This paper reports data on the dissolved and colloidal organic carbon in the Zhujiang (Pearl) River estuary. DOC concentration was 142 to 239 μmol/L in the freshwater taken in March 1997 from the four Zhujiang River tributaries flowing into the Lingdingyang estuary. High concentration was observed in the Humen tributary located near Guangzhou. The rapidly increased DOC concentration at low salinities (～5) may be attributed to the exchange between macroparticulate and dissolved organic matter during the earl...ThisworkwassupportedbyEuropeanCommissionundercontractCI1 -CT94 -0 1 3
