Nippon Suisan Gakkaishi 79 (5), 785-792 (2013)

Catch performance of coastal squid jigging boats equipped with underwater lamps having a shading structure

DAISAKU MASUDA,1a* SYUYA KAI,1 HIDEKI MAEKAWA,1b
YUKIKO YAMASHITA2 AND YOSHIKI MATSUSHITA2

1Nagasaki Prefectural Institute of Fisheries, Taira-machi, Nagasaki 851-2213, 2Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo-machi, Nagasaki 852-8521, Japan

This study examined the possibility of using underwater lamps in coastal squid jigging fishery. Fishing trials were carried out from 2009 to 2011 using coastal squid jigging boats (6.4-6.6 t) equipped with an underwater lamp apparatus with a shade to create high/low light intensity fields in the water column. The catch amounts of the squid jigging boats with the underwater lamp apparatus (experimental boats) were compared with the catch of a control boat equipped with conventional surface lamps, which simultaneously operated in the same water. The catch amounts of the experimental boats were significantly less than that of the control boat (p<0.05). However, catch amounts were expressed as functions of squid abundance, lunar phase, tide, presence of dolphins and wind direction, and the effect of using the underwater lamp apparatus was insignificant in the generalized linear modeling analysis. Thus, the underwater lamps did not increase squid catch, but were considered useful for controlling the depth of squid aggregation by changing the depth of the lamps.


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