碩士 / 國立臺灣海洋大學 / 水產養殖學系 / 99 / This study was to evaluate three historic habitats of two creek watersheds through the survivals, growth and recruitment of in situ investigation on the population dynamics of the released Formosan Landlocked salmon (Oncorhynchus masou formosanus) from 2009 to 2011. A total of 900 fish had been released to Lo-Ye-Wei, Gon-gamin(Su-Jie-Lan upstream branch I) and Gon-bkuli (Su-Jie-Lan upstream branch II) from June 2009 to May 2011.
The adult mortality and larval recruitment rate in Lo-Ye-Wei creek were 31% and 530% in 2010, while these two values were 47.8% and 368% in 2011. In Su-Jie-Lan creek, the respective adult mortality and larval recruitment rate of the overall two upstream branches were 71.9%, 62.5% in 2010 and 45.5%, 0% in 2011. The population density was 0.01fish/m2 in Gon-gamin and 0.03fish/m2 in Gon-bkuli and 0.06fish/m2 in Lo-Ye-Wei.
The values of specific growth rate of adult fish ranged between -0.13 to 0.15 among the three habitats across spring to winter seasons indicated that adult fish growth was limited by the environment factors especially a possible insufficient amount of food availability by the feeding ground. The spring-summer SGR values of the juveniles in Lo-Ye-Wei was between 0.70 to 0.95 better than the autumn-winter SGR values (0.36-0.43). The SGR values of juvenile fish in Gon-gamin was significantly better during autumn-winter season (0.91) than that during spring-summer season (0.52). There were no significant difference between spring-summer SGR value (0.27-0.65) and those of autumn-winter season value (0.59-0.64) in Gon-bkuli.
The size of the population(436) in the habitat of Lo-Ye-Wei creek was 12 times the size of the total sum of the two habitats of the upstream branches of Su-Jie-Lan and the biomass of the former one (25.2kg) was 14 times that of the later one. Moreover the concrete population age structure of Lo-Ye-Wei habitat suggested a successful satellite population would soon reach a balance state in the near future. Prohibition of the agricultural activities as well as the increatment of plant coverage to increase the food availability in order to expand the feeding ground area of the downstream area of Lo-Ye-Wei creek was strongly recommended.
| Identifer | oai:union.ndltd.org:TW/099NTOU5086024 |
| Date | January 2011 |
| Creators | Bwo-Siou Jheng, 鄭博修 |
| Contributors | Dr. Yii-Shing Hung, 黃沂訓 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 84 |
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