Fish Fauna in Coastal Area of Kashima Island on Border Zone between Hiroshima Bay and Aki-Nada Sea
| Autor: | Kawai, Yuki, Sakai, Yoichi, Hashimoto, Hiroaki |
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| Jazyk: | japonština |
| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | 広島大学総合博物館研究報告. 5:39-45 |
| ISSN: | 1884-4243 |
| Popis: | 瀬戸内海中西部水域において,近年冬期の海水温の上昇傾向が確認され,水中環境への影響が危惧されている。そこで浅海魚類群集の現況把握を目的に,2011 年9 月から2012 年8 月にかけて,広島湾最南部に位置する鹿島の沿岸2 定点において潜水センサス法による魚類相調査を実施した。総計24 科50 種の魚類を確認した。より南方の水域を主要分布域とする魚種は,イシガキダイ,オヤビッチャ,ゴンズイの3 種のみであった。いずれも高水温期に出現し,冬の低水温期に消失していた。各月の出現魚種数と水温との間には有意な正の相関関係が認められ,9 月に最多の32 種を,2 月に最少の7 種を記録した。他水域における魚類相データと本研究との魚種共通率から,鹿島は温帯水域と高い類似性を有することが確認された。本調査水域においては,現状においても,冬期の水温条件が南方系魚類を含め浅海性魚種の生存に大きな制約的影響を与えていると考えられた。 Within the mid-western zone of the Seto Inland Sea including Hiroshima Bay and Aki-nada Sea, environmental changes such as the recent appearance of tropical/warm temperate fish have been observed. This phenomenon is associated with the warming of the water temperature especially during winter. To obtain basic data on the present conditions of the fish fauna, we conducted a year-long underwater fish census on two shallow water sites around Kashima Island from September 2011 to August 2012. A total of 50 species (24 families) were recorded in our monthly surveys, including three species (Plotosus japonicus, Abudefduf vaigiensis, Oplegnathus punctatus) normally occurring in tropical/warm temperate waters. These three species appeared during the warm water season and subsequently disappeared in winter. We found a positive correlation between the number of fish species and water temperature recorded each month (r = 0.85, p < 0.05). The diversity of fish recorded in the present study was very similar to the diversities of fish in temperate waters. Because of the rapid decrease in species number during winter, we suggest that the low water temperature during winter strongly restricts the number of survivors in the fish community even in the temperate waters of the mid-western area of the Seto Inland Sea. |
| Databáze: | OpenAIRE |
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