TRAWL FOR FISHING IN BOTTOM ZONE Russian patent published in 2004 - IPC

FIELD: fishing; trawls.

SUBSTANCE: proposed trawl consists of pelagric net trawl and towed acoustic concentrator of rotary type. Concentrator forms extended fish barrier-acoustic field in water by means of acoustic radiator. Field is periodically interrupted and is changed after each pause in spectral composition. Field encloses upper half of trawl net and corresponding sector of water space before trawl. Lower part of trawl net is periodically covered by short-time acoustic pulses, part of which getting in ground causes bottom reverberation. Spectrum of re-reflected acoustic signals from and out of ground makes fish separate from bottom and rise to zone of fishing of net trawl where fish is held from dispersing by acoustic field enclosing upper part of trawl net.

EFFECT: provision of effective fishing at sea bottom, even on complex submarine relief.

3 dwg