抄録
Mercury dispersed in a coastal area and an ocean causes bioaccumulation in bodies of large fish and shellfish through the food chain. Dynamics of mercury in an actual sea are associated with physical, chemical, and biochemical processes. To develop the numerical model for mercury transport and fate, it is necessary to understand the physical mechanism of the mercury transport at least. In this research, we developed the depth-averaged numerical model of tide and tidal current in the Yatsushiro Sea with a highly resolved curve linear coordinate system. A few characteristics of tide, tidal currents, and transport process in the Yatsushiro Sea were investigated numerically. As a result of this research, it becomes clear that i) the M2 tide in the Yatsushiro Sea is amplified by the Ariake Sea, but the Yatsushiro Sea have the opposite effect on the M2 tide in the Ariake Sea, ii) the diurnal tidal currents is dominant rather than the semi-diurnal one in the sea area around the Minamata, and iii) the substances initially released into the Minamata Bay can spread over the whole area of the Yatsushiro Sea for one month.
