Japan Geoscience Union Meeting 2014

Presentation information

Oral

Symbol A (Atmospheric, Ocean, and Environmental Sciences) » A-CG Complex & General

[A-CG35_28PM1] Land-Ocean Interaction -Water and material cycle for coastal ecosystems-

Mon. Apr 28, 2014 2:15 PM - 4:00 PM 421 (4F)

Convener:*Makoto Yamada(Research Institute for Humanity and Nature), Makoto Taniguchi(Research Institute for Humanity and Nature), Ryo Sugimoto(Faculty of Marine Biosciences, Fukui Prefectural University), Masahiko Ono(National Institute of Advanced Science and Technology), Chair:Makoto Yamada(Research Institute for Humanity and Nature), Masahiko Ono(National Institute of Advanced Science and Technology)

3:10 PM - 3:25 PM

[ACG35-04] Evaluation of nitrogen dynamics in the Yodo River estuary using stable isotopes

*Ryo SUGIMOTO1, Akihide KASAI2 (1.Faculty of Marine Biosciences, Fukui Prefectural University, 2.Field Science Education and Research Center, Kyoto University)

Keywords:nitrogen, stable isotopes, estuarine circulation, eutrophication, regeneration

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.