PRELIMINARY OBSERVATION ON THE USE OF UNDER -WATER LIGHT IN FISH CATCH

Abstract

Experiments with drift gill net] with under-water lights were
carried out in the sea and estuarine region along with a control net of
the same specifications without any light in the same fishing ground
for comparison. The experimental net caught more fish in number
and weight than the control. Fishes like pomfrets (Pampus chinensis,
Parasfromafeus niger), seer (Scomberomorus spp), hilsa (lfisha spp)
etc showed positive phototaxis and were giBed encircling the point of
iHumination. Young skates (Mobu!a spp) and Po!ynemus tetradacty!
us were antiphototactic. The number of fishes caught increased
with increase in period of iHumination. The catch of larger fishes
was maximum at 60 mts of i11umination and the total catch increased
with increase in intensity of light. Additional cost of operation with
under-water light was Rs 1-25 per hr but the catch was 4 to 5 times
greater than that of the control net.