Particulate　organic　matter　(POM)　in　the　coastal　zone　plays　an　important　role　in　global　carbon　cycle,　yet　its　spectral　properties　under　human　disturbance　are　not　well　understood.　This　study　investigated　the　source　and　dynamics　of　POM　in　a　typical　coastal　area　(Minjiang　Estuary,　China)　under　the　influences　of　estuarine　mixing,　urbanization　and　dam　construction,　based　on　spectral　and　isotopic　analysis.　The　yield　of　particulate　organic　carbon　from　the　watershed　(0.38　g　m−　2　yr−　1)　was　in　part　limited　by　the　historical　decrease　in　sediment　discharge　downstream　hydropower　station.　The　absorption　and　fluorescence　indices　of　POM　suggested　an　important　contribution　from　biological　production　with　a　low　humic　content.　The　importance　of　river　and　estuarine　production　was　supported　by　elemental　and　isotopic　analysis,　in　particular　for　N-bound　constituents　of　POM.　Three　humic-like　and　two　protein-like　fluorescent　components　were　identified　from　POM　using　fluorescence　excitation-emission　matrices-parallel　factor　analysis　(EEMs-PARAFAC).　They　showed　weak　correlations　with　salinity,　suggesting　non-conservative　behaviors　of　fluorescent　POM　during　the　estuarine　mixing.　Principal　component　analysis　(PCA)　identified　two　principal　factors,　which　were　related　to　the　level　of　chromophoric　POM　(PC1)　and　biological　production　(PC2),　respectively.　The　PCA　results　indicated　stronger　influence　of　biological　production　in　the　estuarine　zone　and　potential　effect　of　sediment　re-suspension　and/or　wastewater　discharge　in　the　urban　zone.　Overall,　our　results　demonstrated　significant　influences　of　human　disturbance　on　the　flux,　source　and　dynamics　of　POM　in　the　coastal　zone,　which　could　be　assessed　by　spectral　and　stable　isotopic　analysis.　©　2019　Elsevier　B.V.