Estuarine Circulation and Associated Material Transport in Shallow Waters around a River Mouth

The estuarine circulation and the material transport associated with that in shallow waters around the mouth of Toyogawa River was studied through the field measurement of currents and chemical analysis of waters, carried out in summer, 2008 and 2009. The estuarine circulation was observed throughout the measurement period. The circulation was driven mainly by the wind and was not strongly correlated with the river discharge. Nutrients released from the bottom sediment under the hypoxic condition of bottom waters are transported by the estuarine circulation into the shallow waters, which may contribute to the primary production around the river mouth.