[A-CG35_28PM1] 陸海相互作用－沿岸生態系に果たす水・物質循環の役割－

[ACG35-04] 安定同位体比を利用した淀川河口域における窒素動態解析

*杉本 亮¹、笠井 亮秀² (1.福井県立大学海洋生物資源学部、2.京都大学フィールド科学教育研究センター)

キーワード：窒素, 安定同位体比, 河口循環流, 富栄養化, 再生産

The increase in human population in coastal watersheds has increased the delivery of nitrogen from the land to coastal environments. Accelerated nitrogen cycles in coastal environments have led to an increase in hypoxic waters and instances of harmful algal blooms. Physical and biogeochemical processes within estuaries generally regulate nitrogen fluxes from land to sea. The estuaries of major rivers on the continents are thought to be sites of massive nitrogen losses. However, function of estuaries to nitrogen transfer must vary according to each estuarine hydrology and biogeochemistry. A large amount of terrestrial nitrogen empties into Osaka Bay head from the Yodo River. Although the estuary would have a crucial role in modifying nitrogen fluxes, its function to nitrogen transfer is still unclear. In this presentation, we will report the seasonal difference of nitrogen dynamics along the longitudinal section from the estuary to the head of Osaka Bay.