Study to elucidate obstructive factor against recovery of submerged plants and to design sustainable use of aquatic ecosystem after the recovery of submerged plants

2014 Fiscal Year Final Research Report

• Project/Area Number: 24310053
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Environmental technology/Environmental materials
• Research Institution: The University of Tokyo
• Principal Investigator: YAMAMURO Masumi 東京大学, 新領域創成科学研究科, 教授 (80344208)
• Co-Investigator(Renkei-kenkyūsha): FUJII Shinji 人間環境大学, 人間環境学部, 准教授 (40228945) ; MOMOHARA Arata 千葉大学, 大学院園芸学研究科, 准教授 (00250150) ; HAYASHI Norio 千葉県立中央博物館生態, 環境研究部生態学研究科, 上席研究員 (60250156)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ヨシ / アサザ / 水質浄化 / 自然再生 / 沈水植物 / 除草剤 / アメリカザリガニ / 富栄養化

Outline of Final Research Achievements

Submerged aquatic plants disappeared during late 1950’s in the lakes in plains in Japan, and they have not been recovered yet in most of the lakes. The cause of the decline is attributed to eutrophication and shore protection work, and reeds and fringed water-lilies are planted to decrease COD of lake water. We hypothesized herbicide and red swamp crayfish are suppressing the recovery of the submerged aquatic plants. At the experiment ponds with predators of the crayfish, submerged plants could survive till the intrusion of herbicides. The comparison of water quality before and after the intrusion of submerged plants in Lake Shinji revealed they don’t have ability to purify water. Incubation experiments showed that plantation of reeds ad fringed water-lilies would increase the COD of the lakes.

Free Research Field

水圏環境学