LED水中集魚灯を装着した定置網の漁獲に関する報告 : 島根県浜田市における定置網漁業の試行事例

Fish catches by the use of set nets equipped with LED underwater fishing lamps: a preliminary experiment on set net fishing in Hamada, Shimane Prefecture

Creators Tanoue Hideaki

Creators Mohri Masahiko

Creators Tatewaki Hideaki

Creators Kajikawa Yoritake

Creators Satoh Shun

Creators Nakamura Takeshi

Creators Kawasaki Junji

Creators Ruitton Sandrine

Creators Mizuguchi Chizuo

Creators Hamano Akira

Creators Yoshimura Kazumasa

From July 14 to November 14, 2011，experimental fisheries were carried out grounds off Hamada, Shimane Prefecture. For 31 of 62 fishing days, LED underwater fishing lamp was switched on lighting entrance of the set net. The catches of the main fish species were checked using the fisheries diaries and slips of landed fishes. The total catches for all days of the experiment were 7,890 kg. The fishing biomass was higher when the light was switched on (4,692 kg) than it was off (3,198 kg). When the light was on, the most caught fish was Japanese jack mackerel, whose catches accounted for 24% of the total hauls. Threeline grunt constitutes 23% of the fishing, squids,14% and yellowtails, 11%. As a result, no significant difference was observed in the composition of fish species caught between the two types of lighting condition. However, the catches of the top three species, which are regarded as species having a positive phototaxis, tend to increase when the light was on. The catches of yellowtails, species with a low phototaxis, were sporadic, independent of the light, but mostly of small individuals (70 cm or less in body length). As a matter of fact, these phenomena may be the effect of LED underwater fishing lamps and suggested that small and large individuals of yellowtails could be influenced in different way. More detailed investigations would be required to look into this issue.

[ISSN]0370-9361