マグロ ハエナワ ノ ジリョウ ニツイテノ ケンキュウ III : アクリル ジュシセイ N.T.フィッシングライトL.L.ガタ ニツイテ

Some investigations on the two kinds of artificial bait, N.T.fishing light, type L,L, made of Acryi resin, group A (without tetron film) and group B (with tetron film), were carried out by the Keiten Maru, training ship of the Faculty of Fisheries, Kagoshima University, in the sea-front spreading over 1°-10’N~1°-20’S and 90°-50’E~93°-20’E, during the term from 5. June to 27. the same month, 1971. The investigations were also conducted for the test of hooking rate of three kinds of real bait ; Saury, Mackerel and Mackerel Scad. The results obtained are as follows. 1. Compared with the group A, the hooked rate of the group B (fishing light L,L, with tetron film) was upon any conditions higher, without the distinction of the kind of bait or whether the bait was used or not. The fact seems to be caused by tetron-film-effect. 2. Compared with the hooking with fishing light, the hooking rate with real bait was generally higher. But partially, about one third of whole tests, cases were also observed that the former showed higher rate. The fact could be considered as to be caused by some effect of fishing light. As fishing light lasts longer, promising possibility is to be expected, when the studies in this field advans and the way of using improves. 3. The hooking rate of the real bait were different from the results of the previous report. The highest fishing-rate this time was in the Mackerel-Scad-Bait, followed by the Mackerel-Bait and the Saury-Bait, listed in the order of fishing efficiency. As confirmed here it is difficult to deduce what kind of real bait is most effective. But as far as these data concerned, one thing can be denied ; namely the so called principle that there would cause a quite unfavorable result upon the hooking rate, if especially the Saury-Bait is not used