日本地球惑星科学連合2018年大会

講演情報

[JJ] Eveningポスター発表

セッション記号 A (大気水圏科学) » A-OS 海洋科学・海洋環境

[A-OS17] 沿岸域の海洋循環と物質循環

2018年5月21日(月) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:森本 昭彦(愛媛大学)、田中 潔(東京大学)、速水 祐一(佐賀大学、共同)、一見 和彦(香川大学農学部)

[AOS17-P05] 淀川河口域における植物プランクトン由来有機物の生成と大阪湾奥の貧酸素化への影響

*渡部 夏帆1小林 志保1中田 聡史2渕 真輝2浅岡 聡2林 美鶴2 (1.京都大学、2.神戸大学)

キーワード:植物プランクトン由来有機物、貧酸素化、河口域

Supplying excessive organic matter often induces oxygen-depleted water masses in semi-enclosed seas. The concentration of dissolved oxygen (DO) was newly added to an environmental index in the Seto Inland Sea in 2016. It is needed to quantitatively simulate the relationship between the terrestrial load of nitrogen and phosphorous and the extent of oxygen-depleted water masses in the coastal seas. In this study, field observations to investigate production and degradation of organic matter were conducted in the river mouth of Yodo River and the head of Osaka Bay in July, August, September and November in 2017. The results for a spatial change of the concentrations of dissolved inorganic nitrogen and particulate organic nitrogen and carbon suggested that a volume of phytoplankton-derived organic matter was generated in the river mouth of Yodo River and a large part of them spreads to the head of Osaka Bay by estuarine circulation. The results for a decomposition experiment showed that 50 - 60% of organic matter in the water samples taken from the river mouth was mineralized within 20 days, suggesting those components would influence on forming oxygen-depleted water masses in Osaka Bay.