Detection of Sea Noises and Sound of Fish by Sonobuoy

Hashimoto T., Nishimura M., Maniwa Y., Hagino K., Imamura R., Akimoto K.

doi:10.9749/jina.21.0_43

The research of sea noise in the ocean or the detection of fish shoal by their swimming sound were usually made by research vessels, or, in case of set net fishing, by the line transmission of under water sound to coastal receiving stations by means of electric cable. For the purpose of listening to the sea noises of several locations simultaneously or surveying the fish location by the sound originated from fish shoal, it has been demonstrated that the "sonobuoy's disposition offers an easier and more economic survey. The observation is made by setting several sonobuoys at sea and receiving the under water sound transmitted through the radio system of a coastal station. The sonobuoy device consists of hydrophone, audio-amplifier, radio transmitter and receiver, speaker, pen-recorder and two channel magnetic tape-recorder. The sonobuoy adopts frequency modulation system at V.H.F. of 42.M.C. band and its effective communication range is up to 10km. The under water signal caught by speaker is recorded on pen-recorder or on magnetic tape-recorder. The observation by this device of the swimming sound of yellowtail in set-net fishing grounds has demonstrated that the sonobuoy can clearly distinguish the sound of yellowtail from the sea noise, and that the frequency of sound generation at the entrance of set-net has a certain relation with probable catch of fish. It is expected in future that we can tell the possibility of catch by listening to the sound of fish by means of this device. We can conclude that in feature, the forecast of fish catch may be possible by listening the sound of fish.

Detection of Sea Noises and Sound of Fish by Sonobuoy

Bibliographic Information

Search this article

Description

Journal

Details 詳細情報について

Export

Report a problem