3 0 0 0 OA 日本海沖合漁場におけるイカ釣り漁業用青色 LED 漁灯の性能評価
- 著者
- 四方 崇文 山下 邦治 白田 光司 町田 洋一
- 出版者
- 公益社団法人 日本水産学会
- 雑誌
- 日本水産学会誌 (ISSN:00215392)
- 巻号頁・発行日
- vol.78, no.6, pp.1104-1111, 2012 (Released:2012-11-28)
- 参考文献数
- 21
- 被引用文献数
- 4 7
調査船に LED 灯を装備してスルメイカを対象にしたイカ釣り操業を行った。メタルハライド(MH)灯 78 灯による操業を基準に比較したところ,LED 灯単用操業では漁獲量は大きく減少したが,LED 灯 216 灯と MH 灯 24 灯の併用操業では漁獲量の減少が小さく,漁灯点灯のための燃油消費は大幅に減少した。以上より,両灯を併用することで漁獲量をある程度維持しつつ燃油節減できることが分かった。MH 灯に比べて LED 灯は船体近くの限られた範囲にのみ光を放射しており,配光の違いが漁獲性能を左右すると考えられた。
The data base of digital images of good catch conditions is not sufficient, but that of poor catches is indispensable to apply the vertical distribution of water temperature to fishing information system in order to decide the position of squid jigging in the Japan Sea. The 63 stations yielding less than 200 squids in more than 4 hours consecutive swings were sorted out, as the examples of poor catch conditions among 416 jigging records from 1982 to 1988. In this report, the data base of digital images of poor catches was examined by the group average method of cluster analysis.<br> As for the results, the digital images of poor catches having mutually high similarity were pigeonholed into 15 small groups (=clusters), although there remained 17 independent images, and they were then divided into 2 large groups, which were in relation to the area division in the Japan Sea. Some small clusters consisted of the digital images within the same year, their component images were from one of the two areas and within 30 calendar days. Other clusters consisted of those in the different years, but the individual images in each of them were also from the same area and within 30 calendar days. This tendency is helpful in quasi-real time application of the data base of the fishing information system on board.<br> On the basis of the results, a general flow chart for fishing information system was proposed.