Satellite imagery was used to assess the suspended sediment concentration (SSC) of the plume at the Grijalva river mouth, Gulf of Mexico. The SSC was calculated with the algorithm of Topliss. The algorithm was created for Lansdast 5 MSS. For this study it was validated the results for Landsat 7 ETM+ and Landsat 8 OLI. The depth of the ocean floor was measured using the speedtech sounder. The spectral response was registered with a GER-1500 spectroradiometer (with a measurement range of 296.71-1092.08 nm). The spectral responses were used to determine the size of the suspended particles and to perform the atmospheric correction. Spectral responses indicate that silt size particles predominate near the river mouth, whereas clay overtakes further towards the open sea. The trend in the river when water meets seawater, means an increase of suspended sediment towards the surface due to the lower density of fresh water, and the amount of sediment rises in the open sea. The correlation between the measurements in situ and SSC values produced by the algorithm demonstrates that the operation is suitable to estimate suspended sediments.