Influence on material cycle in the East China Sea related to spatial and temporal variation in N/P ratio

2014 Fiscal Year Final Research Report

• Project/Area Number: 25550012
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: Nagoya University
• Principal Investigator: MORIMOTO Akihiko 名古屋大学, 地球水循環研究センター, 准教授 (80301323)
• Co-Investigator(Kenkyū-buntansha): YAMADA Machiko 福岡女子大学, 文理学部, 教授 (30438303) ; UEDA Hiroshi 高知大学, 総合科学系, 教授 (00128472) ; TAKIKAWA Tetsutaro 独立行政法人水産大学校, 海洋生産管理学科, 准教授 (10371741)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 窒素リン比 / 東シナ海 / 日本海 / 長江希釈水 / 対馬暖流 / 低次生態系モデル

Outline of Final Research Achievements

Enormous sea water including fresh water originated from Chang Jiang River in the East China Sea are transported to the Japan Sea by the Tsushima Warm Current. Ratio between nitrogen and phosphate (N/P ratio) in sea water varies during transport process. We have investigated how the N/P ration variability influence material cycle in the East China and Japan Seas by hydrographic observation and numerical experiment. We found from hydrographic observation that dominant phytoplankton and zooplankton correspond to characteristics of water mass, and phytoplankton and zooplankton consist of 2 group and 3 group, respectively. We have developed a lower trophic ecosystem model and carried out experiments by different condition of N/P ratio. From the numerical experiments, it was found that only large phytoplankton increased when N/P ratio became high.

Free Research Field

沿岸海洋学