碩士 / 國立高雄科技大學 / 漁業生產與管理系 / 107 / Small scale longline is the main fishery industry in Liuqiu Township, Pingtung. It usually carries out tuna fishing, but from March to May, many fishing boats change fishing gear, to catch dolphinfish in the western waters of North Pacific. In order to understand the catch characteristics of the Liuqiu dolphin fish longline in that sea area, this study choose two commercial fishing vessels to fill a total of 100 operation records. Data analysis showed that in terms of catch composition, the target species of dolphin fish accounted for 71.7%, other by catch species including striped marlin, black marlin, blue marlin, swordfish, sailfish, yellowfin tuna, other tuna, and other fishes. Liuqiu dolphin fish longline fishing gear has 6 hooks per basket, for each symmetrical hook CPUE by t-test results are not significantly different, so according to the depth of water from shallow and deep it could be divided intoⅠ,Ⅱ,Ⅲ Hook. The CPUE of each hook for dolphin fish showed significant differences thatⅠHook > II Hook > III Hook and CPUE has a tendency to decline with increasing depth. In terms of the average weight of the dolphin fish in each hook, it was shown that the average weight caught by the deeper hook was greater than that of the shallower hook. As for the comparison of the CPUE of dolphin fish with different operating conditions, it is shown that the CPUE is the highest at 2 o'clock, but there is no significant difference between the time of each throwing operation. When the weather is cloudy, the CPUE is higher than when it is sunny, and there is significant difference. In 1-5 sea state, the CPUE value increased with increasing sea state, but only 5 level of sea state has a very significant or extremely significant difference compared with 1, 2, 3 level of sea state. The CPUE of 340 baskets is higher and significantly different than that of the 460 baskets. The CPUE of surface water temperature has the highest at 26 ℃.
| Identifer | oai:union.ndltd.org:TW/107NKUS0451001 |
| Date | January 2019 |
| Creators | CHEN, SHAN-LI, 陳珊麗 |
| Contributors | LEE, LIANG-KANG, 李梁康 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 69 |
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