碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 97 / From the long-term (1996-2011) observations on wintertime sea surface temperature (SST) fields of satellite-derived data, wind speed and coastal fishery production around Penghu, the exceptional cold water intrusion into the southern Taiwan Strait (TS) were noted in the La Nina winter, 2008 and 2011. Comparing the SST and wind speed during El Niño/La Niña events, we found that SST was warmer in the El Niño winters than in the La Niña winters, while wind speed was more intensive in the La Niña winters than in the El Niño winters. In the La Nina winter of 2008 and 2011, the strong and continuous northeasterly wind caused by a La Niña event drove the cold Mainland China Costal Current more southward allowing it to penetrate into the southern TS north of the Chang-Yuen Ridge, and a portion of this current intruded eastward to south of the Penghu Islands. These two events resulted in a SST decline of 11.6 and 7.4℃, respectively. The former also significantly damaged marine life, causing the death of more than 73 tons of fishes at Penghu Islands, but not for the latter.
Comparing variations of the first quarterly catches and species compositions in 2008 with long-term averages from 1996 to 2011, we found about 45-80% decreases in the catches of pole and lines boots, misc. fish long line, and gill net fisheries, which was dominated by non-migratory species and more than long-term averages 280% increase in the set net fishery, which was mainly composed of migratory species. In other words, the exceptional cold water instrusion impact on the benthic/resident fishes, but not for pelagic fishes of coastal fishery.
| Identifer | oai:union.ndltd.org:TW/097NTOU5451051 |
| Date | January 2011 |
| Creators | Yi-Chou Yang, 楊易洲 |
| Contributors | Ming-An Lee, 李明安 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 74 |
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