旋網漁船の水中騒音(予報)(日本航海学会第34回講演会)

抄録

Recently, in the westsrn coasts of Japan, the structure of purse seiners was changed into steel from wood-hull. Some of fishermen say, noise of the steel boat become loud and it may be disturbed fish-gathering effects. There are many reports on the ship-borne noise by Hashimoto, Maniwa, Nishimura, E.J. Skudrzyk, J.H. Janssen, and Yoshino and others reported on the orditory sense of fish. On June 18, 1965, authors carried out a preliminary study on the ship-borne noise by purse seiners at the northern waters off Hirado Island (Table 1). The instrument principally used such as a Hydrophone (OKI 57TA), Pre-Amp (57TA-2), Tape-Recorders (SONY TC-802 and FT-2) and Sound-Spectrograph (RION, so called as Sonagraph), and those resonance characters are shown in Fig.1. The acoustic pattern and section by means of the Sonagraph are shown in Figs.2-11. By those figures, we supposed that in the case of the purse seiner, there are some correlation between the ship-borne noise and the fishing effect. And we are intending continuousely to pursuit this problem hereafter.