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

本研究以漁獲統計量、生物採樣、衛星遙測及現場水文觀測資料，配合主成分分析法解明2003年4月 ~ 2004年4月，台灣西南海域鯷科仔稚魚漁況及其與環境變動之關係。研究期間漁場內水文環境隨季節而有所變動，水溫大約介於22.25 ~ 29.4 ℃間，鹽度則介於31.02 ~ 34.92 psu之間。至於枋寮地區2003年1月 ~ 2004年5月之魩仔魚月別漁獲量與單位努力漁獲量 (CPUE)，分別介於1,155 ~ 71,755 kg/month與60.8 ~ 539.5 kg/day/boat之間。在漁獲魚種組成方面，以異葉公鯷及刺公鯷為主要優勢魚種，平均來游率佔95％以上，但隨時序推移，可能受到不同性質水團的影響而魚種來游比率亦隨之改變。當受到相對高溫低鹽的南海水影響時，異葉公鯷的來游比例會提高；而受到相對低溫高鹽的黑潮支流影響時，刺公鯷的來游比例較高。此外，隨著海流向岸推移，鯷科仔稚魚漁況亦有增加之現象，但隨著加入群之成長漁獲體長漸長，漁獲量則漸漸減少。另一方面，鯷科仔稚魚漁況亦與浮游動物之橈足類及毛顎類的豐度，分別呈負與正相關關係，前者應是餌料生物關係，故隨著漁場範圍內之鯷科仔稚魚來游比例越高，則其餌料生物橈足類比例越少；而後者則可能與外洋水之推移有關。

The fishing conditions of the anchovy larval fishery and the hydrographic environment in the waters off southwestern Taiwan were investigated during the period of January 2003 to May 2004. Temperature varied between 22.3 and 29.4 °C and salinity between 31 and 34.9 psu. The monthly catch varied between 1,155 and 71,755 kg and the catch per unit effort (CPUE) between 60.8 and 539.5 kg/day/boat. The anchovy larvae were dominated by Encrasicholina heteroloba and E. punctifer, which contributed 95% to the total number of larvae, while the larvae of Engraulis japonicus comprised less than 5%. The abundance of E. heteroloba and E. punctifer larvae changed with the water mass. Encrasicholina heteroloba was abundant when the South China Sea Warm Current prevailed, while E. punctifer was abundant when the Kuroshio Branch Current prevailed; the Kuroshio has a higher salinity than the South China Sea Warm Current. The monthly CPUE of larval anchovy was positively related to the temperature gradient of sea surface temperatures, and negatively related to the body length of the fish. The abundance of larval anchovy in relation to the zooplankton composition is discussed.