您的 Browser 不支援 Javascript , 但是並不會影響您觀看本站的內容 跳到主要內容區塊

研究報告

更新日期: 2015-02-09
點閱數: 1,587

北太平洋長鰭鮪資源研究

年度 2013
計劃名稱 北太平洋長鰭鮪資源研究
中文摘要 本研究以作業模式及漁獲結果將北太平洋作業之臺灣鮪延繩釣漁業區分為兩種漁業,以分群後的資料進一步分析長鰭鮪長期變動趨勢。並依據1995~2011年北太平洋捕獲漁獲組成及漁業資料之分布特性進行漁區劃分,各漁區特性包含漁業(漁獲組成、努力量)及生物(體長)特性有明顯差異。分區結果用為GLM標準化CPUE參數之一,合理反映我國北太平洋長鰭鮪漁業訊息。標準化CPUE trend在2000年震盪幅度並不明顯,長期趨勢都維持在小幅度的變動。長鰭鮪在2003年後紀錄體長增大,又以北緯25度以南體長較北側大、非以長鰭鮪為目標的漁獲體長較以長鰭鮪為目標的漁獲大。年齡結構在1995~2002年以2~4歲魚為主,2003~2011年以4~6歲魚為主。以我國北太平洋鮪延繩釣漁業統計資料分析長鰭鮪移動模式的初步成果,5歲(含)以下中幼齡長鰭鮪的每月CPUE重心均在北緯25度以北,6歲(含)以上長鰭鮪CPUE重心在6、7月南移至熱帶、亞熱帶海域,8歲(含)以上的CPUE重心在9~3月似乎有以逆時針方向洄游的情形。本年度分別於3月19~26日於中國上海及11月5~12日於日本清水參加ISC長鰭鮪工作小組會議,會議中參與檢視過去訂定的主要研究工作及討論2014年資源評估相關研究,提出我國北太平洋長鰭鮪研究結果。會議中提出的報告有(1)Development of Taiwanese albacore-targeting longline fisheries in the North Pacific Ocean, 1995-2010.(2)Taiwanese albacore-targeting longline fisheries in the North Pacific Ocean, 1995-2011.
英文摘要 In order to gain a better knowledge of abundance index for the north Pacific albacore exploited by Taiwanese longliners, the generalized linear model (GLM) was applied to the daily logbook records of albacore-targeting fleets, which were defined based on their fishing activities and resultant catch compositions. In the GLM analyses, several sub-area segregations were adopted, and results showed that 2 sub-areas divided by 25oN Lat. can explain the highest proportion of variance either for the model or for the area factor itself. The GLM results revealed that the standardized CPUE fluctuated within a rather small range, suggesting that the north Pacific albacore population is currently under a reasonable exploitation, particularly since 2001.In this study, we also investigate the age compositions of north Pacific albacore based on length frequency data, given by OFDC, and growth equation reported by Wells et al. (2013). In the period 1995-2002, the albacore catch of Taiwanese longliners were mainly contributed by fish of age 2-4. Since 2003, significant proportion of the albacore catch was comprised of age 4-6 groups. Seasonal differences in the geographical distributions between age groups were observed. The CPUE gravity centers of albacore at age 5 and younger remained in the waters north of 25o N Lat. throughout the year, while those of fish older than 5 years tended to move down to the subtropical and tropical waters in June and July. Based on the monthly distribution of CPUE gravity center, those of fish older than 7 years likely move counter clockwise in the central north Pacific Ocean in the period of September-March.
計畫編號 102農科-11.1.1-漁-F4(3)
網站導覽錨點