碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 102 / Abstract
The present study aimed to investigate time-space allocation of torch-lighted fisheries in the water off Penghu Islands and southwestern Taiwan. Fishing logbook and VDR (voyage data recorder) data of 19 torch-lighted fishing vessels were routinely obtained from Jan 2010 to Dec 2010. These data were further analyzed using state-space model to investigate dynamic characteristics of these fishing vessels, including speed and turning angles. In addition, habitat distributions of major fish species caught by these fishing vessels were also examined.
According to the state-space model, VDR data of fishing vessels were classified into 4 states as follow: leaving from port, fishing operation, transiting between fishing grounds, and returning to port. For the state of leaving from port, vessel speed was approximately 6-12 knots and frequency of 0° turning angle was approximately 45-80%.
For the state of fishing operation, vessel speed was approximately 1-3 knots and frequency of 0° turning angle was approximately 30-70%. For the state of transiting between fishing grounds, vessel speed was approximately 3-4 knots and frequency of 0° turning angle was approximately 35-50%. For the state of returning to port, vessel speed was approximately 2-9 knots and frequency of 0° turning angle was approximately 40-80%.
Additionally, time-space allocation of torch-lighted fishing vessels was found to be varied seasonally. For example, fishing operations mainly occurred in the water 2-38 nautical miles off coast and lasted for 1-6 hours during winter. The vessels left ports between 14:00 and 16:00, which was likely duo to the earlier sunset during winter. On the other hand, fishing operations mainly occurred in the water 0.3-2.14 nautical miles off coast and lasted for 40 mins-15 hours during summer. The vessels returned to ports between 3:00 and 5:00, which was likely duo to the earlier sunrise in the winter. Furthermore, the time-space allocation of torch-lighted fisheries was also found to be affected by lunar phases and tides.
| Identifer | oai:union.ndltd.org:TW/102NTOU5451037 |
| Date | January 2014 |
| Creators | Wang, Wan-Ting, 王琬婷 |
| Contributors | Liao, Cheng-Hsin, 廖正信 |
| 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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