碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 107 / The dolphinfish (Coryphaena hippurus) is one of the most important economic species for Taiwanese offshore and coastal fishery and most catches were caught in the eastern waters of Taiwan. Therefore, dolphinfish is an important target species for fishery in the eastern waters of Taiwan. The data used in the study were historical total catches, length-frequency and daily auction data of dolphinfish from Yilan, Haulien, and Taitung. In this study, the population status of dolphinfish in the eastern off Taiwan was evaluated using age-structured production model (ASPM). The relative abundance index was based on the catch per unit effort (CPUE) standardized using general linear model (GLM) based on daily auction data. The base-case results of ASPM indicated that the catches were mainly consisted of fishes with 1-year-old. The spawning stock biomass decreased gradually with increase of catch, but the current fishing mortality was still below the maximum sustainable yield (MSY) level and the spawning stock biomass was slightly higher than the MSY level. The result of the sensitivity analysis indicated that the results of assessment model are sensitive to the values of natural mortality and steepness. The current fishing mortality was below the MSY level in most of cases, but the spawning stock biomass was close to or slightly higher than the MSY level. Based on the results of this study, there is a higher probability that the dolphinfish in the eastern waters of Taiwan was moderately exploited currently, but there is also a risk that the spawning stock biomass may not maintain at the MSY levels. Therefore, in order to maintain the sustainability of this stock, it is necessary to continuously evaluate and monitor the stock dynamics of the resource and exploitation for the fishery.
| Identifer | oai:union.ndltd.org:TW/107NTOU5451019 |
| Date | January 2019 |
| Creators | Lin, Yu-Yong, 林鈺詠 |
| Contributors | Wang, Sheng-Ping, 王勝平 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 67 |
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