Effects of specifications of branch line on sinking characteristics of hooks in Japanese tuna longline
Effects of specifications of branch line on sinking characteristics of hooks in Japanese tuna longline
复制标题
日本金枪鱼延绳钓支线规格对鱼钩下沉特性的影响
DOI：
10.2331/suisan.71.33
复制
发表时间：
2005
影响因子：
0.4
通讯作者：
T. Arimoto
中科院分区：
文献类型：
--
作者：
F. Hu;M. Shiga;K. Yokota;D. Shiode;T. Tokai;Hisaharu Sakai;T. Arimoto
为了制定减少金枪鱼延绳钓ˆ渔场意外捕捞海鸟的缓解措施，对日本金枪鱼延绳钓渔船使用的10种支线的鱼钩下沉速度进行了调查。此外，为提高吊钩的下沉速度，还试验了两种新工艺：将靠近吊钩10m线的材料由聚酰胺单ˆ纤维改为‰碳素，并在吊钩上增加了1560GW的重量。10条支线中0~10m深的吊钩平均下沉速度在0.16~0.23m/S之间。然而，假设ˆShing船的浇注速度为10节，十种类型的吊钩都没有在船尾150m范围内沉入超过10m的深度，也就是惊鸟彩带(环杆)的有效区域(Š)。‰超碳线吊钩下沉速度是聚酰胺单ˆ吊钩下沉速度的1.6倍。额外重量为45GW的鱼钩下沉速度几乎是传统鱼钩的两倍。
To develop mitigation measures for reduction in incidental catch of seabirds in tuna longline ˆsheries, the hook sinking speed in ten types of branch lines used by Japanese tuna longline vessels was investigated. Also, to improve sinking speed of the hook, two new techniques were tested: material of 10 m line close to the hook was altered from polyamide monoˆlament to ‰uorocarbon; and a weight of 1560 gw was added to the hook. The average sinking speed of the hooks from 0 to 10 m in depth varied from 0.16 to 0.23 m/s in the ten types of branch lines. However, assuming the speed of the ˆshing vessel for casting is 10 knots, no hook of the ten types sank deeper than 10 m within 150 m from stern, that is, the eŠective area of the bird-scaring streamer (Tori-pole). The sinking speed of the hook with ‰uorocarbon line was 1.6 times faster than that with polyamide monoˆlament. The hook with additional weight of 45 gw sank almost two times faster than the conventional one.