitrogen and phosphorus outputs came from grouper、ark shell、particularorganic matter（POM）、dissolved in water and losses. Nitrogen and phosphorus output ofgrouper accounted for the largest proportion of total outputs.That accounted for71.21%~82.20%nitrogen and65.21%~79.10%phosphorus of total inputs within the range from18℃to30℃, theratio of26℃was significantly higher than other temperature group（P <0.05）; that accounted for65.04%~74.97%nitrogen and63.01%~74.13%phosphorus of total inputs at four differentstocking density, the ratio of density of30per square meter significantly higher than other densitygroup（P<0.05）; that accounted for66.61%~74.97%nitrogen and65.67%~74.13%phosphorusof total inputs within the range from flow of2cycles per hour to flow of6cycles per hour, the ratioof flow of4cycles per hour significantly higher than other flow group（P<0.05）; that accountedfor74.97%nitrogen and94.13%phosphorus for mixotrophic culture of Fish-Shellfish; thataccounted for70.18%nitrogen and68.70%phosphorus for mixotrophic culture of Fish-Shellfish-Algae.（5）Based on incoming and outcoming of nitride and phosphor, the balance formula of thesea-water recycle culture system is established in which it is found that the assimilation rate of nitride and phosphor in26℃group is40.87%and37.92%and significantly higher than othergroups(P<0.05), it indicates that it is most optimum temperature for the Epinephelus coioides in26℃; the assimilation rate of nitride and phosphor in30ind/m~2group is significantly higher thanother groups and the ratio of soluble nitride is6.58%(P<0.05), significantly lower than othergroups, it indicates that it is most optimum culture density for the Epinephelus coioides on thedensity condition of30ind·m-2; the assimilation rate of nitride and phosphor in4times/h group ishigher than other groups; the more the times of recycles, the higher outcoming rate there is in thegranule organic substance; there is no significant difference between fish&shellfish mixed-groupand fish&shellfish&algae mixed-group(P>0.05), but the loss rate of nitride of fish&shellfishmixed-group is2.3fold to the latter group.The budget equation of nitrogen and phosphorus for different temperature：18℃：100.00C_N=25.41G_N+15.74D_N+4.67O_N+54.18L_N100.00C_P=22.89G_P+38.06D_P+33.72O_P+5.33L_P22℃：100.00C_N=16.99G_N+6.47D_N+3.53O_N+73.01L_N100.00C_P=15.78G_P+32.90D_P+26.01O_P+25.81L_P26℃：100.00C_N=40.87G_N+6.58D_N+5.97O_N+46.58L_N100.00C_P=37.92G_P+17.22D_P+30.74O_P+14.12L_P30℃：100.00C_N=30.44G_N+5.53D_N+4.13O_N+59.90L_N100.00C_P=28.32G_P+8.38D_P+56.43O_P+6.88L_PThe budget equation of nitrogen and phosphorus for different stocking density：10per square meter：100.00C_N=33.26G_N+12.83D_N+20.89O_N+33.02L_N100.00C_P=30.23G_P+30.32D_P+33.76O_P+5.64L_P20per square meter：100.00C_N=31.56G_N+38.04D_N+21.70O_N+8.70L_N100.00C_P=29.21G_P+13.37D_P+30.20O_P+28.22L_P30per square meter：100.00C_N=40.87G_N+6.58D_N+5.97O_N+46.58L_N100.00C_P=37.92G_P+17.22D_P+30.74O_P+14.12L_P40per square meter：100.00C_N=29.29G_N+26.04D_N+34.78O_N+10.09L_N100.00C_P=27.08G_P+9.49D_P+45.84O_P+17.59L_PThe budget equation of nitrogen and phosphorus for different flow：2cycles per hour：100.00C_N=16.21G_N+4.28D_N+6.05O_N+73.46L_N100.00C_P=14.69G_P+33.81D_P+23.81O_P+27.69L_P4cycles per hour：100.00C_N=40.87G_N+6.58D_N+5.97O_N+46.58L_N100.00C_P=37.92G_P+17.22D_P+30.74O_P+14.12L_P 6cycles per hour：100.00C_N=26.28G_N+12.22D_N+56.35O_N+5.15L_N100.00C_P=24.04G_P+7.21D_P+63.51O_P+5.24L_PThe budget equation of nitrogen and phosphorus for mixotrophic culture of Fish-Shellfish andmixotrophic culture of Fish-Shellfish-Algae：Fish-Shellf：100.00C_N=40.87G_N+6.58D_N+5.97O_N+46.18L_N100.00C_P=37.92G_P+17.22D_P+30.74O_P+14.12L_PFish-Shellfish-Algae：100.00C_N=36.49G_N+4.49D_N+38.86O_N+0.08AN+20.08L_N100.00C_P=34.75G_P+7.34D_P+36.68O_P+21.23L_PAccording to the results demonstrated before, we consider that the optimum condition is26℃of water temperature,30ind/m~2of culture density and4cycles/h and the optimum culture model isfish&shellfish&algae mixed-group.