The City of Robert, faced with the massive and recurring invasion of Sargassian algae, decided to set up dams at sea against this phenomenon. A first call for tenders was launched for the installation of six dams at sea. C is the company CUBISYSTEM that was selected for the realisation of these first six dams. Three of the six dams have already been installed. However, it must be noted that these dams are insufficient. Indeed, one factor, the current, shows that it is necessary, on the one hand, to set up additional works to protect other neighborhoods including Four-à-Chaux, Pointe Melon and Pointe-l Ecurie, and on the other hand, to modify the linear of the first dams envisaged. Thus, the Pontaléry dam must be supplemented by a dam protecting the Four-à-Chaux district, that of Cayol Bay by a dam at Pointe-Melon and another at Pointe de l’Ecurie. Two dams were then removed from the initial market and are included in this grant application (Pointe Jean-Claude and Pointe La Rose). Several dams are envisaged taking into account the extent of the coastline and the impacted sites. In addition to the first four made at a previous market, five others must be made in Four-à-Chaux, Pointe de l’Ecurie, Pointe Melon, Pointe la Rose for a total of 3,746 linear meters.