| The farming method of“greenhouse with deep well seawater”in turbot industry started in China in 1992.Today turbot breeding has become popular in China coastal provinces,north to Liaoning and south to Fujian,especially in the waters of the Yellow Sea and the Bohai Sea.In 2018,Shandong and Liaoning were the top two in turbot aquaculture output with 41,700 tons,about 83.73%of the total in China.Our survey data reveal that industrialized running water aquaculture(RWA)accounts for more than95%aquatic water of the total industry,while the recirculating aquaculture system(RAS)accounts less than 5%.The differences between RAS and RWA are clarified in two aspects.The first aspect is pollution emission.Based on the method of material balance calculation,0.136 kg nitrogen and 0.018 kg phosphorus per kilogram is emitted in turbot aquaculture.From the assumption of compound feed,41,700 tons of turbot aquaculture may result in the emission of 5660 tons'nitrogen and 749 tons'phosphorus.In fact,now the amounts of chilled fish feed are around 3.5 times the compound feed,the former feed causes more serious‘secondary pollution'than the latters.In February2019,having been ratified by the State Council,the Ministry of Agriculture and Rural Affairs,jointly with other 9 departments such as the Ministry of Ecology and Environment,the Ministry of Natural Resources,the National Development and Reform Commission etc.,issued“Suggestions for Promoting the Development of the Green Aquaculture Industry”with the purpose of tackling the heavy pollution from the chilled fish feed.This document states clearly that compound feed should take the place of chilled fish feed and chilled fish should be restricted strictly in direct feeding.Now,it is impossible to achieve the goal of‘zero emission'with the present equipment for circulating water aquaculture,but low emissions of contaminants can be realized in RAS.The second aspect is resources consumption.The mode of RWA for turbot industry costs too much water resources.Water resource consumption of turbot running water aquaculture in Shandong is 30 m~3/kg and Liaoning 17 m~3/kg respectively.The total water consumption for turbot industry was up to 8.29×10~8 cubic meters in Shandong and Liaoning province in 2018.While,0.6 m~3 of water is enough for one kilogram of turbot industry on RAS mode.The total water consumption would be 2.52×10~7 m~3 on the condition of RAS.Water resource consumption of RWA is 33 times of RAS.With the intensifying competition and the expansion of farming scale,the industrialized RWA has caused serious negative impact on the circumstances:(1)Resources of inefficient used and over-exploited.The uncontrolled exploitation of groundwater has resulted in the drop of the phreatic line and the serious sink in topical areas;the utilization rate of land and water is rather low.(2)The low standard of controlling the serious pollution emissions.Without a unified planning and a standard curbing the emission,the intensive farming of turbot has made nitrogen and phosphorus pollution exceed the standard in some waters,thus the eutrophication is more and more serious.Turbot aquaculture now is endangered by the pollution from aquaculture itself.The serious economic losses and the rising social costs are crying for an urgent solution to the sustainable development of turbot farming.Turbot of running water aquaculture is characterized by extensive operation of linear development:high input,undue consumption,heavy pollution and inordinate emission.It is quiet worrisome in the view of its long-term development and this research is based on the subject.The dissertation consists of eight chapters,and the contents of each are as follows:Chapter ?:Introduction to the background,the content,the method,my ideas,the technical routes and the innovation of the research.Chapter ?:Document review and the evaluation of the relevant research literatures from home and abroad.Chapter ?:Definitions of the key concepts and illustration of the theoretical foundation and the economic analysis mode of this study.Chapter ?:Status quo of turbot farming industry in China:advantages and shortcomings.Chapter ?:The fifth chapter focuses on the complete cost in the industrialized RWA mode of turbot culture and the negative impacts on the circumstances,thus the insufficient cost pricing in traditional accounting system is revealed.The primary products are related to the undue consumption of natural resources and the destruction of environment,so the environmental cost per unit of output value will be higher than that of other high-tech products.Traditionally,the cost of aquatic products ignored the environmental factors in cost accounting system.The prices of aquatic products have not included all the factors:costs are underestimated while benefits are overestimated.It is not good for resources conservation and environmental protection.The environmental costs should be taken into consideration in the accounting system.Study on the efficiency of industrialized RWA mode of turbo farming with the data envelopment analysis(DEA)method.The aim is to determine the effective input and output of each production unit so as to find the main reasons for the low production efficiency and then to improve the farming practice with