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臺灣鬼頭刀族群動態解析及生態習性之研究

  • 日期:111-10-25
  • 計畫編號:110農科-6.1.2-水-A2(2)
  • 年度:2021
  • 領域:漁業科技研發
  • 主持人:林憲忠
  • 研究人員:吳瑞賢、蔡富元、許紅虹、江偉全、張綦璿

本研究以2003-2021年臺東縣新港魚市場所量測之97,211尾鬼頭刀之樣本(雌魚60,858尾,雄魚36,353尾)及根據2017-2021年新港漁獲資料分析鬼頭刀延繩釣漁獲組成。漁獲鬼頭刀體長季節及性別方面有明顯差異,組成顯示夏季群之漁獲體長較大於秋冬季。依體長分析指出7-8月及10-12月可能有兩個加入群進入臺灣東部海域。漁獲鬼頭刀性比顯示雌魚佔較優勢,總性比為0.62,但隨體長增加雄魚比例越高,因此雄魚體長較大於雌魚。鬼頭刀延繩釣漁獲鬼頭刀佔82.2%,混獲率僅17.8%,月別混獲率介於8.4-35.6%之間。鬼頭刀延繩釣漁船各月別作業海域於新港外海附近,而冬季則有逐漸北移至花蓮海域作業。
根據於臺灣東南部海域、日本鹿兒島海灣及日本長崎北部海域利用彈脫型衛星標識紀錄器(pop-up satellite archival tag, PSAT)記錄鬼頭刀5至30天的移動行為顯示,各海域所標識之鬼頭刀皆具有明顯的晝夜垂直移動模式,然而有50%以上的時間主要棲息於50公尺以淺的表層水域,夜間垂直棲息深度較白天深且持續時間更長。本研究藉由鬼頭刀漁業依賴及漁業獨立相關資訊所得之漁場時空分布變動以及水平與垂直移動行為等分析成果,將可提供作為未來進行鬼頭刀漁業管理和資源動態分析之重要科學參考依據。

研究報告摘要(英)


In this study, length-frequency and sex ratio (proportion of females) of dolphinfish were analyzed based on 97,211 (60,858 were females and 36,353 were males) samples measured in Shingkang fish market during 2003 to 2021, and catch compositions of dolphinfish longline fishery were also explored based on the catch records collected from Shingkang fish market during 2017 to 2021. There were significant differences in the length and sex ratio of the catches in the two seasons, with the length of the catch in summer being significantly greater than that in winter. However, there are two recruitment to eastern waters of Taiwan from July to August and October to December. The sex ratio shows that females are dominant, with a total ratio of 0.62. The proportion of male becomes higher than females when body length increased. The 82.2% of the catch dolphinfish for dolphinfish longline, the by-catch are only 17.8%, and the monthly by-catch shows that the between 8.4-35.6%. The dolphinfish longline vessel option area distribution off Singang waters of months, but gradually move north to Hualien coastal waters in winter. Based on the 5 to 30 days records of pop-up satellite archival tag (PSATs) attached on the dolphinfish in the southeastern Taiwan waters, Kagoshima Bay and northern waters of Nagasaki, Japan, obvious daily vertical patterns were observed for dolphinfish in all areas and indicated that dolphinfish spent more than 50% of their time staying the surface waters of the depth less than 50 m and dove deeper and for longer durations during nighttime. The outcomes related to the spatial-temporal distribution of the fishing ground and horizontal and vertical movement behavior of this study obtained through the fishery-dependent and fishery-independent data can provide scientific information for future fisheries management and analysis of population dynamics for dolphinfish.