Restoration Process of an Estuarine Environment and Evaluation of an Environmental Value in a Salt Marsh and a Tidal Flat Formed by Tsunami Disaster

2016 Fiscal Year Final Research Report

• Project/Area Number: 25249068
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: YOKOYAMA KATSUHIDE 首都大学東京, 都市環境科学研究科, 准教授 (10347271)
• Co-Investigator(Kenkyū-buntansha): 千葉 晋 東京農業大学, 生物産業学部, 教授 (00385501) ; 山本 光夫 東京大学, 学内共同利用施設等, 准教授 (30361512) ; 吉永 郁生 公立鳥取環境大学, 環境学部, 教授 (40230776) ; 中山 耕至 京都大学, (連合)農学研究科(研究院), 助教 (50324661) ; 益田 玲爾 京都大学, 学内共同利用施設等, 准教授 (60324662) ; 河野 益近 京都大学, 工学研究科, 教務職員 (70332723) ; 福島 慶太郎 京都大学, フィールド科学教育研究センター, 研究員 (60549426)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 溶存態有機物 / 鉄 / 汽水域 / 震災湿地 / 震災干潟 / 魚類 / ベントス

Outline of Final Research Achievements

Restoration process of an estuarine environment in a salt-marsh and a tidal flat formed by tsunami disaster of 2011 were investigated in the Kesennuma Bay and Moune Bay.
Dissolved organic matter derived from humic substances was related to the ratio of broad-leaved deciduous forest area and agricultural land area, and the concentration increased during rainfall. Total iron concentration in the surface layer of the sea was related to precipitation around a river mouth.
Both total fish abundance and species richness increased from the first to the second year after the tsunami. Bimonthly survey of larval fishes revealed that unique larval fish community had been established in the newly formed salt-marsh. 21 species of mollusk including the Manila clam were founded in the newly formed tidal flat. This suggests that the restored tidal flat has high potential as fishing ground of the Manila clam if its physical environments get back to a more natural condition.

Free Research Field

環境水理学