Abstract
In order to elucidate the origin of dissolved organic matter (DOM) in the coastal area, we determined the concentration of nutrients, dissolved organic carbon (DOC), dissolved monosaccharide, and then measured the three dimensional excitation emission matrix spectrum. Sea water samples were collected on November 1999and 6 June 2000 at the Gokasyo Bay in the Mie Prefecture. On 6 June 2000, the concentrations of nutrients were significantly lower than they were on 17 November 1999. Therefore, phytoplankton activity on 6 June 2000 might be higher than that on 17 November 1999. In contrast, the concentrations of DOC and monosaccharide on 6June 2000 were higher than it was on 17 November 1999.
From the results of the three dimensional excitation emission matrix spectrum, three types of fluorescence maximum peaks (Peak A; Ex./Em.=305-325/400-420 nm, Peak B;Ex./Em.=345-365/450-470 nm, Peak C;Ex./Em.=275-280/345-355nm) were observed in seawater samples. It is believed that the source of peak A and peak B were terrestrial organic matter and that of peak C was biological particulate organic matter.
