Surveillance zones (ZS) have also been established. It concerns the following towns: Bélus, Biarrotte, Biaudos, Cagnotte, Cauneille, Hastingues, Heugas, Josse, Oeyregave, Orthevielle, Peyrehorade, Rivière-Saas-et-Gourby, Saint-André-de-Seignanx, Saint-Geours-de – Maremne, Saint-Laurent-de-Gosse, Saint-Vincent-de-Tyrosse, Saubrigues, Saubusse, Siest, Tercis-les-Bains.