JpGU-AGU Joint Meeting 2017

Presentation information

[JJ] Oral

A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG51] [JJ] Coastal Ecosystems - 1. Water Cycle and Land-Ocean Interactions

Wed. May 24, 2017 9:00 AM - 10:30 AM 301A (International Conference Hall 3F)

convener:Jun Shoji(Hiroshima University), Ryo Sugimoto(Faculty of Marine Biosciences, Fukui Prefectural University), Makoto Yamada(Research Institute for Humanity and Nature), Masahiko Fujii(Faculty of Environmental Earth Science), Chairperson:Jun Shoji(Hiroshima University), Chairperson:Ryo Sugimoto(Faculty of Marine Biosciences, Fukui Prefectural University), Chairperson:Makoto Yamada(Research Institute for Humanity and Nature), Chairperson:Masahiko Fujii(Faculty of Environmental Earth Science)

9:30 AM - 9:45 AM

[ACG51-02] Land-sea pathways between snowmelt and fishery production

★Invited papers

*Satoshi Nakada1 (1.Graduate School of Maritime Sciences, Kobe University)

Keywords:Land-sea pathway, Snowmelt runoff, Nutrients, Coastal fishery prodcution

Cultured scallop (Patinopecten yessoensis) is a typical coastal fishery in Funka Bay. The annual spat density of scallop is highly correlated with the snowmelt runoff or accumulated snowfall. We investigated the land-sea pathways in Funka Bay, Japan, a typical semi-enclosed bay during snowmelt period to understand how the snowmelt runoff can improve the spat density or production of scallop larvae associated with ocean primary production, by analyzing hydrological and oceanographical data produced by a land-sea integrated model in conjunction with newly compiled datasets of riverine nutrient concentrations and of the particle tracking simulation. The model successfully estimated the riverine dissolved inorganic nitrogen (DIN) flux that is dominated by the temporal variation of the river runoff rather than that of the riverine DIN concentration. Ocean simulation indicated that the freshwater flux supplied by the snowmelt runoff enhances the clockwise circulation along the coast of the bay. The close relationship between the annual spat density of scallop and the snowmelt runoff associated with high DIN concentrations can be explained as follow; riverine nutrients can increase the biomass of phytoplankton in near-shore seas and improve food availability for scallop spawners, resulting in increased egg production in March to April. Therefore, the nutrient flux from agricultural source areas through the large snowmelt runoff has an important role in larvae production. Land-sea pathways need to be identified to design sustainable and synergetic systems of aquaculture and agriculture for the integrated management of coastal regions.