Dissertation/ Thesis
An Assessment of Indian Bigeye Tuna Stock by Equilibrium Production Model
| العنوان: | An Assessment of Indian Bigeye Tuna Stock by Equilibrium Production Model |
|---|---|
| Alternate Title: | 以平衡生產量模式評估印度洋大目鮪系群 |
| المؤلفون: | Hsiao-Chuan Chang, 張小娟 |
| Thesis Advisors: | Chien-Chung Hsu, 許建宗 |
| سنة النشر: | 1993 |
| المجموعة: | National Digital Library of Theses and Dissertations in Taiwan |
| الوصف: | 81 Annual catch of Indian bigeye tuna has been maintained in fluctuation between 40,000 and 50,000 tons since the early 1980's. However, the status of exploitation of the stock is still not clarified. In this thesis, I used the information of the historical catch and effort series to examine the exploitation of each fishing country and the availability of abundance index of the stock. Further, the Schaefer stock production model was applied to reveal the status of the Indian bigeye tuna stock, in order that the fishing effects and the exploitation rates could be detected for the managing policy- making. Data used in the analysis were the catch and effort series from Japanese, Korean and Taiwaneselongline fleets, and French and Spanish purse seine fleets. The catch per unit effort (CPUE) of purse seine fishery was not used as abundance index in the analysis, because the small fraction of bigeye tuna in the purse seine catch. The standardized longline CPUEs by GLM in compliance with the factors of fishing year, fishing season and fishing region, was adopted as abundance indices of the study stock. The comparison of standardized CPUEs by SNK- test showed that the Taiwanese standardized CPUE series was apparently different from the others (i.e., Japanese and Korean), and the comparison between Japanese and Korean series was not significant. As the result, the total effective effort was estimated as summing the effective efforts from Japanese, Korean fisheries directly, and Taiwanese fishery that the effort was reduced by the corresponding ratios of Taiwanese CPUE and combined Japanese and Korean CPUEs. Eventually the adjusted CPUE series excluding the CPUEs of 1977 and 1978, was applied to estimate MSY and fopt by Schaefer stock production model. Hence the MSY was estimated about 48,000 metric tons, which is equally likely equivalent to the present catch level. It is obvious to conclude that the Indian bigeye tuna is moderately exploited. |
| Original Identifier: | 081NTU00279007 |
| نوع الوثيقة: | 學位論文 ; thesis |
| وصف الملف: | 65 |
| الاتاحة: | http://ndltd.ncl.edu.tw/handle/60274602560748636751 |
| رقم الانضمام: | edsndl.TW.081NTU00279007 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
| الوصف غير متاح. |