碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 93 / During 2001 ~ 2004, we collected length data of spotted mackerel (Scomber australasicus) from purse seiners on Nanfanao fishing market. The length frequency data obtained were then analyzed by FiSAT (ICLARM) to estimate parameters of von Bertalanffy equation, which gives an asymptotic length = 43.02 (cm)、growth parameter K=0.79 (year )and to=-0.21. The result that L∞ to diminish, K become high, and the spotted mackerel have miniaturization phenomenon to show. The exploitation is estimated as about 0.7, so there is phenomenon of overexploitation on the ultilization of the spotted mackerel’s resource. Monthly age compositions calculated by length frequency data were submitted to Virtual Population Analysis. The result suggests that recruitment fluctuated greatly during 1982-2004. The phenomenon may link to the occurrences of ENSO events. During the period, 7 El Niño events and 4 La Niña events occurred, respectively. The recruitments were at low level stage during El Niño period, but at high level stage during La Niña period.
Key words: Scomber australasicus、ENSO、Virtual Population Analysis
| Identifer | oai:union.ndltd.org:TW/093NTOU5451046 |
| Date | January 2005 |
| Creators | Ke-Yeng Chen, 陳科仰 |
| Contributors | Kuo-Tien Lee, 李國添 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 54 |
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