著者

渡邊 美如々 木村 将士 碓井 星二 根本 隆夫 外山 太一郎 宮崎 淳一 加納 光樹

出版者

アクオス研究所

雑誌

水生動物 (ISSN:24348643)

巻号頁・発行日

vol.2022, pp.AA2022-16, 2022-08-23 (Released:2022-08-23)

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The fish fauna in the middle and lower reaches of Sakura River flowing into Lake Kasumigaura was investigated with casting nets, hand nets and scoop nets in May, July, and October 2020 and from April to October 2021, and compared with data from previous studies conducted in 1984–1987, 1996–2002 and 2010–2015. A total of 36 fish species in 11 families, including 20 introduced exotic and Japanese species and 16 native species, were collected in 2020–2021. The analyses of long-term changes in presence/absence of fish species from the 1980s to the 2020s demonstrated the disappearance of four threatened species (three native bitterling species and the crucian carp Carassius buergeri subsp. 2) by various artificial environmental changes and a gradual increase in introduced exotic and Japanese species spreading mainly from Lake Kasumigaura.

著者

大森 健策 加納 光樹 碓井 星二 増子 勝男 篠原 現人 都築 隆禎 横井 謙一

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.18-019, (Released:2018-08-20)

参考文献数

64

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Large-scale Japanese lakes support many fish species and abundant fisheries resources. However, long-term changes in the fish fauna of such lakes have not been fully investigated, despite recent significant anthropogenic impacts on associated ecosystems. Accordingly, the extensive native and non-native fish fauna of Lake Kitaura, a typical large inland-sea lake (36 km2) in eastern Japan, was investigated based on specimens collected by the staff of Itako Hydrobiological Station, Ibaraki University from 1977 to 1997, plus data from previous studies conducted since the 1950s. In total, 83 species in 35 families have been recorded from the lake from the 1950s to the present decade. The analyses of long-term changes in fish species data since the 1960s demonstrated a sharp decrease in marine, estuarine and diadromous species due to an estuarine barrage (Hitachi River floodgate) established in 1973, the disappearance of nine red-list species (e.g., threatened and near threatened species) following various artificial environmental changes from the 1960s to 1980s, and an increase in introduced exotic and Japanese species after the 1980s.

著者

碓井 星二 加納 光樹 佐野 光彦

出版者

日本水産學會

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.80, no.5, pp.741-752, 2014

被引用文献数

6

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2009 年と 2010 年の春から夏(4, 6, 8 月)に,茨城県北浦の 2 地点のヨシ帯とそれに隣接する護岸帯で魚類群集の構造を比較した。その結果,種数と総個体数はほとんどの月でヨシ帯の方が多かった。このことから,護岸化によるヨシ帯の消失は,魚類の種多様性や総個体数の減少をもたらし,群集構造を変化させることが明らかとなった。ただし,優占種を種ごとにみると,モツゴ,クルメサヨリ,ヌマチチブなどの 5 種はヨシ帯で,一方,シラウオは護岸帯で多く出現した。護岸化による影響は魚種により異なることもわかった。<br>