Enhanced permafrost warming and increased arctic river discharges have heightened concern about the input of terrigenous matter into Arctic coastal waters. The OCoc-from Ocean Colour to Organic Carbon project (IPY-project 1176), funded by the German Research Foundation (DFG), is an Ocean Colour study joined with the Arctic Coastal Dynamics ACD network and Arctic Circum-polar Coastal Observatory Network ACCO-Net (IPY-project 90).OCoc uses Ocean Colour satellite data for synoptical monitoring of suspended and organic matter fluxes from fluvial and coastal sources.The main study regions are the Lena Delta (Arctic Siberia, Russia) and the Mackenzie Delta (Canada). Ocean Colour MERIS Reduced Resolution (RR)-LIB data are processed towards optical aquatic parameters using Beam-Visat4.2 and the MERIS case2 regional processor for coastal application (C2R). Calculated aquatic parameters are optical coefficients and calculated concentrations of chlorophyll, total suspended matter and coloured dissolved organic matter absorption from the water leaving reflectances.Initial results from German-Russian expeditions at the southeastern Laptev Sea Coast in August 2008 and August 2009 are presented. Initial comparisons with expedition data (Secchi depths, cDOM) show that the MERIS-C2R optical parameters total absorption and the first attenuation depth, Z90, seem adequately to represent true conditions. High attenuation values in the spectral blue wavelength range can serve as tracer for terrigenous input.The synoptic information of Ocean Colour products will provide valuable spatial and dynamical information on Organic Carbon and sediment fluxes from the fluvial and coastal systems into the Arctic coastal waters.