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來源資料
頁籤選單縮合
| 題 名 | Acoustic Estimation of Biomass and Dispelling of Larval Anchovy Herded by Large-mesh Wings of Trawlnet=大目袖網驅集鮆科稚魚魚群量之評估 |
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| 作 者 | 李明安; 李國添; 王振培; | 書刊名 | 臺灣水產學會刊 |
| 卷 期 | 22:1 1995.03[民84.03] |
| 頁 次 | 頁15-22 |
| 分類號 | 439.3 |
| 關鍵詞 | 聲探評估; 鮆科仔稚魚; 大目袖網; Acoustic estimation; Larval anchovy; Large-mesh wings; |
| 語 文 | 英文(English) |
| 中文摘要 | 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為742g/m3,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,至於其比值則與平均漁獲體長成正相關,平均漁獲比率為63%;亦即漁 獲作業過程中有37%之魚群量被濾過或驅散。 |
| 英文摘要 | Density of larval anchovy (Engraulis japonicus, Encrasicholina punctifer, and E. heteroloba) was estimated, using the hydroacoustic method, at the mouth of large-mesh wings of trawlnet during the fishing operation. The biomass of the larvae in the water trawled was estimated, and compared with the catches in the cod net to determine the dispelling rate. 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 that instead of direct escaping, the filtration of small, feeble larvae through large meshes of the wings is a primary mechanism of the dispelling phenomenon. |
本系統中英文摘要資訊取自各篇刊載內容。