碩士 / 國立海洋大學 / 漁業科學研究所 / 83 / Tuna purse seine fishery, which mainly catches skipjack and yellowfin tunas, is a highly efficient, labor-saving and mobile fishing method. Currently, in western Pacific ocean, fishing war among tuna purse seine ships from Taiwan, Japan, korea and US is becoming more and more competitive. To increase our competitiveness, skills for selecting fishing ground have to be enhanced. Therefore, I have conducted a through study of Pacific fish distribution and its relationship with water temperature. The major findings of my study are summarized as follows:
1). Fish school type: Yellowfin tunas are mostly in unassociated school, and skipjack tunas are often in timber unassociated school. The high catch volume of timber unassociated school The high catch volume of timber unassociated school fishes could be the result of counter current in north Equator brings down the timber of Indonesia area to Micronesia area.
2). Monthly catch distribution: Between June and November, it is in east-west course. Between December and May, it is in south-north course. The distribution mode is related to the currents in the Equator area.
3). Relationship of fish distribution and temperature of surface water: Short warm pool and south-north fish distribution from December to June; long warm pool and east-west fish distribution from June; long warm pool and east-west fish distribution from June to November.
4). Center of monthly fishing grounds: The center is in the closed area between 1° N and 4° N., 145° E and 152° E. From January to June, the center grandually shifts fron 2° N to the north. Starting from July. the center move to the east.
5).Temperature of surface water:Best temperature is between 28.3° C and 29.8℃
6).The catches of SPC area have changed in the month before EI nino happened. Cpue is worse when the negative deviation rate of surface water temperature is larger. CPUE is better when the surface water temperature is close to nomal temperatuer.
7). Compare catches and CPUE in 150° E logitude, between 5° S and 15° N, Fish distribution is centered between 0° N and 10° N, highest between2° N and 5° N. This could be the result of shallow thermocline between 0° N and 5° N.
| Identifer | oai:union.ndltd.org:TW/083NTOU3451003 |
| Date | January 1995 |
| Creators | 黃逸宜 |
| Contributors | 陳俊德 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 73 |
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