{"created":"2024-10-03T01:16:00.074878+00:00","id":2010795,"links":{},"metadata":{"_buckets":{"deposit":"0a040f6c-9a25-428c-92b8-1f18cf29d8e2"},"_deposit":{"created_by":10,"id":"2010795","owners":[10],"pid":{"revision_id":0,"type":"depid","value":"2010795"},"status":"published"},"_oai":{"id":"oai:fra.repo.nii.ac.jp:02010795","sets":["1:8:1724311990533"]},"author_link":["630"],"control_number":"2010795","item_10002_alternative_title_1":{"attribute_name":"その他（別言語等）のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"H. circularisquama赤潮の発生および分布拡大機構に影響する環境要因等の解明","subitem_alternative_title_language":"ja"}]},"item_10002_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2003-03","bibliographicIssueDateType":"Issued"},"bibliographicNumberOfPages":"82","bibliographicPageEnd":"105","bibliographicPageStart":"24","bibliographicVolumeNumber":"7","bibliographic_titles":[{"bibliographic_title":"水産総合研究センター研究報告","bibliographic_titleLang":"ja"},{"bibliographic_title":"Bulletin of  Fisheries Research Agency","bibliographic_titleLang":"en"}]}]},"item_10002_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Heterocapsa circularisquama Horiguchi (Dinophyceae) is a causative agent of red tide, and appeared in 1988 for the first time and then rapidly dispersed off the costal waters of western Japan. The red tide due to H. circularisquama was associated with massive killing of commercially important bivalve species: manila clam Ruditapes philippinarum, Pacific oyster Crassostrea gigas, pearl oyster Pinctada fucata, blue mussel Mytilus galloprovincialis, etc. Until 2000, 43 cases of H. circularisquama red tide (including 18 incidences leading to fisheries damage) had been recorded in western Japan. Economic losses in shellfish aquaculture by direct killing of marketable products were estimated to be at least 10 billion-yen in the last decade. Although H. circularisquama blooms mainly affect bivalve aquaculture, no harmful effects on wild or cultured fish, other marine vertebrates, or any public health hazard were recorded. Therefore, this phenomenon is referred to as a \"novel red tide.\" The red tide due to H. circularisquama has damaged shellfish aquaculture in most of the region, in terms of mass mortality in farming organisms, cost of measures to prevent the damage, adverse affects on the development of shellfish aquaculture, and secondary damage, i.e. decline of demand due to misinformation. Incidence of this species has increased recently, and the economic losses in aquaculture have been a cause for concern for the industry and society. In the present study, environmental conditions conducive to the red tide occurrence was conducted, in order to clarify the environmental factors causing H. circularisquama red tide. Frequent field surveys were carried out for four years in two representative locations (Ago Bay and Hiroshima Bay) of recurring H. circularisquama red tides. As a result, dense assemblages of H. circularisquama cells were found in the innermost part of the inlets, but not offshore or in the channels. The distribution pattern of H. circularisquama appears to be strongly affected by the water exchange rate. The red tide of H. circularisquama occurs between July and November in the embayments of western Japan. Generally, H. circularisquama blooms appear mainly under high water temperature (>23˚C) and salinity (>30psu) conditions. The results of field surveys suggested that H. circularisquama grows well under high water temperature and salinity conditions. In Ago Bay, strong disturbances of the water stratification by typhoons during the development of highly anoxic water at the bottom had preceded the large-scale red tide outbreaks of H. circularisquama in summer. Temporary or sustained water mixing throughout the water column may provide large amount of nutrients and growth -promoting substances from the bottom to the photic layer, which trigger the H. circularisquama red tide. Further, H. circularisquama sometimes caused red tides during an ecological niche opening, e.g. decline of predominant diatom populations due to several hydrographic events such as development of highly stratification associated with anoxic water in summer, decreases of light intensity and increase of vertical transportation to the non-photosynthetic layer from late autumn to early winter. In some cases, populations of H. circularisquama were affected by the predation of heterotrophic dinoflagellate Gyrodinium dominans and oligochin ciliates. The red tides of H. circularisquama has rapidly increased since the late 1980s. Relationships between the recent proliferation of H. circularisquama and changes of water qualities were analyzed covenanting various environmental factors. First, laboratory study showed that maximum growth was observed at water temperature of 32.5℃ and no growth was observed under 11.2˚C. H. circularisquama is presumed to be the tropical dinoflagelltate, so that winter water temperature is considered as the most limiting factor for the prolifelation of this species. On the Japanese coast, however, the water temperature in winter has increased about 1.0~1.2℃ since the late 1980s, probably due to global climate change. This long-term hydrographic change may be conducive to the overwintering of H. circularisquama, which