Stock Assessment of Albacore in the Indian Ocean By Age-Structured Production Model

應用年齡群化生產量模式評估印度洋長鰭鮪系群

許建宗(Chien-Chung Hsu)

《臺灣水產學會刊》 22卷1期 (1995/03) Pp. 1-13

https://doi.org/10.29822/JFST.199503.0001

摘要

利用聲探回訊評估法立體而連續之定量觀測魚群量及其行動的方法已漸受重視，本報告利用聲探系統配合漁獲試驗，偵測大目袖網內外鮆科稚魚魚群量之變化情形。結果顯示利用聲探回訊積分法求得袖網間驅集鮆科稚魚之最大魚群密度爲742 g/m^(3)，並未超過利用聲探回訊積分法推估鮆科稚魚之界限密度，故以聲探回訊積分法推估大目袖網驅集魚群量是可行的，至於大目袖網之驅集魚群量與漁獲量間則呈一良好線性關係，亦即魚群量愈高，漁獲量也愈高，至於其比値則與平均漁獲體長成正相關，平均漁獲比率爲63％；亦即漁獲作業過程中有37％之魚群量被濾過或驅散。

關鍵字

長鰭鮪 ； 年齡群化生產量模式

並列摘要

Density of larval anchovy(Engraulis japonicus,Encrasicholina punctifer,and E.heteroloba)was estimated,using the hydroacoustic method,at the mouth of large-mesh wingsof trawlnet during the fishing operation.The biomass of the larvae in the water trawledwas estimated,and compared with the catches in the cod net to determine the dispellingrate.On the average 37% of larval biomass were dispelled during the fishing operation.The dispelling rate increased with the decrease in size of the larvae.This suggested thatinstead of direct escaping,the filtration of small,feeble larvae through large meshes ofthe wings is a primary mechanism of the dispelling phenomenon.

並列關鍵字

Albacore ； Age-Structured Production Model