{"created":"2023-05-15T16:32:08.386540+00:00","id":3865,"links":{},"metadata":{"_buckets":{"deposit":"94427ab7-5eb0-45ab-9111-5ed2a2955759"},"_deposit":{"created_by":2,"id":"3865","owners":[2],"pid":{"revision_id":0,"type":"depid","value":"3865"},"status":"published"},"_oai":{"id":"oai:nagasaki-u.repo.nii.ac.jp:00003865","sets":["50:51"]},"author_link":["15714","15717","15715","15716"],"item_2_alternative_title_19":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Factors Affecting the Abundance of Pondsmelt, Hypomesus nipponensis Population in Lake Ashinoko."}]},"item_2_biblio_info_6":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1995","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"9","bibliographicPageStart":"1","bibliographicVolumeNumber":"43","bibliographic_titles":[{"bibliographic_title":"水産増殖"}]}]},"item_2_description_4":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"芦ノ湖におけるワカサギ資源の変動要因を明らかにするため, ワカサギのふ化・成長, 年齢組成について調査を行うとともに, 資源の減耗要因とくに魚食性魚類 (ニジマス, ブラウントラウトおよびオオクチバス) による捕食の影響を既存資料にもとついて検討した。結果の大要は以下の通りである。(1) ワカサギ当歳魚のふ化日推定の結果ならびに成長の様子から, 芦ノ湖のワカサギ資源の中で放流卵に由来するものの割合が大きくなってきていることを推定した。(2) 刺網や釣りの対象となる大型魚の年齢は1+歳であり, その生き残りの多寡が年々の刺網の漁獲量を大きく規定していることを指摘した。(3) 1+歳までの最大の減耗要因は, 魚食性魚類による被食であることを定量的に示した。芦ノ湖に定着しているオオクチバスは, 近年多量のワカサギを捕食するようになってきており, その影響にはとくに注意が必要である。","subitem_description_type":"Abstract"},{"subitem_description":"In order to clarify the factors affecting the abundance of Pondsmelt population in Lake Ashinoko (35°12'N, 139°E), we investigated the date of hatching, growth rate, and the age composition of pondsmelt. In addition, we estimated the seasonal and annual losses of pondsmelt due to predation by fish species present in the lake such as rainbow trout, brown trout, and largemouth bass. The results are summarized as follows: (1) It was revealed from the estimation of the date of hatching and the growth rate of pondsmelts collected in the lake that the fish originating from released eggs were more frequent than those from spawnings. (2) The 1+ age fish were dominant among pondsmelt caught by gill nets. This suggests that recent declines in the gill net catch may be chiefly caused by poor survival of the 1+ age fish. (3) The estimated loss of the pondsmelt due to the predation by other fish exceeds that due to the fishing. Likewise the percentage of pondsmelt in the diet composition of largemouth bass remarkably increased in recent years; this suggests an increase in predation pressure by the largemouth bass. Overall, these results indicate that predation is a crucial factor determining the abundance of pondsmelt in the lake.","subitem_description_type":"Abstract"}]},"item_2_description_63":{"attribute_name":"引用","attribute_value_mlt":[{"subitem_description":"水産増殖, 43(1), pp.1-9; 1995","subitem_description_type":"Other"}]},"item_2_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"15716","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Sudo, Kazuhiko"}]},{"nameIdentifiers":[{"nameIdentifier":"15717","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Nakata, Hideaki"}]}]},"item_2_publisher_33":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"日本水産増殖学会"}]},"item_2_relation_12":{"attribute_name":"DOI","attribute_value_mlt":[{"subitem_relation_type":"isIdenticalTo","subitem_relation_type_id":{"subitem_relation_type_id_text":"10.11233/aquaculturesci1953.43.1","subitem_relation_type_select":"DOI"}}]},"item_2_rights_13":{"attribute_name":"権利","attribute_value_mlt":[{"subitem_rights":"c 1995 Japanese Society for Aquaculture Research"}]},"item_2_source_id_10":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AN00124667","subitem_source_identifier_type":"NCID"}]},"item_2_source_id_7":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"03714217","subitem_source_identifier_type":"ISSN"}]},"item_2_text_62":{"attribute_name":"出版者別言語","attribute_value_mlt":[{"subitem_text_value":"Japanese Society for Aquaculture Research"}]},"item_2_version_type_16":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"須藤, 和彦"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"中田, 英昭"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2020-12-21"}],"displaytype":"detail","filename":"AquaSci43_1.pdf","filesize":[{"value":"1.0 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"AquaSci43_1.pdf","url":"https://nagasaki-u.repo.nii.ac.jp/record/3865/files/AquaSci43_1.pdf"},"version_id":"447ad540-cb47-4983-abcc-fe4a5b8008a6"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"ワカサギ","subitem_subject_scheme":"Other"},{"subitem_subject":"資源変動","subitem_subject_scheme":"Other"},{"subitem_subject":"捕食量","subitem_subject_scheme":"Other"},{"subitem_subject":"芦ノ湖","subitem_subject_scheme":"Other"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"journal article","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"芦ノ湖におけるワカサギ資源の変動要因","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"芦ノ湖におけるワカサギ資源の変動要因"}]},"item_type_id":"2","owner":"2","path":["51"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-02-13"},"publish_date":"2017-02-13","publish_status":"0","recid":"3865","relation_version_is_last":true,"title":["芦ノ湖におけるワカサギ資源の変動要因"],"weko_creator_id":"2","weko_shared_id":-1},"updated":"2023-05-16T03:27:39.778376+00:00"}