the efficient use of resources.Chapter ?:Research on the sustainable development of the farming mode of turbot in China.Evaluation has been made through the ecological footprint index method providing data support for aquaculture transformation.Study on the strategic decision on the aquiculture investment of turbot.Dynamic comparison has been made between RWA and RAS through the real option pricing theory for the decision-makers'reference in the face of many uncertainties.Chapter ?:The main conclusion and transformation mechanism.The main conclusions of the former 8 chapters are summarized and the transformation mechanism of turbot farming industry from RWA to RAS.Chapter ?:Summary and outlook.To summary current Chinese aquaculture development,and put forward the perspectives of subsequent scientific research ideas.Apart from the relevant literature review,the theoretical foundation and the economic mode to solve the problem are set up in the first four chapters.Furthermore,the key problems in the research are raised through the analysis of the current situation of turbot culture in this part.The study of the totally cost and efficiency problem shows the shotcomings of running water aquaculture and the necessary of transformation from RWA to RAS.Instrontion RWA is unfavorable to sustainable development,and then uses the ecological footprint index method to show RWA has high environment pressure and it belongs to unsustainable development.Turbot water aquaculture transformation is imperative.Then use the real option pricing theory to verify the above research conclusion,the conclusion is consistent,circulating water aquaculture is the main development direction of the future breeding.The main research conclusion of this article is as follows:So the real costs of aquatic products have been underestimated while the profits overestimated.In the present price system featured by‘free resources,cheap raw materials and costly goods',it is very difficult to promote the economical utilization of the fishery resources.The environmental costs vary in accordance with the different natural conditions in turbot culture.For example,groundwater is priced at 0.08RMB/m~3 in Shandong province while in Liaoning 0.11 RMB/m~3.This is caused by the different scarcity of natural resources in different places,and this phenomenon conforms to the dual value theory of natural resources.The traditional accounting result shows that turbot aquaculture cost in Shandong is slightly lower than that in Liaoning,but complete cost accounting shows that the real cost of turbot farming in Shandong province is 39.43 RMB/kg while 37.08 RMB/kg in Liaoning province.It is quite clear that the complete cost of turbot aquaculture in Liaoning province is lower than that in Shandong.The insufficiency of the traditional cost accounting system leads to cost underestimation,profits inflation,serious resources abuse and heavy pollution.The optimal allocation of resources comes from the rational pricing of the products,thus the external costs should be taken into consideration.It is of great significance for reducing environmental pollution and retarding ecological destruction.The efficiency of industrialized RWA mode is studied in Chapter VI.The inefficient production of turbot aquaculture is revealed through the negative externality analysis.As the farming scale expands,the rigidity of land and the scarcity of various resources will gradually become more prominent.Our research shows that only 27%of the decision-making units in the turbot aquaculture are in the frontier of efficiency,and70%of the farmers need to improve their production efficiency.Even though some farmers have a large scale in production,there is a big gap from economies of scale.Among the 92 valid samples,the largest aquaculture area is 10,000 square meters while the smallest one is only 200 square meters.The average area is 4116 square meters and the effective decision-making unit is 3,636 square meters.The results show that it is possible to cut down the input of land resources in the RWA mode and the production efficiency of each aquaculture scale has a large room for improvement.The production elements such as fish feed;fry and the fixed assets can be largely reduced through urgent technological improvement.We found that changing the input of fish feed and fry has a relatively large effect on the improvement of the production efficiency.The increase in the cost of fish feed not only restricts the profits of aquaculture(over 50%of the production cost is fish feed.The data comes from‘Research report on the changes in production elements and economic benefits of the flounder industry,2015').Meanwhile,excessive investment(in such as fish feed)will also aggravate pollution and have a negative effect on the environment.These problems can be solved by improving the efficiency of comprehensive aquaculture so as to achieve the coordinated development of aquaculture in economy,resources and ecological balance.The study of the complete cost and efficiency aims to probe into the causes of the problems in the RWA mode and argues that it is not good for the sustainable development of the industry.The decline of technology and efficiency in the aquaculture makes it necessary for transformation so as