碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 106 / The Taiwanese seine fishery (also called the tiger nets) is one of the important fisheries in coastal waters off Taiwan. This fishery could lead to over-exploitation of fishery resources due to its high fishing effectiveness. To understand the characteristics of fishing activity and estimation of fishing effort (hours fished) for the Taiwanese seine fishery, the data from logbooks based on 6 trials (18 fishing sets) of 5 Taiwanese seine vessels groups (1 lamp boat and 1 seiner) that operate in waters off northeastern Taiwan were collected during 2014 to 2016. The vessel speed and trajectory at every 3-minute interval were recorded by voyage data recorder system (VDR) and then used to develop a filter model in this study. Based on the filter model, the fishing process could be separated into four fishing patterns: (i) cruising, (ii) light attracting, (iii) pursing and (iv) catching, accounting for the change of speed between two fishing patterns. We used the characteristics of speed and spatial distribution to predict the fishing set and further to validate with the information from logbooks. The 18 fishing sets were successfully identified and cross-checked with the records in the logbook according to the following criteria: during the fishing unit, the speed of lamp boat in light attracting was lower than 3 knots and seiner in pursing was higher than 3 knots. The average distance between lamp boat and seiner remain about 1.1 nautical miles (0.6 km) when pursing and the time taken to catch the fish ranges from 9 to 30 minutes. In summary, we suggest using the start of lamp boat when light attracting until the finish of seiner when pursing to define the fishing effort for the Taiwanese seine fishery, which was supported by the high-resolution data from VDR system as the results shown in this study.
| Identifer | oai:union.ndltd.org:TW/106NTOU5451007 |
| Date | January 2018 |
| Creators | LEE, YI-JOU, 李依柔 |
| Contributors | Liao, Cheng-Hsin, Su, Nan-Jay, 廖正信, 蘇楠傑 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 81 |
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