Sediment dynamics have been studied from 1979 to 1984 by the use of radio active tracers, to quantify sediment transport and to know the limits of tides and swell action in terms of sediment composition and depth. This technique has allowed the study of sand drifting (between -2 m and -15 m) and resuspension of muddy sediments. The effects of sediment movements on estuarine sediment accumulation are included in this report.