Inter-annual variability of wet season freshwater plume extent into the Great Barrier Reef lagoon based on satellite coastal ocean colour observations

► CDOM is a useful surrogate for salinity in Great Barrier Reef coastal waters. ► Satellite remote sensing is a cost effective method for large scale mapping of CDOM. ► The freshwater extent was successfully estimated for the entire GBR region. ► Remotely sensed freshwater extent is significantly correlated with river discharge. ► Low salinity waters were found to reach a number of inner and mid-shelf reefs.