台灣周邊海域鮪類仔稚魚之年別分布與豐度

陳郁凱、王友慈、潘佳怡、吳繼倫、劉燈城 (2013) 。臺灣周邊海域鮪類仔稚魚之年別分布與豐度。水產研究，頁13-24。

       為瞭解台灣周邊海域鮪類仔稚魚之分布與豐度，本研究於2005年、2007年及2009年的春季與夏季期間，以水試一號試驗船在台灣周邊海域62個測站進行五個航次的仔稚魚調查，利用ORI浮游生物網共採得鮪類仔稚魚131尾，其中包含長鰭鮪 (Thunnus alalunga) 28尾、黃鰭鮪 (T. albacares) 48尾、大目鮪 (T. obesus) 28尾及黑鮪 (T. orientalis) 27尾，春季及夏季均以黃鰭鮪捕獲比例最高，其餘三種鮪類差異不大。春季時期，長鰭鮪、黃鰭鮪、大目鮪及黑鮪仔稚魚捕獲測站之平均表水溫分別為27.1、27.1、27.2及27.5 ℃；夏季時期，分別為30.3、30.1、29.9及30.2 ℃。調查結果顯示，春季及夏季時鮪類仔稚魚主要捕獲地在台灣東部黑潮流域以及西南海域黑潮支流與南海水混合域，多出現於外洋區，近岸區僅有零星分布。本研究中發現鮪類仔稚魚在不同年間的出現密度與位置不同，可能是由於水溫、鹽度或餌料生物的變動所造成，然仍須正確掌握產卵場地點以瞭解仔稚魚的棲息環境，方能釐清造成年間差異的確切原因。

      In order to understand the distribution and abundance of tuna larvae in the surrounding waters of Taiwan, samples from five cruises were examined, which included 62 stations in 2005, 2007 and 2009. A total of 131 larval tuna were collected using an ORI net, including samples of T. alalunga (28), T. albacares (48), T. obesus (28) and T. orientalis (27). T. albacares larvae were most abundant in spring and summer. In spring, the ambient sea surface temperatures for T. alalunga, T. albacares, T. obesus and T. orientalis were 27.1, 27.1, 27.2 and 27.5 ℃, respectively. In summer, the ambient temperatures for T. alalunga, T. albacares, T. obesus and T. orientalis were 30.3, 30.1, 29.9 and 30.2 ℃, respectively. The results showed that tuna larvae were found primarily in the Kuroshio Current and the Kuroshio Branch Current mixed with South China Sea Surface Water. More tuna larvae were found in the oceanic area than in the coastal area. The distribution patterns and abundances measured differently in different years, which might relate to the fluctuation of water temperature, salinity or prey abundances. Further studies should be designed to locate the spawning grounds and to collect the information regarding the ambient environment of the tuna larvae in order to figure out the causes of annual differences.