Research On Mariculture Development Of China Under The View Of Economics

On the basis of researching on the history and current situation of our country's sea farming development, this article reveals mariculture's characters and its development regulations, and analyses the relationship between them with economic methods in aspects of farming, market, technology, and as such. By making economic and mathematical models such as the function of sea farming and the collective choice model of sea field, the article explains some facts in our country's sea farming such as fluctuation, low-productivity, and environment problems, gives some policy advices.This article summarizes that carrying capacity restrict is one of the most important reasons for the periodic development of China's mariculture. By analyzing the"Four Waves"in our country's mariculture development history, this article finds that there is another cycling fluctuation caused by carrying capacity restricts, besides which is caused by market (as in agriculture and all other long-term industries). It is closely connected with sea farming scale, density, and duration.Based on the research of carrying capacity according to the characters of mariculture ecological system, the article establishes the function of sea farming, develops the optimal production theory of sea farming. This theory subdivides the concept of carrying capacity into short-term carrying capacity, sustainable carrying capacity, and economic optimum carrying capacity. Finding that short-term carrying capacity is larger than sustainable carrying capacity and economic optimum carrying capacity, and the later may be equal to each other. To maximize personal profit, sea farmers will determine the largest farming scale according to economic optimum carrying capacity rather than sustainable carrying capacity, which can maximize social benefit. If sustainable carrying capacity is smaller than economic optimum carrying capacity, producers'rational actions may lead to over-farming. The function of sea farming shows that non-regulation to sea farming may result in over-farming and development fluctuation, and lower sea farming productivity.This article builds the collective choice model of sea field with game theory on the character of sea fields using style in our country's rural sea farming, finds that the externalities causing by sea water fluxion is a main reason which leads real farming scale beyond optimal scale. Because of the fluxion of sea water, the waste caused by mariculture can be transferred to neighbor farming units, which will make the determinations of different sea farmers in a same sea area affect each other. The article concludes that, in any situations, to every farmer in a sea area, the best strategy is enlarging farming scale. The fluxion of sea water causes externalities, externalities lead to over-farming.This article finds the possibility of disequilibrium in mariculture market, describing the process of"market failures"leaded by carrying capacity restrict, externalities, and market condition. The article concludes the supply function of mariculture according to the function of sea farming, does dynamic analysis to the supply and demand of mariculture market. When the equilibrium production represented by the junction of supply curve and demand curve is larger than sustainable carrying capacity, externalities and carrying capacity restrict will lead mariculture market to disequilibrium ---- the equilibrium price of mariculture product will be higher and higher, the equilibrium production of will be smaller and smaller, the two processes will strengthen each other. So,"market failures"caused by externalities may enhance over-farming and cycling fluctuation.This article summarizes characters of our country's mariculture technology evolution, analyzes the effects from carrying capacity restrict to technology evolution. There is a carrying capacity intensive technology evolution (k-type) in our country's sea farming development, besides general technology evolution (r-type) which exists in all industries. The k-type technology evolution is able to enlarge sustainable carrying capacity of sea farming field and enhance farming productivity by reducing carrying capacity restrict. The farming development histories of some Species such as shrimp and scallop reveal that the r-type technology evolution is the main technology evolution in the beginning of sea farming development of a species, and the k-type technology evolution becomes more and more important when farming scale is larger and large. Marginal profit analysis of sea farming technology evolution shows that the marginal profit of the r-type technology evolution is higher than the k-type technology evolution when farming scale is smaller than sustainable carrying capacity, but it will reduce quickly when farming scale grows larger than sustainable carrying capacity, while the marginal profit of the k-type technology evolution is growing. This article has a conclusion that technology evolution is one of the most important push powers in our country's sea farming development.At last, this article puts forward some administration regulation advices centered on environment. As sea farming can not realize sustainable and efficient development either by self regulation or by market regulation, so it is necessary to execute administration regulation by government. But the administration regulation of our country was almost centered on quantity quotas such as production growth and income growth in the past. This article summarizes the progress history of our country's sea farming administration regulation in last 30 years, introduces some administration regulations used in developed countries (Norway, EU, etc), concludes that our country's government should adopt sea farming administration regulation advices centered on environment which is aiming at restricting farming scale and preventing from over-farming.