Effects of land-based pollution control on coastal hypoxia: a numerical case study of integrated coastal area and river basin management in Ise Bay, Japan

Integrated Coastal Area and River basin Management (ICARM) is important to maintain/improve the sustainability of the coastal ecosystem services. We describe the effects of the land-based pollution reduction on the water quality in Ise Bay, Japan, based on the numerical simulations. The numerical model for water and material flow-flux in the bay consists of the hydrodynamic and the pelagic-benthic ecosystem models. The hydrodynamic model could predict the 3D current, pressure, salinity, and temperature. The pelagic-benthic ecosystem model simulated the available evaluation for the C-N-P-O biogeochemical cycle. The numerical simulations were carried out in order to investigate the response of coastal hypoxia in Ise Bay to the pollutant loading reductions predicted by the river basin model under the various social scenarios. These simulated results indicated that hypoxia volume could be reduced to 67% of the present loading condition if the most effective control of the point and nonpoint sources was adopted