Abstract This study is based on the theory of biology and economy to establish the open access model, dynamic optimization model and static optimization of fishery mathematical models, to discuss the problem of fishery management. To be aimed at getting the equilibrium of resource stock and effort, research data are mainly analyzed by comparative statues. In so doing, the amount of grey mullet, collect and analyze the estimation of exogenous variable. Then, we can use Mathematica program to calculate the equilibrium value resource stock and the effort, and do the sensitivity analysis by standing on the change of estimation of exogenous variable. The result of analysis is as follow: These three fishery mathematical models¡¦ resource stock and effort are consistency. In another view of CPUE, it is not obvious of the economic effect of open access model. We must strengthen the management in policy of fishing for grey mullet, to let the fisherman earn the highest economic benefits. Keyword: open access model static optimization model. dynamic optimization model.

The fishery of the shrimp Acetes intermedius in the southwestern coast of Taiwan has long history , and it is the food of many species of fishes and large-scale shrimps . Shrimp Acetes has not only fallen on dead ears , but also been ignored its importantce of ecologyical status in the southwestern coast by the academia because of less harvest and output value in the past . It then comes into operation the management of catch , leading the price going up and output value increasing rapidly when the establishment of TungKang producer organization of the shrimp Acetes intrmedius in 1994 , and it also becomes the important seasonal fishery . According to as was mentioned above , the study is based on the theory of biology and economy to put out the open access model , static optimization model and dynamic optimization of fishery mathematical models , and further discuss the problem of fishery management. In connection with getting the equilibrium of resource stock and effort , research data from the substitution of real data are mainly analyzed by compareative statues on exogenous variable .By means of understanding the sensitivity of variation on endogenous variable depending on exogenous variable , we can provide the member of TungKang producer organization of the shrimp Acetes intrmedius with the control on harvest and preservation of stock . The study can get the fact that the management of TungKang producer organization of the shrimp Acetes intrmedius has the notion of sustainable administration by the deriveation of theoretical model and the simulate analysis of historyical data. I hope the management of TungKang producer organization of the shrimp Acetes intrmedius can be popularized.

In this study, the fundamental model of fish dynamic model- Gordon Schaefer Model is used to discuss the equilibrium levels for the Pacific Bluefin Tuna fishery of open access and dynamic optimization, and then to do the sensitivity analysis. By comparing the historical record of catch data with the equilibrium values of open access and dynamic optimization, we could know that the fish stocks and harvests of Pacific Bluefin Tuna are not in the condition of dynamic optimization. In order to ensure the sustainable development of Pacific Bluefin Tuna fishery, we have to take effective measures to preserve and manage the Pacific Bluefin Tuna resources. Finally, this study simulates and analyses the various management scenarios of the Pacific Bluefin Tuna fishery. The results of simulative analysis reveal that the optimal management of the Pacific Bluefin Tuna fishery would imply significant reallocation of the fishing gear shares. Furthermore, the net present value could increase substantially by reallocating the fishing gear shares.

This thesis is based on Gordon-Schaefer model, and assesses Argentine shortfin squid¡¦s stock by using the data of Southwest Atlantic from FAO between 1983 and 2009. First, estimate the equilibrium level of the open-access fishery and dynamic optimization fishery and compare to each other. Then estimate annual Argentine shortfin squid¡¦s stock size, comparing the stock size with the equilibrium level of the two fishery models. The result is that Argentine shortfin squid¡¦s stock size has no crisis of extinction now in Southwest Atlantic. In addition, simulate Argentine shortfin squid¡¦s stock size under management and no management status in the future. The result is that it will make the Argentine shortfin squid sustainable development under dynamic optimization fishery, and this fishery model will be a good management. Finally, this thesis based on the catch of Southwest Atlantic Argentine shortfin squid, which we figure out the fluctuation of catch by literatures, and do the sensitivity analysis.

