Research On The Evaluation Model Of Technical Performance And Operating Cost Of Seawater Industrialized Circulating Aquaculture System

The new seawater industrialized recirculating aquaculture mode has the characteristics of water purification and reuse.It also has the advantages of small space occupancy rate,highly controllable aquaculture environment,high aquaculture yield and good production quality.However,with the development of seawater industrialized recirculating aquaculture,the research on its technical performance and operation cost has not received much attention.Through the combing of relevant references at home and abroad,it is found that there are few studies on the technical performance and operation cost evaluation of seawater industrialized recirculating aquaculture system,and there is no analysis and research on the combination of recirculating aquaculture system and actual aquaculture activities.In this study,by collecting the performance and cost data of the marine recirculating aquaculture system during the breeding of half-smooth tongue sole,the water treatment effect and breeding effect of the recirculating aquaculture system were analyzed.The relationship between the cost items was studied by multiple linear regression,and the influencing factors affecting the technical performance and operation cost were explored.Finally,the evaluation model of the seawater industrial recirculating aquaculture system was constructed by using the expert scoring method and the analytic hierarchy process.The data of this study were derived from the Cynoglossus semilaevis cultured by a seawater factory recirculating aquaculture enterprise in Binhai New Area of Tianjin.The main research methods include:(1)Literature research method.The development history,technical performance and technical level of recirculating aquaculture system at home and abroad were studied.(2)Field research method.In-depth investigation of different seawater recirculating aquaculture enterprises on the recirculating aquaculture system and data collection.(3)Data preprocessing.The initial data are sorted out,and the missing data are interpolated by linear regression interpolation method and adjacent point mean interpolation method.(4)Multiple linear regression.In practice,the influencing factors of production and breeding are studied and analyzed with each cost item,and the causal relationship between the observed values of the influencing factors and each cost item is observed from a micro perspective.(5)Analytic hierarchy process(AHP):Based on a large number of studies on the technical performance and operation cost of seawater industrialized recirculating aquaculture,the evaluation model of technical performance and operation cost of seawater industrialized recirculating aquaculture was constructed by AHP.The operation effect of the recirculating aquaculture system was analyzed by the aquaculture data of half-smooth tongue sole collected from the enterprise.The results showed that the half-smooth tongue sole was cultured in the recirculating aquaculture system for 407days.The initial average body weight of the fry was 5 g,and the final average body weight of the adult fish was 1079 g.The final breeding density was 20～25 kg/m~2,and the survival rate was 29.1%.The breeding effect was good.The average degradation rate of ammonia nitrogen was 64%,the average degradation rate of nitrite was 58%,the killing rate of Vibrio and bacteria was 99%,the p H value was maintained at 7～8.5,and the salinity was maintained at 18～35 mg/L.The water treatment effect of the circulating water system was good.From the perspective of multiple linear regression of cost items,a multiple linear regression model was established for the cost items of fixed asset depreciation,employee wages,feed costs,drug costs,hydropower and liquid oxygen costs,and amortization costs,fish body specifications,and fish tails.Among them,R~2performed better and MSE was lower.From the perspective of individual influencing factors,all passed the significance test,and the increase and decrease of fish body specifications and fish tails basically showed positive changes in each cost item.The weight values of equipment performance and technical level,water treatment effect,breeding cost,management cost and breeding effect were calculated by AHP analysis method to be 0.391,0.267,0.150,0.120 and 0.072,respectively.The higher weight is equipment performance and technical level,followed by water treatment effect.The two indicators of breeding cost and management cost also occupy an important position,which are mainly affected by the energy consumption of the circulating water system and the cost expenditure during the breeding period.The index with the lowest weight is the breeding effect,not that the breeding effect is not important,but that the breeding effect has a lower impact than other indicators.