Effect Of Light On Squid Behaviour And Its Application For Squid Net Fishing In Malaysia
This study was carried out with the objectives of understanding the behaviour of squid in response to artificial light, determining the effects of different characters of light on squid net fishing and estimating the distribution pattern of underwater light which is currently employed by Malaysia...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English English |
| Published: |
1996
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/11822/1/FPSS_1996_4_A.pdf |
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| Summary: | This study was carried out with the objectives of understanding the
behaviour of squid in response to artificial light, determining the effects of different
characters of light on squid net fishing and estimating the distribution pattern of
underwater light which is currently employed by Malaysian fishermen. The
experiments on squids were conducted in confinement and open waters. The
distribution pattern of underwater illuminance was estimated by theoretical model.
Experiment in confined floating cage showed the response of big fin reef
squid (Sepioteuthis lessoniana) and mitre squid (Loligo chinensis) to the different
characters of artificial light. These two species prefer to remain in the underwater
illuminance ranging from 1.5 to 22.5 and 1.5 to 25.0 lux, respectively, with the
majority of both species occuring at 2.5 to 10.0 lux. However, big fin reef squid demonstrated a considerably stronger phototaxis animal than mitre squid. This was
supported by the open water study in which big fin reef squid would swim up to
the water surface with active movement, while mitre squid prefer to remain at the
sea bottom.
Studies on the effect of different characters of artificial lights used by
fishermen indicated no significant difference between CPUE and the different types
and intensities of fishing lamp. It is recommended that the intensity of light source
for Malaysian squid netting boats should be reduced and the present type fishing
lamp should be replaced by high pressure mercury lamp. The use of red and white
spotlight lamps are also recommended.
Results on the estimation of a theoretical model also confirmed that the
current usage of attracting light system was in excess of the optimum level of light
intensity for Malaysian squid fishing grounds. The efficiency of lamp and the
height of light sources installed on the boat should be considered for lighting
management. |
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