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

秋刀魚是西北太平洋海域重要的漁業資源之一，也是我國遠洋棒受網作業漁船之主要漁獲對象魚種，有必要進一步瞭解秋刀魚的漁場動態變化。本研究處理分析2006–2008年秋刀魚漁獲統計資料，顯示其平均單位努力漁獲量（CPUE）為18.5公噸/日/艘，作業海域集中於北緯38–49度、東經143–162度，其作業重心有明顯的月別變化，且主要漁期為6至12月。另外，處理分析2006–2008年MODIS衛星海面水溫資料，以直方圖邊緣偵測法，分析水溫鋒面分布位置，探討秋刀魚漁獲位置與水溫鋒面之相關性。結果顯示，6-8月份水溫鋒面少，秋刀魚CPUE低，9-12月水溫鋒面增加，其CPUE升高，且漁獲位置愈靠近水溫鋒面，其CPUE有愈高的現象。此外，本研究利用衛星海面高度距平值（SSHA）及地轉流分布，篩選出SSHA值小於-25cm之封閉海域為冷水渦，SSHA值大於15cm之封閉海域為暖水渦。結果顯示，黑潮續流與親潮交匯區是冷、暖水渦密集形成海域，而親潮區的暖水渦分布，則會影響秋刀魚的漁獲高低。6-8月份暖水渦數量較少，其對應的秋刀魚單位努力漁獲量也較低，僅約9.7公噸/日/艘。但是9-12月份之暖水渦數量增加約兩倍，其單位努力漁獲量也上升為19.5公噸/日/艘。另外，也發現秋刀魚單位努力漁獲量與秋刀魚漁獲位置至暖水渦的最短距離，兩者間直線迴歸呈現顯著的負相關（R2=0.35）。

This study had processed the 2006-2008 logbook data of Pacific saury fishery, which had an average catch per unit effort (CPUE) of 18.5 tons/day/boat and its fishing grounds concentrated into 38-49 oN latitude and 143-162 oE longitude. Its major fishing season is from September to December and there is an evident monthly variation of fishing gravity. We used the 2006-2008 MODIS satellite-derived sea surface temperature (SST) data to extract the frontal areas by histogram-based edge detection algorithm. The results indicated that the higher CPUEs had a shorter distance to SST fronts. Additionally, the satellite-derived sea surface height anomaly (SSHA) and the geostrophic current had been used to define that its SSHA value is less than -25cm of the enclosed area for the cold eddy and the SSHA is greater than 15cm for the warm eddy. The results showed that the Kuroshio warm eddy usually intruded into Oyashio current to affect the distribution of Pacific saury catches. It also was found that fewer warm eddies associated with lower CPUE (9.7 metric tons / day/boat) during June to August; however, increasing twice warm eddies along with higher CPUE (19.5 metric tons / day/boat) from September to December. Moreover, there was a negative linear relationship (R2=0.35) between the distributions of Pacific saury and its distances to those warm eddies in this study.