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

本文依據臺灣鮪延繩釣漁業於1968年至2003年的漁獲統計資料，使用泛線性模式進行北大西洋長鰭鮪資源豐度指標的標準化。Wu et al. (2006) 使用聚落分析法，將北大西洋長鰭鮪漁場分為3個亞漁區。此漁區之劃分被引用於本研究中。標準化模式共採用了年、季、漁區和大目鮪四個效應，而以漁區效應的影響最大，顯示適當的亞漁區劃分是得到良好豐度指標所必要。由北大西洋長鰭鮪資源豐度指標標準化結果顯示：(1) 此資源豐度自1968年的幾年期間呈現大幅衰退，但之後已呈現回穩直到1993年；(2) 1993年後，本資源再次呈現下降，直跌至2000年的歷史性低點；(3)最近幾年的資源豐度有上升的傾向。

Trends of the catch per unit effort (CPUE) of northern Atlantic albacore (Thunnus alalunga) data from the Taiwanese longline fishery were standardized using a generalized linear model (GLM) for the period 1968 to 2003. To construct a GLM, factors of year, quarter, area, and catch level of bigeye tuna (T. obesus) were determined and used. Three sub-areas in the North Atlantic defined by Wu et al. (2006) were adopted for the standardization process. The area factor was the most important source of variability, which indicates that a proper aggregation of sub-areas is essential for obtaining a better abundance index. The standardized CPUE trend thus obtained showed (1) a rapid decrease after 1968 to a leveling off in 1993; (2) a sharp decline after 1993 to a nadir in 2000; and (3) a rising trend in the most recent few years.