東太平洋熱帶區(ETP)圍網漁業作業方式可分為海豚群與非海豚群。海豚群捕到的黃鰭鮪較多，但有海豚混獲的問題；反之，非海豚群捕到的鰹鮪較多，但卻有鮪魚丟棄的問題。因此，漁民作業方式的選擇對ETP圍網漁業有很大影響性。若漁民多採用海豚群，則能捕抓到較多且較具經濟價值的黃鰭鮪，但卻會造成大量海豚死亡。反之，若漁民多採用非海豚群，雖不會傷害到海豚，但該作業方式捕到的鮪魚體型小，丟棄率相當高，這會影響到漁民整體的利潤。本研究想探討在同時面對海豚群會有海豚混獲與非海豚群會有鮪魚丟棄的兩難下，漁民該如何選擇作業方式。此外，管理者是否可以透過禁止海豚群或者禁止非海豚群，使漁民利潤極大，且又能維持鮪魚與海豚的生態平衡。

In the Eastern Tropical Pacific (ETP), the operation mode of purse-seine fishing can be divided into dolphin sets and non-dolphin sets. Dolphin sets can catch more yellowfin tuna, but cause a lot of dolphin deaths. On the contrary, non-dolphin sets can catch more skipjack tuna, but discard a lot of tuna. Therefore, the choice of the operation mode to the ETP purse-seine fishery is very influential. If the fishermen use more dolphin sets, they are able to catch high quantity and more valuable yellowfin tuna. Conversely, if the fishermen use more non-dolphin sets, they will not hurt dolphins. But the tuna fish caught by this operation mode is smaller in size and the discarding rate is extremely high which will affect the overall profits of the fishermen. The research will investigate how the fishermen make the choice of the operation mode in the dilemma between dolphin sets which cause dolphins-bycatch and non-dolphin sets which result in tuna-discarding, In addition, if managers can ban dolphin sets or non-dolphin sets to maximize the profit of the fishermen and maintain the ecological balance between tuna and dolphins.

第一章 緒論 1
第一節 研究背景與動機 1
第二節 研究方法與目的 3
第三節 研究架構 5
第二章 文獻回顧 6
第一節 東太平洋熱帶區(ETP)圍網漁業概況 6
第二節 海豚混獲與丟棄成本的相關文獻 9
第三章 理論模型 13
第一節 模型基本假設 13
第二節 開放式漁場模型 15
第三節 現值極大化漁場模型 18
第四章 實證結果與分析 24
第一節 東太平洋熱帶區(ETP)圍網漁業資料來源 24
第二節 在同時採用海豚群與非海豚群、只採用海豚群(禁止非海豚群)以及只採用非海豚群(禁止海豚群)情況下的均衡解比較............28
第三節 東太平洋熱帶區(ETP)圍網漁業實際數據與均衡值的比較 34
第四節 敏感度分析 40
第五章 結論與建議 65
第一節 結論 65
第二節 建議 66
參考文獻 68
附錄 71

