An Exploration on Ichthyoplankton Assemblage in the Waters off South Western Taiwan,with an Inference on the Role of Kuroshio on the Distribution of Ichthyoplankton

由臺灣西南外海浮游魚類群集的一次探測推測黑潮支流對其分布的影響

丘臺生(Tai-Sheng Chiu)

《臺灣水產學會刊》 19卷1期 (1992/03) Pp. 1-12

https://doi.org/10.29822/JFST.199203.0001

摘要

為探討長鰭鮪流刺網之網目選擇性，利用海功號試驗船以12、14、16及18公分之尼龍單絲及尼龍複線流刺網於1986年4月6日～5月8日及5月20日～6月27日兩航次在西北太平洋的32站中對長鰭鮪進行觀測。主要結果如下：1．尾叉長(FL)與最大圍長(MG)和鰓蓋後圍長(OG)的關係分別為：FL=7.275+1.334 MGFL=5.798+1.554 OG2．尼龍單絲的最高相對效率高峯尾叉長與網目尺寸之比值(K)為3.8929，50％相對效率尾叉長（FL50）位於最適正漁獲尾叉長的91％和123％，50％選擇點間的尾叉長範圍與網目尺寸之比值(h)為1.272；而尼龍複線的K值為3.7858，50％相對效率尾叉長（FL50）位於最適正漁獲尾叉長的88％和113％，h=0.944。二者間之差異主要乃是由於網線材質不同所致。3．長鰭鮪理論體長頻度分布中有3個型量，位置分別於53 cm、63 cm及79 cm，平均尾叉長為64.1 cm。4．尼龍單絲流刺網之適正網目為16.5 cm；複線則為16.9 cm。然基於經濟、社會和資源保護方面的考量，建議流刺網船仍以使用目大20～21 cm的複線流刺網為宜。

關鍵字

浮游魚類群集 ； 臺灣西南 ； 黑潮 ； 分布

並列摘要

Mesh selectivity for albacore,Thunnus alalunga,was investigated from 32fishing operations in the northwest Pacific from 4 April～8 May and 20 May～27 June,1986,using 12,14,16 and 18 cm mesh nylon monofilament and multifilamentgill nets.The study showed the following:1.The relationships between fork length(FL)and maximum girth(MG),and opercle girth(OG)wereFL=7.275+1.334 MGFL=5.798+1.554 OG2.The ratio of optimum fish length to mesh size(K value)for monofilamentgill nets was 3.8929.The fork length at 50% relative efficiency(FL50)marked at 91 and 123%,with the ratio of length range between 50% selectionpoints to the mesh size(h value)of 1.272.The K value of 3.7858 and 88 and113% fork length at FL50 with h value of 0.944 were recognized for multifilamentgill nets.The difference contributed to the difference in the gear material.3.There were three modes in the theoretical length frequency distribuionof albacore,at 53,63 and 79 cm,with the mean fork length of 64.1 cm.4.The optimum mesh size was estimated to be 16.5 cm and 16.9 cm formonofilament and multifilament,respectively.A mesh size of 20～21 cm andmultifilament gill nets is,therefore,recommended from economic,social andresource protection viewpoint.

並列關鍵字

Ichthyoplankton Assemblage ； SW Taiwan ； Kuroshio ； Distribution