灯火漁業の研究-II

サバの跳ね釣りについて

抄録

The mackerel angling (with pole and line) fishery has been operating at night with lureing lamps in the off-shore of around of Japan.
For the investigation, the following five fishing grounds were selected, surrounding of Saishu Island, off-shore of Senzaki, Tsugaru Channel, East China Sea, and southern sea of Kyushu (Satsunan Sea area).
In this studies, the difference of catches among these five fishing-grounds was discussed through two points of view of light intensity of lureing lamps and echo of fish-finder from shoals.
Consequently, it was found that the adaptability of light intensity to catch mackerel was changed by fishing-ground, the most powerfur light was neccessary in the East China Sea and other fishing-grounds were arranged in order of light intensity as follow; Saishu Island, Southern Sea of Kyushu, Senzaki and Tsugaru fishing ground and this order was given in propotion to depth of swimming layer of shoals in each fishing-ground and the degrees of sea transparency. It was also found that the use of fish-finder had brought about a remarkable effect on catches.