The Behavior of dissolved organic matter (DOM) in the Kuji estuary, Ibaraki

Sakamoto, Ai; Tanaka, Takayuki; Otosaka, Shigeyoshi  

In this study, to resolve the behavior of DOM and the generation mechanism of the refractory DOM in the Kuji estuary, Ibaraki, we address the temporal variations of some different factors affecting estuarine DOM flux at both the field observation and the quasi-field observation. The seasonal change of DOC concentration ranged from 1.0 0.1 mgC/L (average s.d. (this "s.d." means daily variation)) in December 2009 to 1.9 0.2 mgC/L in June 2010. From the results of the quasi-field observation, we showed the amount of change on DOC concentration concerned with each variable factor (x) as delta-DOCx. Applying these results of quasi-field observation to the field one, we found that the variation of DOC concentration was greatly governed by not only the phytoplankton biological effect but also the physical effect which indirectly led, such as the elution from the sediment resuspention. These contribution ratio of each variation for the time-series were more than 50%.