碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 101 / The purpose of this thesis is to explore spatial and temporal characteristics of crab trap fishing activity in the water off northern Taiwan. The catch data from logbooks and track data from VDRs (Voyage Data Recorder) of 12 fishing boats were routinely collected from Nov 2011 to December 2012 and further integrated using GIS (Geographic Information System) approaches. According to the average speed of fishing vessels, fishing operations were classified into three categories: 8.04±1.43 knot for cursing between harbor and fishing grounds, 2.78±1.17 knot for releasing crab traps, 7.44±1.64 knot for collecting crab traps and sifting between fishing grounds. The main fishing grounds, ranged from 120.55-121.77 °E and 25.00-27.35 °N, were on the continental shelf of East China Sea with depths of 50-200 m. Three crab species, Charybdis feriatus, C. natator, Portunus sanguinolentus, accounted for the majority of catches. Monthly CPUE (catch per unit effort) of C. feriatus and C. natator both rose to the highest level in November (8.29 &; 2.06 kg/hr) while that of P. sanguinolentus rose to the highest level in September (4.31 kg/hr). In contrast, monthly CPUE of C. feriatus dropped to the lowest level in January (1.27 kg/hr) while that of C. natator and Portunus sanguinolentus dropped to the lowest level in March (0.07 kg/ &; 0.0.32kg/hr), respectively. Additionally, gravity center of monthly CPUE was also found to be varied with seasons and crab species. Taken together, it is effective and feasible to monitor spatial and temporal characteristics of crab trap fishing activity in the waters off northern Taiwan by integrating catch information from logbooks with more precise and unbiased track information from VDR.
| Identifer | oai:union.ndltd.org:TW/101NTOU5451038 |
| Date | January 2013 |
| Creators | Hau-Yu Chen, 陳皜宇 |
| Contributors | Chang-Hsin Loao, Hsiang-Wen Huang, 廖正信, 黃向文 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 104 |
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