Parque Natural da Ria Formosa

 

On the continental margin of the lagoon, where we are, dunes are not frequent and when they occur they are poorly developed. This results in that in these sheltered waters sediment transport is reduced. We have a very different situation in the 50 km long barrier island cord between Ancão and Manta Rota, which delimits the lagoon. The action of wind, currents and tides annually drag hundreds of thousands of tons of sand and unceasingly change the outline of the islands. Let us not forget that we are going through a period of rising sea levels, when the barrier islands tend to retreat towards the continent. This natural phenomenon is reinforced by human interventions on the coast: construction of marinas and ports, installation of spurs. Construction (often clandestine), trampling and vehicle traffic (on the peninsulas) by destroying the dune vegetation facilitate erosion.