碩士 / 國立中山大學 / 海洋環境及工程學系研究所 / 105 / Fisheries rank the top position in Taitung since there are many oceanic migrating fishes attached to Kuroshio current to spawn closed to the coastal in Eastern Taiwan. Also, set net fishing is popular in Taitung. There are two primary factors of catch from set net, the sea-bottom terrain and characteristics of ocean current.
In order to examine the relationship between the current and the catch from set net, It has been investigated and analyzed by TOROS with offshore surface current data from set net located in Yilan Nan’ao in 2012 to 2015. The study also discussed the movement of Kuroshio along the shoreline of Yilan Nan’ao and its correlation with yield in set net. In addition to understand the current characteristics near set net sites, the bottom-mounted multi-layer ADCP were used to measure the flow velocity through the opening of set nets on two sites which were located in both northern and southern of Yilan Nan’ao. After the analyzing the current characteristics from those set-net, the relationship between its catch and current can be investigated.
The result of from this study indicated as follows: First, according to the analysis of TOROS, Kuroshio mainstream is found about 40 km off to the coastlines of Yilan Nan’ao and Hualien Hoping in Eastern Taiwan, the width about 90 km, the average of its surface velocity is 58cm/sec. Second, the possibility of switching in flow direction to west of Kuroshio will increase if the average offshore surface velocity decreases in Nan’ao and Hoping. Third. There were more Auxis rochei from set net when the monthly surface velocity of Kuroshio decreased in Nan’ao and Hoping. Fourth, the increasing of the yield of Auxis rochei is not correlated with the changing flow direction of Kuroshio. Final, there is no much difference of environmental factors between two set-net for Auxis rochei, while the possibility of increasing yield from southern set net has been investigated after 4 days of the decreasing of its daily mean velocity.
| Identifer | oai:union.ndltd.org:TW/105NSYS5282022 |
| Date | January 2017 |
| Creators | Yen-Hsun Chen, 陳彥勳 |
| Contributors | Shiahn-Wern Shyue, 薛憲文 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 83 |
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