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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences >
北海道大学水産科学研究彙報 = Bulletin of Fisheries Sciences, Hokkaido University >
第62巻 第2号 >
マナマコ種苗の放流初期における発見率低下要因
Title: | マナマコ種苗の放流初期における発見率低下要因 |
Other Titles: | Low discovery rate of sea cucumber Apostichopus japonicus juveniles after seed release in the field |
Authors: | 植草, 亮人1 Browse this author | 吉田, 奈未2 Browse this author | 柏尾, 翔3 Browse this author | 戸梶, 裕樹4 Browse this author | 浅見, 愛5 Browse this author | 中原, 功太郎6 Browse this author | 五嶋, 聖治7 Browse this author →KAKEN DB |
Authors(alt): | Uekusa, Ryoto1 | Yoshida, Nami2 | Kashio, Sho3 | Tokaji, Hiroki4 | Asami, Ai5 | Nakahara, Koutaro6 | Goshima, Seiji7 |
Keywords: | Low discovery rate | Apostichopus japonicus | Sea cucumber | Release | Juvenile | Artificial reef |
Issue Date: | 8-Aug-2012 |
Publisher: | 北海道大学大学院水産科学研究院 |
Journal Title: | 北海道大学水産科学研究彙報 |
Journal Title(alt): | Bulletin of Fisheries Sciences, Hokkaido University |
Volume: | 62 |
Issue: | 2 |
Start Page: | 43 |
End Page: | 49 |
Abstract: | Low discovery rates are common at initial stages of sea cucumber Apostichopus japonicus juveniles release, and possible causes, such as drifting away by waves, predation, burying by mud, and emigration have been suggested. In order to clarify causes of the low discovery rate, the body length and juvenile occurrence were examined by releasing juveniles into artificial reefs. We compared discovery rates among four releasing treatments; using oyster shells as attachment devices, covering whole artificial reefs with different net mesh size as 2 mm and 4 mm, and control groups which were directly released into artificial reefs. The discovery rate decreased quickly during the first 7 to 14 days after release, after that it decreased slowly. Comparison of juvenile body length between just released and 28 days after releasing groups, indicated no size-dependent disappearance pattern. Discovery rates did not differ significantly among the four releasing treatments. We discuss the other possible causes contributing to the observed low discovery rate. |
Type: | bulletin (article) |
URI: | http://hdl.handle.net/2115/49838 |
Appears in Collections: | 北海道大学水産科学研究彙報 = Bulletin of Fisheries Sciences, Hokkaido University > 第62巻 第2号
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