to be competitive.Chapter ? conducts a quantitative study for the transformation with the ecological footprint index method to evaluate the sustainability of turbot aquaculture in RWA and RAS.The per capita ecological footprint of the turbot aquaculture in RWA is0.0348 ghm~2 while that in RAS is 0.1331ghm~2,just 13%of the former mode.Its pressure on the environment is relatively small and it is a weak sustainable development mode.In contrast,the RWA's low conversion rate of fish feed,heavy secondary pollution,extravagant use of water resources with low efficiency have exerted great pressure on the environment,and the ecological footprint index is negative,exceeding the ecological capacity.Fish feed and energy contribute a lot to the ecological footprint.RAS can effectively reduce the feed coefficient and the economic cost of aquaculture,then lower the ecological footprint.Thus the resources consumption can be reduced and the economic and ecological benefits can be raised.Transforming the growth mode of aquaculture is the only way for its sustainable development in China.Although the water treatment equipment is still not perfect in our country and it cannot achieve'zero emission',the RAS mode is still one of the most promising farming modes in the future.It will play a significant role in the economic and ecological development.Chapter ? is about the simulation of turbot culture mode on the basis of the real option pricing theory.The aquaculture enterprises or farmers must face the uncertainties from the changes in price,production cost and the future policy.Only the adoption of the higher-tech production methods can avoid the adverse impacts from these uncertainties in the future.It is a wise choice for the aquaculture enterprises and farmers to be alert to the uncertain factors and to transform to a higher-tech production mode.Our research shows that in the same uncertain environment,the benefits from RAS are higher than that of RWA.The main reason is that the water in RAS can be regenerated within the threshold range to form a virtuous circle of ecological chain.Therefore,RAS is the main direction of the development of future aquaculture industry.The study of complete cost and efficiency aims to point out the defects in RWA mode and the need for transformation.With the ecological footprint index method,the qualitative indication shows that the RWA mode is not good for its sustainable development and the transformation of turbot aquaculture is imperative.Based on the real option pricing theory,the numerical simulation indicates that the results are consistent with the current situation.All our endeavors are meant to show that RWS is the main direction of future development in aquaculture.We hope our study will provide a theoretical basis for promoting the transformation of aquaculture modes.To make full use of various forms of transformation mechanism to promote turbot breeding mode transformation in China.Chinese turbot breeding mode to environmentally friendly water transformation mechanism can be divided into:the market mechanism,the information transmission mechanism,the mechanism of ecological compensation mechanism,agglomeration development,green financing mechanism,insurance mechanism,the mechanism of taxes and fees and so on seven aspects.Local companies or aquaculture producers should make full use of market and the transformation of administrative means to promote the breeding pattern,in order to ensure the sustainable development of turbot breeding.In this paper,the innovation points are as follows:(1)Enrich and expand the turbot industry research in the field of economy.Aquaculture economic research object of study is relatively concentrated,mainly divided into shrimp,shellfish,algae and fish,fish mainly include salmon,salmon,tilapia,large yellow croaker,turbot industry economic research are relatively few.In recent years,with the development of turbot aquaculture,gradually abundant research achievements.Research contents have turbot industry trade development strategy research,market research,consumer behavior research,farming income,breeding efficiency,such as industry sustainability research rarely involved.(2)The rich resources and expand the aquaculture research framework for pricing.Resource pricing research mainly concentrated in the coal,oil,natural gas,minerals and other natural resources,rarely involves the breeding value of water resources research,water resources as an important factors of production necessary in aquaculture cost accounting system,so as to promote the effective utilization of resources.(3)Enrich and expand the literature in the field of small scale ecological footprint.Fishery ecological footprint prophase mainly concentrated in the large scale field(country,area,district,etc.)of natural waters aquaculture and fisheries research.Putting forward along with the composition of the ecological footprint method and other methods,the ecological footprint research to the small scale development.In this paper,the composition of the ecological footprint method and the method of ecological footprint index turbot cultured analysis of sustainable development,enrich the researches on the ecological footprint small scale. |
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