Development of a new blue carbon ecosystem model to reveal carbon capture and storage function in urban coastal shallow waters

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K04409
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: Osaka Metropolitan University (2022-2023); Osaka City University (2018-2021)
• Principal Investigator: Sohma Akio 大阪公立大学, 大学院工学研究科, 教授 (80601096)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: 生態系モデル / 炭素隔離 / ブルーカーボン / 炭酸平衡系 / 都市沿岸域 / 浮遊系 / 底生系 / 気候変動

Outline of Final Research Achievements

A mathematical ecosystem model was developed to predict and evaluate the climate change mitigation function of urban coastal areas, based on a series of processes: CO2 gas exchange between the atmosphere, ocean, and sediment; fixation of absorbed dissolved inorganic carbon into organic matter and calcium carbonate through biological production; and sequestration of the fixed carbon in sediment. The model is based on the following processes The model integrates the following mechanisms: (1) suspended-sediment-benthic coupling, (2) food web among zooplankton, phytoplankton, and benthic animals, (3) geobiochemical processes, (4) carbonic acid equilibrium system, and (5) transport processes, and was applied to Tokyo Bay for validation. The model analysis revealed changes in the climate change mitigation function in Tokyo Bay from the present to the future and the factors that contribute to these changes, based on the relationships among biological, chemical, and physical processes.

Free Research Field

数理生態学

Academic Significance and Societal Importance of the Research Achievements

ブルーカーボン研究の多くが、炭素に関する実測値から物質収支あるいは統計手法による観測データ解析で気候変動緩和能を予測・評価するのに対し、本研究にて開発したブルーカーボン生態系モデルは，栄養塩－酸素－生物間の生態系網に加え、炭酸平衡系のメカニズムを導入し，これらについて，現地観測値と整合性を検証したモデルであり，現象の理解と予測精度を大きく進展させたものである。また，本モデルは，生物回復と水質改善の評価・予測機能も可能であり，生物回復，水質改善，気候変動緩和という生態系の持つ３機能を俯瞰的に視座し，沿岸浅海域の管理方針を決定に資するコミュニケーションプラットホームにもなり得る。