Study on the environmental influence of the construction of the Giant Sea Wall in Jakarta Bay

• Project/Area Number: 16H05626
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Environmental impact assessment
• Research Institution: Saga University
• Principal Investigator: Hayami Yuichi 佐賀大学, 農学部, 准教授 (00335887)
• Co-Investigator(Kenkyū-buntansha): 佐藤 慎一 静岡大学, 理学部, 教授 (70332525) ; 森本 昭彦 愛媛大学, 沿岸環境科学研究センター, 教授 (80301323) ; 吉野 健児 佐賀大学, 低平地沿岸海域研究センター, 特任助教 (40380290) ; 濱田 孝治 佐賀大学, 低平地沿岸海域研究センター, 准教授 (30294979)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥16,510,000 (Direct Cost: ¥12,700,000、Indirect Cost: ¥3,810,000); Fiscal Year 2019: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2018: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2017: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2016: ¥7,280,000 (Direct Cost: ¥5,600,000、Indirect Cost: ¥1,680,000)
• Keywords: 海洋環境 / 大規模開発 / 貧酸素水塊 / ジャカルタ湾 / インドネシア / 環境影響評価 / 海外調査 / 貧酸素 / ベントス / 沿岸開発

Outline of Final Research Achievements

A hypoxic water mass was formed in the Jakarta Bay almost throughout a year mainly in the south eastern area. The recovery of hypoxia was generated by the cold intrusion from out of the bay mouth. The oxygen demand of bottom water and bottom sediment was high which was equivalent to the Tokyo Bay and Hiroshima Bay. As the Jakarta Bay was located in the equatorial area, no continuous vertical convection occurred in a year. Therefore, the density stratification generated by the river water continued throughout a year. The persistent hypoxic water mass was generated since a lot of sewage water containing high concentration of nutrients flowing into this system. The macrobenthos abundance in the southeastern area was very low. It suggested that the persistent formation of hypoxic water mass inhibited the survival of benthos.

Academic Significance and Societal Importance of the Research Achievements

ジャカルタ湾ではしばしば魚類の大量斃死が起きており、貧酸素水塊の影響ではないかと指摘されてきたが、これまでは観測データが少なく、検証されていなかった。本研究の結果、ジャカルタ湾ではほぼ年間を通して貧酸素水塊が形成されていることが初めて分かった。また、赤道域ではこのような継続的な貧酸素水塊が形成されやすいことを世界で初めて指摘した。今後、ジャカルタ湾の開発を進めるにあたってはこのような貧酸素化の状況を考慮することが重要である。
本研究の結果は、今後のジャカルタ湾の適切な環境管理、環境再生を進めるための基盤的な材料を提供するものである。また、本研究はインドネシア研究者の研究技術向上にも寄与している。

Research Products

• [Int'l Joint Research] BPPT(インドネシア)
• [Int'l Joint Research] 科学技術評価応用庁（BPPT）(インドネシア)
• [Int'l Joint Research] 科学技術評価応用庁（BPPT）(インドネシア)
• [Int'l Joint Research] 科学技術評価応用庁（BPPT）(インドネシア)
• [Journal Article] Occurrence of the Indo-West Pacific echiuran Listriolobus brevirostris (Annelida: Echiura) in Jakarta Bay, Indonesia, likely due to human-mediated introduction (2019)
  • Author(s): Teruaki Nishikawa, Shin'ichi Sato, Yuichi Hayami, Suhendar I Sachoemar and Agus Sudaryanto
  • Journal Title: Biogeography Volume: 21 Pages: 48-50
  • NAID: 130007896254
  • Peer Reviewed / Int'l Joint Research
• [Presentation] The environmental study to understand the hypoxia behavior in Jakarta Bay (2019)
  • Author(s): Suhendar I SACHOEMAR et al.
  • Organizer: International symposium on coastal ecosystem change in Asia: hypoxia, eutrophication, and nutrient conditions
  • Int'l Joint Research
• [Presentation] Behavior and residence time of river waters in Jakarta Bay (2019)
  • Author(s): Endro SOEYANTO et al.
  • Organizer: International symposium on coastal ecosystem change in Asia: hypoxia, eutrophication, and nutrient conditions
  • Int'l Joint Research
• [Presentation] The Dead zone in Jakarta Bay (2018)
  • Author(s): Yuichi Hayami, Akihiko Morimoto, Agus Sudaryanto, Suhendar I. Sachoemar, Endro Soeyanto, Alfi Rusdiansyah, Mochamad Saleh and Shinichi Sato
  • Organizer: EMECS 12
  • Int'l Joint Research
• [Presentation] Observation of the hypoxic water mass in Jakarta Bay (2018)
  • Author(s): Yuichi Hayami, Akihiko Morimoto, Agus Sudaryanto, Suhendar I. Sachoemar, Endro Soeyanto, Mochamad Saleh, Kenji Yoshino, Shinichi Sato and Shota Oda
  • Organizer: Second CCore-RENSEA Seminar on Coastal Ecosystems in Southeast Asia
  • Int'l Joint Research
• [Presentation] インドネシア・ジャカルタ湾における貧酸素水塊 (2017)
  • Author(s): 速水祐一・森本昭彦・Agus Sudaryanto・Suhendar Sachoemar・Endro Soeyanto・Mochamad Saleh・織田将太
  • Organizer: JpGU-AGU Joint Meeting 2017
• [Funded Workshop] The 1st Joint Workshop on Marine Environment of Jakarta Bay: Scientific Networking for Environmental Studies (2018)