Transport of particulate organic matter in the Ishikari River, Japan during spring and summer

Both Δ14C and δ13C were used to study transport behavior of particulate organic matter (POM) in the Ishikari River in Japan. Water samples were collected once a month from April to September in 2004. Positive correlations were found between Δ14C and particulate organic carbon (POC) content and Δ14C and δ13C values for the POM samples from June to September. However during snow-melt, distinctive minimum values were found for POC content, Δ14C and δ13C. These results indicate the POC was supplied from different sources and by different mechanisms during spring snow-melt and summer because of variations in water level and discharge.