The Bioeconomic Analysis of Bigeye Tuna (Thunnus obesus) in the Western and Central Pacific Ocean

• Main Authors: Yu-ching Chang, 張於靜
• Other Authors: Shan-non Chin
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/58475910290993721192

碩士 === 國立中山大學 === 經濟學研究所 === 100 === This study used the Gordon-Schaefer model which was extended to Open Access (OA) model and Present Value Maximization (MPV) model to discuss the equilibrium levels for bigeye tuna in the Western and Central Pacific Ocean by purse seine fishery data. I compared the catches and the biomass with the two model’s equilibrium value, and the result showed that the operating mode of bigeye tuna in the Western and Central Pacific Ocean tended to the MPV model, and the bigeye tuna resources were diminishing. In addition, the sensitivity analysis was used in order to understand the impact of various parameter changes on the two fisheries model’s equilibrium value. In the OA model, the change of the price, the cost per unit effort and the catch coefficient would have greater impact on the equilibrium biomass. In the MPV model, the equilibrium biomass was sensitive to the change of the environmental capacity. Finally, in order to understand whether the management of the Western and Central Pacific Commission (WCPFC) was effective, I used simulation analysis in accordance with the catches restriction and effort restriction management strategies. The result showed that the catches restriction strategy which WCPFC established was still not proper enough. It must cut a large number of catches immediately and continue for some time enough to make the resource recover. The effort restriction strategy could make good effect on the bigeye tuna resource recovery.