Variation in Particulate Organic Matter Accompanying Changes of River Discharge in Ise Bay

Abstract

To elucidate the short-term variation in the distribution and composition of particulate organic mater in the surface water accompanying changes in river discharge, detailed observations were conducted in the northern part of Ise Bay. The results showed the influence of terrestrial organic mater changed in connection with river discharge. During normal discharge, the contribution of terrestrial organic mater to particulate organic carbon (POC) in the bay was negligible. However, in case of high discharge, the contribution increased to 50% at ca. 10km offshore areas from Kiso River mouth. Thought he amount of terrestrial organic mater loads increased the amount of POC decreased around the river mouth due to the flush of phytoplankton. After river discharge, phytoplankton bloomed using plenty of terrestrial nutrients These results suggest that, not the terrestrial mater, but the behavior of phytoplankton is important for the surface distribution of POC in Ise Bay.