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タイトルヨミ
コスイ カンキョウ ノ ジンイテキ カイゾウ ト テイセイ ユウコウチュウ ノ グンシュウ ヘンカ ソノ3 ナカウミ トウブ ノ カコ スウジュウネン ノ カンキョウ ヘンカ
日本語以外のタイトル
Benthic Foraminiferal Changes in Relation to Human Activities in Brackish Environment(Part 3) : Environmental Hanges During the Past Several Decades in eastern Lake Nakaumi
ファイル
言語
日本語
著者
野村 律夫
山根 幸夫
内容記述(抄録等)
We report the benthic foraminiferal changes with respect to human activities in brackish environment over several decades. During the past several decades, many reclaimed areas have appeared in the eastern part of Lake Nakaumi, in addition to the dredging of bottom sediments and the construction of a gate for water exchange. The bottom water and foraminiferal fauna might have been influenced directly and indirectly by these human activities .
 The most critical foraminiferal changes were found in the sediments of 60-70 years ago (-1920-30) and in those of 25 years ago (early 1970). We belive the first faunal event was caused by the dredging of sediments in Sakai Strait, which caused salty marine and brackish waters to be exchanged. A 2.8km long embankment constructed in the mouth of Sakai Strait might have facilitated the introduction of marine water into Lake Nakaumi. By this process, Trochammina hadai increased in place of the previously developed Ammonia beccarii fauna in the deeper part of the lake. The second faunal changes might have caused by further introduction of salty water into the main lake area by limiting the opening to Nakaura Gate.
 We attribute the foraminiferal changes to the formation of more stabilized halocline by a consistent input of marine water and the subsequent development of reduced bottom environment.
主題
bottom environment
foraminifera
human activity
Lake Nakaumi
salinity changes
掲載誌名
Laguna : 汽水域研究
3
開始ページ
13
終了ページ
24
ISSN
21852995
発行日
1996-03
NCID
AN10439529
出版者
島根大学汽水域研究センター
資料タイプ
紀要論文
ファイル形式
PDF
著者版/出版社版
出版社版
部局
研究・学術情報本部 エスチュアリー研究センター
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