Elucidating the cause of strange odor production in Lake Ogawarako

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07532
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Kitasato University
• Principal Investigator: Maie Nagamitsu 北里大学, 獣医学部, 講師 (00453514)
• Co-Investigator(Kenkyū-buntansha): 村瀬 潤 名古屋大学, 生命農学研究科, 准教授 (30285241) ; 柿野 亘 北里大学, 獣医学部, 講師 (10623936) ; 丹治 肇 北里大学, 獣医学部, 教授 (50414446)
• Research Collaborator: SHIZUKA Kazunori (地独)青森県産業技術センター, 内水面研究所, 研究員 ; EBINA Hideki 小川原湖漁業協同組合
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 物質循環 / 全窒素 / 全リン / 糸状藍藻類 / 2-MIB / 小川原湖

Outline of Final Research Achievements

We unveiled physical environments of water in Lake Ogawarako, and influence of extreme weather events such as strong wind and typhoons to it. A 22-63% of total nitrogen and 38-79% of total phosphorous were distributed in the water layer from 15 to 21 ｍ, which occupied only 13% of whole lake water. Their percentages significantly changed temporally, as such the layer is considered to be the major source of nitrogen and phosphorous in the upper layer. Lake Ogawarako was divided into 3 sub-region with different phytoplankton composition. Since iron concentration in lake water increased in autumn, when cyanobacteria became dominant, iron could be playing a role in the propagation of filamentous cyanobacteria. We isolated 15 strains of filamentous cyanobacteria, 5 strains of which had 2-MIB synthesis gene.

Free Research Field

生物地球化学