Surface sediment dynamics along the shore of Hammamet Gulf (Tunisia, southern Mediterranean)

• Sediment dynamics along with grain size and mineral composition.
• Distribution of grain size is linked to inputs by streams and water currents.
• Sediments consist essentially of quartz and calcite.
• Further industrial installations should be avoided.

In the summer of 2015 the authors analysed grain size and surface sediment composition through high spatial resolution from samples taken at 53 stations along the Hammamet coast (southern Mediterranean Sea). The Acoustic Doppler Current Profiler deployed in this study showed that the surface current flows toward the north-east, parallel to the coast at a maximum speed along the main axis of about 5.9 cm s−1. Near the bottom the current flows toward the north-west at a maximum speed of 2.2 cm s−1. The tide plays a relatively small role in water circulation in Hammamet Gulf. Spatial distribution of particle size, along with speed and current direction analysis, furnish an overview of the gulf’s sediment dynamics and transport. The sands are categorised as moderately sorted, well sorted or very well sorted. Particle size distribution of surface sediments from the coast to a depth of 25 m offshore shows a decreasing trend in the offshore direction. Mineralogical analysis shows that Hammamet’s coastal sands are composed of two main minerals: quartz and calcite. Magnesium calcite and aragonite are present in small amounts.Sediment dynamics along the Hammamet Gulf shores are complex, being subject to the effect of swells and secondarily of tides. We encourage the implementation of responsible environmental management procedures in order to help preserve the site.