農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

2005年3 ~ 7月間，利用溫深鹽儀 (CTD) 計測台灣東北部海域 (24.5° N ~ 27.0° N, 121.0° E ~ 123.5° E) 36個測站的水文基礎資料，並配合魚探機同步收錄魚群影像資料，期間共計進行四航次的調查研究。經由各月別水平及垂直的溫鹽分布圖顯示，當黑潮流經臺灣東北部海域時，由於受到東海大陸棚海底陡升之影響，形成地形性湧升冷渦。該冷渦終年持續存在，強度則隨位置與深度而略有不同。經由溫深鹽儀測得海洋表水溫之分布圖，可發現除了3月份的航次，因冷渦沉潛於水深40 ~ 60 m處，不易由海水表層觀測到中心位置外，其於各航次均可由表水溫分布狀態辨認其位置。經由本研究調查結果推測，距該冷渦中心10 ~ 20浬，水深介於100 ~ 200 m處，似乎為鯖鰺魚群出沒之海域。

To determine the characteristics of upwelling, located at 24.5°~27°N and 121°~123.5°E, and its effect on the distribution of mackerel and scad , 138 survey stations from four cruises in March, April, June, and July 2005 were sampled in the waters off northeastern Taiwan. Depth, seawater temperature, and salinity were collected by (CTD). Based on the data analyzed, the upwelling of a cold eddy was found to exist on all four cruises. The strongest cold eddy existed at depth of 40~60 m in the waters off northeastern Taiwan. The best habitat area for mackerel and scad was evaluated at depths of 100~200 m at 16-32 km from the center of the cold eddy position. The location of the cold eddy can be used as a reference when searching for mackerel and scad schools.