碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 107 / 英文摘要
Blue marlin (Makaira nigricans) play an important ecological and economic role in pelagic ecosystems, exerting top down control on their prey in waters off eastern Taiwan. Rich food resources were found in the Kuroshio Current, but little is know about the feeding ecology of the area. This study aims to understand the trophic level of the blue marlin and the relationship to ecology of Kuroshio Current. Results from the index of relative importance (IRI) showed variation among season. The most common prey species in spring were Auxis rochei rochei and Exocoetidae (IRI = 1465 and 828). The most important prey species in summer were Trichiuridae and Cephalopoda (IRI = 1913 and 1078). Carangidae and Scombridae were major prey species in autumn (IRI = 2087 and 1538), while Cephalopoda and Katsuwonus pelamis were found commonly in winter (IRI = 1465 and 828). However, the most important prey species were Cephalopoda and Carangidae for class 1 (100-150 cm), but for Cephalopoda and Auxis rochei rochei in length class 2 (IRI = 887 and 623). In length class 3 (larger than 200 cm), the most important prey species were Cephalopoda and Trichiuridae (IRI = 1735 and 821). The proportion of prey intake by blue marlin changed significantly with sizes. Stable isotope analysis showed that δ15N values were between 8.7~14.4‰, and δ13C values between -15.7~-20.7‰. Results indicated a relationship between trophic level and length class. Pelagic preys were major food resources for blue marlin, but with high diversity in their diet. Blue marlin were demonstrated to be an opportunistic pelagic predators, with diet varying among seasons and sizes. Results from this study suggested that as a high level trophic level species, blue marlin play an important role in marine food webs.
| Identifer | oai:union.ndltd.org:TW/107NTOU5451010 |
| Date | January 2019 |
| Creators | Chang, Chi-Hsuan, 張綦璿 |
| Contributors | Su, Nan-Jay, Chiang, Wei-Chuan, 蘇楠傑, 江偉全 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 62 |
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