著者
土居 隆秀 中村 智幸 横田 賢史 丸山 隆 渡邊 精一 野口 拓史 佐野 祐介 藤田 知文 TAKAHIDE DOI TOMOYUKi NAKAMURA MASASHI YOKOTA TAKASHI MARUYAMA SEIICHI WATANABE HIROFUMI NOGUCHI YUSUKE SANO TOMOFUMI FUJITA 栃木県水産試験場 (独)水産総合研究センター 東京海洋大学海洋生物資源学科 東京海洋大学海洋環境学科 東京海洋大学海洋生物資源学科 東京海洋大学海洋環境学科 東京海洋大学海洋環境学科 東京海洋大学海洋生物資源学科 Tochigi Prefectural Fisheries Experiment Station Freshwater Fisheries Research Division National Research Institute of FIsheries Science Department of Aquatic Biosciences Department of Marine Environmental Sciences Tokyo University of Marine Science and Technology Department of Aquatic Biosciences Department of Marine Environmental Sciences Tokyo University of Marine Science and Technology Department of Marine Environmental Sciences Tokyo University of Marine Science and Technology Department of Aquatic Biosciences
出版者
The Japanese Society of Fisheries Science
雑誌
日本水産学会誌 = Bulletin of the Japanese Society of Scientific Fisheries (ISSN:00215392)
巻号頁・発行日
vol.70, no.5, pp.706-713, 2004-09-15
参考文献数
28
被引用文献数
2 3

イワナ・ヤマメ養殖魚の小型魚と大型魚の釣獲放流後の死亡率と成長を実験池において調査した。餌釣り,毛鈎釣りともに,口腔にかかった鈎を除去した場合,いずれの魚種においても死亡率は低かった。餌釣りで口腔より奥にかかった鈎を除去した場合,イワナ小型魚とヤマメ大型魚では死亡率は高かった。口腔にかかった毛鈎を残留させた場合,イワナ大型魚では死亡率は高かった。死亡のほとんどが釣獲放流後14日以内に観察された。釣獲方法,鈎がかりの部位,鈎の処理方法は成長と肥満度に影響しなかった。Mortality and growth of Japanese charr Salvelinus leucomaenis and masu salmon Oncorhynchus masou masou after catch and release were examined in experimental ponds, using hatchery-reared fish divided into smaller (< 15 cm in total length) and larger (> 15 cm) size groups. When the hooks stuck in the mouth and were removed for both species, the mortality within 21 days after catch and release was low (O-15.0%) for each size and fishing gear (bait and fly-fishing, using barbed hooks). When hooks in bait fishing were removed from the esophagus, mortalities were relatively high (66.7% in the smaller sized charr and 45.0% in the larger sized salmon). All the fish of both species and both size groups were alive when the hooks in fly-fishing were removed from the mouth, however the mortality was relatively high (40.0%) when the hooks were not removed from the mouth of the larger sized charr. 0f all the fish that died, 63.0 and 98.1% died within 3 and 14 days after catch and release, respectively. There was no negative effect of the catch and release on the growth and condition factor of both species and both size groups. These results suggest that catch and release is effective for conserving Japanese charr and masu salmon populations in rivers and lakes when anglers pay attention to the removal of hooks.
著者
松川 康夫 張 成年 片山 知史 神尾 光一郎 YASUO MATSUKAWA NARITOSHI CHO SATOSHI KATAYAMA KOICHIRO KAMIO (独)水産総合研究センター中央水産研究所 (独)水産総合研究センター中央水産研究所 (独)水産総合研究センター中央水産研究所 (株)東京久栄 National Research Institute of Fisheries Science Fisheries Research Agency National Research Institute of Fisheries Science Fisheries Research Agency National Research Institute of Fisheries Science Fisheries Research Agency Tokyo Kyuei Co. Ltd.
出版者
The Japanese Society of Fisheries Science
雑誌
日本水産学会誌 = Bulletin of the Japanese Society of Scientific Fisheries (ISSN:00215392)
巻号頁・発行日
vol.74, no.2, pp.137-143, 2008-03-15
参考文献数
60
被引用文献数
8 28

我が国のアサリRuditapes phillipinarumの総漁獲量は,1960年には10万トンであった。その後,一部に漁場の埋め立てによる減少があったにも関わらず,1982年には14万トンまで増加したが,1984年から激減して,1994年にはわずか3分の1程度(5万トン)になり,その後もこの水準が続いている。著者らはアサリの生態や資源に関する報告を総括し,1984年以降のアサリ漁獲量の激減の主要因を過剰な漁業活動,すなわち親貝と種貝用の稚貝に対する過剰漁獲と結論づけた。それ以外にも,周年の過剰操業による底質擾乱は,稚貝の生残率低下を助長した可能性が高いと考えられる。The annual catch of the Manila clam Ruditapes phillipinarum in Japan increased from 100 thousand tonnes in 1960 to 140 thousand tonnes in 1982. This increase occurred despite a local decrease in coastal fishing grounds due to land reclamation and helped to balance overall production. Since 1984, however, the catch has decreased drastically to only 50 thousand tonnes and has remained at this low level. The authors reviewed published reports relevant to the ecology and resources of Manila clam and concluded that the main factor responsible for the drastic decrease in catch is over-fishing. Over-exploitation of the adults and sub-adults significantly affected and damaged reproduction and source-sink relationships among localities. Disturbance of the clam habitat throughout the year by heavy fishing gear may also be responsible for lowering the survival rate of the juveniles.