has led to the recurring of red tide in Japanese coastal waters. Second, H. circularisquama blooms are sometimes observed in non-eutrophicated areas, therefore, this dinoflagellate is likely to be adapted to oligotrophication, especially in low phosphorus conditions. In Japan, administrative efforts have been carried out to reduce nutrient loading from land to the coastal sea in the last two decades. The selective improvement in the phosphorus load brought about a change in the nutrient balance, such as an increase of the N:P ratio in coastal waters. Nitrogen and phosphorus demands from H. circularisquama are much lower than other causative red tide species such as Chattonella spp. and Karenia mikimotoi, and can utilize various dissolved organic phosphorus (DOP) for their growth using alkaline phosphatase in their cell surface. This physiological characteristic is important to clarify the growth strategy of this specie. Third, simulated experiments have revealed that H. circularisquama could easily migrate to distant areas in association with shellfish transportation. The rapid development of H. circularisquama since the late 1980's appears to be caused in part by the artificial dispersal due to aquaculture operations. The developments of monitoring systems for H. circularisquama are important in order to reduce the fisheries damage. The key factors affecting long-term prediction of H. circularisquama bloom is winter water temperature, precipitation in early summer, increase of water temperature, and the development of anoxic waters at the bottom. Further, temporary mixing of the water column by typhoon events and/or niche opening due to decline of predominant diatom populations is also important for the red tide development.","subitem_description_language":"en","subitem_description_type":"Abstract"}]},"item_10002_publisher_8":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"水産総合研究センター","subitem_publisher_language":"ja"}]},"item_10002_relation_16":{"attribute_name":"情報源","attribute_value_mlt":[{"subitem_relation_type_id":{"subitem_relation_type_id_text":"fra_k_7_24","subitem_relation_type_select":"Local"}}]},"item_10002_relation_17":{"attribute_name":"関連サイト","attribute_value_mlt":[{"subitem_relation_name":[{"subitem_relation_name_text":"日本農学文献記事索引（AgriKnowledge）"}],"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://agriknowledge.affrc.go.jp/RN/2010671201","subitem_relation_type_select":"URI"}}]},"item_10002_source_id_11":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AA11589591","subitem_source_identifier_type":"NCID"}]},"item_10002_source_id_9":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"1346-9894","subitem_source_identifier_type":"PISSN"}]},"item_10002_version_type_20":{"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_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"open access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_abf2"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorAffiliations":[{"affiliationNameIdentifiers":[],"affiliationNames":[{"affiliationName":"","affiliationNameLang":"ja"}]}],"creatorNames":[{"creatorName":"Matsuyama, Yukihiko","creatorNameLang":"en"},{"creatorName":"松山, 幸彦","creatorNameLang":"ja"},{"creatorName":"マツヤマ, ユキヒコ","creatorNameLang":"ja-Kana"}],"familyNames":[{"familyName":"Matsuyama","familyNameLang":"en"},{"familyName":"松山","familyNameLang":"ja"},{"familyName":"マツヤマ","familyNameLang":"ja-Kana"}],"givenNames":[{"givenName":"Yukihiko","givenNameLang":"en"},{"givenName":"幸彦","givenNameLang":"ja"},{"givenName":"ユキヒコ","givenNameLang":"ja-Kana"}],"nameIdentifiers":[{"nameIdentifier":"630","nameIdentifierScheme":"WEKO"},{"nameIdentifier":"90371971","nameIdentifierScheme":"e-Rad","nameIdentifierURI":"https://kaken.nii.ac.jp/ja/search/?qm=90371971"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_access","date":[{"dateType":"Available","dateValue":"2024-10-02"}],"filename":"fra_k_7_24.pdf","filesize":[{"value":"24.7 MB"}],"format":"application/pdf","licensetype":"license_0","mimetype":"application/pdf","url":{"url":"https://fra.repo.nii.ac.jp/record/2010795/files/fra_k_7_24.pdf"},"version_id":"578e3d9f-1971-43fc-8015-1cf7bf785945"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"Heterocapsa circularisquama; dinoflagellate; red tide; shelfish; environmental factors","subitem_subject_language":"en","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":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"有害渦鞭毛藻Heterocapsa circularisquamaに関する生理生態学的研究(1)","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"有害渦鞭毛藻Heterocapsa circularisquamaに関する生理生態学的研究(1)","subitem_title_language":"ja"},{"subitem_title":"Physiological and ecological studies on harmful dinoflagellate Heterocapsa circularisquama -1 Elucidation of environmental factors underlying the occurrence and development of H. circularisquama Red Tide","subitem_title_language":"en"}]},"item_type_id":"10002","owner":"10","path":["1724311990533"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2024-10-02"},"publish_date":"2024-10-02","publish_status":"0","recid":"2010795","relation_version_is_last":true,"title":["有害渦鞭毛藻Heterocapsa circularisquamaに関する生理生態学的研究(1)"],"weko_creator_id":"10","weko_shared_id":-1},"updated":"2025-03-27T06:58:27.537538+00:00"}