Effect of oxygenation of coastal hypoxia on sediment microbial community composition and activity

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K23685
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0603:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: MORI Fumiaki 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(高知コア研究所), 特別研究員(PD) (60849537)
• Project Period (FY): 2019-08-30 – 2022-03-31
• Keywords: 貧酸素水塊 / 化学合成独立栄養細菌 / 堆積物 / 大村湾 / 閉鎖性内湾

Outline of Final Research Achievements

We evaluated the effects of temporal oxygen supply to coastal hypoxia on oxygen consumption processes and microbial community structure in the surface layer of sediments. When sediments were exposed to oxygen saturated sea water, the sediment oxygen consumption process was mainly driven by aerobic respiration of microorganisms, which accounted for about 75% of the total oxygen consumption of anoxic sediment core. In addition, significant growth of chemolithoautotrophic bacteria with sulfur oxidation function was observed. These results suggest that the temporal supply of oxygen to hypoxia may stimulate the high sediment oxygen consumption derived from aerobic respiration of chemolithoautotrophic bacteria and contribute to the reformation of hypoxia.

Free Research Field

微生物生態学

Academic Significance and Societal Importance of the Research Achievements

本研究で明らかになった貧酸素海域への一時的な酸素供給時における堆積物酸素消費速度および微生物群集構造の変化は、沿岸域で頻発する貧酸素水塊が改善されない原因の一部を明らかにする成果である。今後、これらのプロセスを海洋生態系モデルに取り入れていくことにより、将来の地球環境変動に対する沿岸生態系の応答について、予測精度を向上させることが期待できる。