Tong-Kong sakura shrimp is one of important fisheries in southwest coast. Tong-Kong sakura shrimp, blue fin tuna and mullet roe are called Three Treasures of Tong-Kong . It brings significant economic benefits for local residents. This research is based on Gordon-Schaefer Model theory that combines with fishery catch statistics and operational cost data. Also, we use these data to discuss open-access fishing ground and dynamically optimal fishing ground of balance status under equilibrium level. Next step is to do stimulation analysis that based on annual fishery catch statistics of sakura shrimp. After stimulation, we can make comparisons of equilibrium values of these two fishing grounds. From analysing fishery catch statistics and fishing resource we may know that it can shows that the management of sakura shrimp tends to dynamically optimal fishing ground, and also can state that the management mechanism of sakura shrimp is an ideal of sustainable management. Then, through the example, we can understand how each variation influences fishing resources and fishing effort of these two fishing grounds. Finally, we simulate fishing resources model of two fishing grounds to show the result. If we don¡¦t manage fishery of sakura shrimp well and keep uncontrolled fishing, not only the fishing ground will become an open-access fishery, but also fishing resources will become extinct. However, once we can manage fishing ground efficiently, it will become a dynamically optimal fishing ground and the fishery of sakura shrimp will develop sustainably.

The study is based on Gordon-Schaefer model, using statistic data from Western and Central Pacific Fishery Commission to estimate the resource stock of Albacore between 1960 and 2009. Compare the equilibrium levels of open access model and present value maximization model with the real data, and the result shows that the real stock is close to the equilibrium of present value maximization model. The thesis uses sensitivity analysis to understand the impact of the changed parameters on stock and effort, and by using real examples to understand the impact of the changed situation on stock and effort. Finally, by simulating the stock of open access fishery and present value maximization fishery and government management nowadays fishery. The result shows the stock of government management fishery is higher than the stock of the present value maximization fishery, and the stock both are closed. The management is conservative and effective, hence the management will make the profit maximize and the resource continue forever to develop.

This study used the Gordon-Schaefer model to discuss the equilibrium levels for bigeye tuna in the Western and Central Pacific of open access and present value maximization. And then to compare the catches and the stocks on the two model¡¦s equilibrium value, the result shows the management of bigeye tuna in the Western and Central Pacific tend to present value maximization model. Following that, this paper did sensitivity analysis to understand the impact of the changed parameters on stock size and effort. Finally, using simulation analysis on open access model and present value maximization model. In open access model, the result shows that resources will face extinction crisis if the fishery is not controlled well. In the present value maximization model, the bigeye tuna would be sustainable management. This result is valuable for the fishery management authorities to maintain the development of fishery and cherishing ocean resources at the same time.

Abstract This study used the Gordon-Schaefer model to do resource economic analysis on the South Pacific albacore fishery in 1967-2007 . Evaluated the equilibrium standard of open access model and present value maximization model, and then compared them with the real data. The results indicates that the fishing yield, resource stock, effort and catch-per-unit-effort of south Pacific albacore is close to the equilibrium level of present value maximization model after year 2002, which means the South Pacific albacore fishing is under appropriate development. Following that, this paper did sensitivity analysis to understand the impact of the changed parameters on stock size and effort. Finally, using the simulation analysis on open access model and present value maximization model. In open access model, the result shows that resources will face extinction crisis if the fishery is not controlled well. In present value maximization model, the albacore fishery would sustainable management. This result is valuable for the fishery management authorities to maintain the development of fishery and cherishing ocean resources at the same time.

Sergestid Shrimp contains rich nutrition, regards as a high-class aquatic product in Japan. The management of the catch has come into operation, and it¡¦s led the price raising and the output value increasing rapidly when the establishment of TungKung producer organization of the Sergestid Shrimp in 1993 and it also has become the important seasonal fishery in the southwestern coast of Taiwan. This study is based on the fundamental model of fish dynamic- Gordon Schaefer Model, to discuss the equilibrium values for the optimal conduction of open access and dynamic optimization, and to do the comparative statics analysis. By applying the data provided by Fisheries Research Institute, the evaluation of the variation are under both conductions were available, and in additions, the sensitivity analysis had been done by assuming all bio-economics parameters varied within a reasonable range. The study can figure out the fact that the management of TungKang producer organization of the Sergestid Shrimp with the notion of the sustainable administration by the derivation of theoretical model and the simulate analysis of historical data, and the conclusions of analysis are consistency. Furthermore, the study discusses the fishery management policies of TungKung Sergestid Shrimp. I hope the management policies of TungKung producer organization of the Sergestid Shrimp could be popularized in the related industry.