2013 Fiscal Year Final Research Report
Initiation of sustainable trap cage fisheries improved by observation of behaviors of North Pacific giant octopus
| Project/Area Number |
24658164
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
General fisheries
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| Research Institution | Hokkaido University |
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Principal Investigator |
SAKURAI Yasunori 北海道大学, 大学院水産科学研究院, 教授 (30196133)
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| Co-Investigator(Kenkyū-buntansha) |
NORO Kyosei 青森県産業技術センター, 水産総合研究所, 総括研究管理員 (00508343)
YAMAMOTO Jun 北海道大学, 北方生物圏フィールド科学センター, 助教 (10292004)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | ゴーストフィッシング / タコ篭漁 / ミズダコ / 飼育実験 / 脱出口装着 / バイオテレメトリ / 改良型タコ篭 / 資源管理型漁業 |
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| Research Abstract |
North Pacific giant octopus is caught by the trap cage for octopus in the coast water of northern Japan. However, the catch is gradually decreasing after 2000. The causes were estimated by the bycatch of small octopus under 3kg BW and cannibalism between octopuses in cage.
The aim of this study is to develop improved trap cage for escaping the small octopus. We observed some behaviors of giant octopus in captivity, such as entering into cage, positioning in cage, aggressive behavior and cannibalism between octopuses in cage. After that, we attached the several size of circular ring in the side net of cage. We found that small octopus under 3 kg can escape through the ring of 55 mm in diameter in the side net from cage. We also examined octopus behavior around the setting trap cages by biologging methods. Then, we confirmed that 3 kg octopus was not caught by the improved trap cage. This new trap cage will be more useful for the local octopus fisheries management in the northern Japan.
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