於仁汾、張水鍇、王世斌，1999。「世界鰹鮪圍網漁業簡介」，中華民國對外漁業合作發展協會。
Conrad, J. M. and C. W. Clark, 1987. Natural Resource Economics, New York : Combridge University Press.
Clark, C. W., 1976. Mathematical Bioeconomics: The Optimal Management of Renewable Resource, New York : John Wiley & Sons.
Conrad, J. M. and R. Adu-Asamoah, 1986. “Single and Multispecies Systems: The Case of Tuna in the Eastern Tropical Atlantic,” Journal of Environmental Economics and Management. 13 : 50-68.
Chin, Shan-non., 1993. “Fishery Management：Management of Tuna Harvest with Dolphin Mortality in the Eastern Tropical Pacific,” Ph. D. Dissertation, Cornell University.
Cappell, R., 2001. Economic Aspects of Discarding : UK Case Study-Discarding by North Sea Whitefish Trawlers. UK : Nautilus Consultants Ltd.
Edwards, E. F., 1992. “Energetics of Associated Tunas and Dolphins in the Eastern Tropical Pacific Ocean : A Basis for the Bond,” Fishery Bulletin. 90 : 678-690.
Edwards, E. F., 2007. “Fishery Effects on Dolphins Targeted by Tuna Purse-Seiners in the Eastern Tropical Pacific Ocean,” International Journal of Comparative Psychology . 20 : 217-227.
Enriquez-Andrade, R. R. and J. G. Vaca-Rodriguez, 2004. “Evaluating Ecological Tradeoffs in Fisheries Management: A Study Case for the Yellowfin Tuna Fishery in the Eastern Pacific Ocean,” Ecological Economics. 48(3) : 303-315.
Gerrodette, T. and J. Forcada, 2005. “Non-Recovery of two Spotted and Spinner Dolphin Populations in the Eastern Tropical Pacific Ocean,” Marine Ecology Progress Series. 291 : 1-21.
Graham, M., 1935. “Modern Theory of Exploiting a Fishery and Application to North
Sea Trawling,” Journal of Marine Science. 10(3) : 264-274.
Hall, M. A., 1998. “An Ecological View of the Tuna-Dolphin Problem : Impacts and Trade-Offs,” Reviews in Fish Biology and Fisheries. 8 : 1-34.
Hall, M. A., D. L. Alverson, and K. I. Metuzals, 2002. “By-Catch : Problems and Solutions,” Marine Pollution Bulletin. 41: 204-219.
Hoagland, P. and D. Jin, 1997. “A Model of Bycatch Involving a Passive Use Stock,” Marine Resource Economics. 12 : 11-28.
Herrick, S. F., B. Rader, and D. Squires, 1997. “Access Fees and Economic Benefits in the Western Pacific United States Purse Seine Tuna Fishery,” Marine Policy. 21(1) : 83-96.
Haraden, J., S. F. Herrick, D. Squires, and C. A. Tisdell, 2004. “Economic Benefits of Dolphins in the United States Eastern Tropical Pacific Purse-Seine Tuna Industry,” Environmental & Resource Economics. 28 : 451-468.
Inter-American Tropical Tuna Commission, 2000-2008. Annual Report of the Inter-American Tropical Tuna Commission. La Jolla, California : Inter-American Tropical Tuna Commission.
Inter-American Tropical Tuna Commission, 2003-2008. Fishery Status Report. No.1-6 : Tunas and Billfishes in the Eastern Pacific Ocean in 2002-2007. La Jolla, California : Inter-American Tropical Tuna Commission.
Inter-American Tropical Tuna Commission, 2000-2008. Stock Assessment Report of Yellowfin. No.1-9 : Status of Yellowfin Tuna in the Eastern Pacific Ocean in 1999-2007 and Outlook for the Future.
Inter-American Tropical Tuna Commission, 2000-2008. Stock Assessment Report of Skipjack. No.1-9 : Status of Skipjack Tuna in the Eastern Pacific Ocean in 1999-2007 and Outlook for the Future.
Joseph, J., 1994. “The Tuna-Dolphin Controversy in the Eastern Pacific Ocean : Biological, Economic, and Political Impacts,” Ocean Development and International Law. 25 : 1-30.
Josupeit, H., 2007. Developments of Tuna Prices and Future Trends. Rome : FAO.
Punsly, R. G., P. K.Tomlinson, and A. J. Mullen, 1994. “Potential Tuna Catches in the Eastern Pacific Ocean from Schools not Associated with Dolphins,” Fishery Bulletin. 92 : 132-143.
Perrin, W. F., R. R. Warner, C. H. Fiscus, and D. B. Holts, 1973. “Stomach Contents of Porpoise and Yellowfin Tuna in Mixed-Species Aggregations,” Fishery Bulletin. 71(4) : 1077-1092.
Pascoe, S. and D. Greboval, 2003. “Measuring Capacity in Fisheries,” FAO Fisheries Technical Paper. No. 445.
Schäfer, M. B., 1954. “Some Aspects of the Dynamics of Populations Important to the Management of Commercial Marine Fisheries,” Bull. Inter-Amer. Tropical Tuna Comm. 1 : 25-56.
Vaca-Rodriguez, J. G. and R. R. Enriquez-Andrade, 2006. “Analysis of the Eastern Pacific Yellowfin Tuna Fishery Based on Multiple Management Objectives,” Ecological Modelling. 191 : 275-290.