Simulation of Age-Structured Leslie Matrix Model to Evaluate the Reproductive Values of the North Atlantic Albacore Stock

用雷氏矩陣模式模擬評估北大西洋長鰭鮪系群之生殖價

許建宗(Chien-Chung Hsu)

《臺灣水產學會刊》 26卷2期 (1999/06) Pp. 59-71

https://doi.org/10.29822/JFST.199906.0001

摘要

北大西洋長鰭鮪系群爲鮪延繩釣漁業和表層漁業（如活餌釣、曳繩釣和流網漁業）所開發利用。經由各種生產量模式和年級群分析法的評估分析，本系群經四十餘年的捕撈，已經處於完全開發的狀態。產卵母族群生物量從一九八五年以來呈下降趨勢，而且加入群量在近十年來呈劇烈的波動，但其產卵群和加入群間關係則尚未能完全確知。因此，本研究擬採用年齡別漁獲量資料，以Allen氏法估求各年加入量和加入年齡的年间變化。再據以套適產卵母族群量-加入量間的關係。研究結果期能提供該系群可信的加入群參數資訊。Allen氏加入量估計結果顯示：加入群主要依隨表層漁業的漁獲量來決定，故完全加入年齡估計爲2歲。以傳統定義五歲以上爲成魚，配合2年的時間遲延，產卵群(S)和加入量(R)間關係可以套適爲：R=16.1618e(上标 -2.10007S)（Ricker 型）及（方程式略）（Beverton and Holt型）。觀測和理論加入量比較，自1987年起有顯著差異。加入量之百分差異和產卵群量關係顯示，套適的Beverton and Holt模式比Ricker模式較合適來表現北大西洋長鰭鮪系群之產卵群和加入群關係。該模式的建構可以應用於未來系群投射的研究。

關鍵字

大西洋長鰭鮪 ； 雷式矩陣模式 ； 生殖價 ； 死亡

並列摘要

The northern Atlantic albacore stock has been harvested by longlines and surfacegears(baitboats,trolls and gillnets)for more than 40 years.Recently the stock was evaluatedin a fully exploited status through the production models and virtual population analyses.The spawning stock biomass has declined since 1985,and the recruits have showngreatly fluctuation during the recent decade.But the relationship between spawner andrecruit is not well known.Therefore,The present study uses Allen's method to estimatethe recruits and to investigate the variation between recruited ages from commercialcatch and size data.Accordingly,the spawner-recruit relationship was fitted using thosedata.The results could provide a reliable recruit parameter for the stock.Allen's recruit estimation showed that recruits mainly depended on catches of surfacefisheries,so fully recruited age 2 was investigated.Further,the mature age was set about5-year-old as usual,and two-year lag was used to relate the spawners(S)and recruits(R).Then,the spawner-recruit relationship was fitted as:Ricker type,R=16.1618e(superscript -2.10007S),andthe Beverton and Holt type,(The equation is abbreviated)The comparison between observed and predicted recruits showed that the greater discrepancyoccurred after 1987.The percentage variation in terms of spawner revealed that theformulated Beverton and Holt type was more appropriate than the Ricker type to expressthe spawner-recruit relationship for the north Atlantic albacore stock.As long as the Bevertonand Holt spawner-recruit relationship was built,the application on stock projection maybe pursued in the future.

並列關鍵字

Atlantic Albacore ； Leslie Matrix Model ； Reproductive Value ； Mortality