The causes of the erosion of the coastline are many, well-known and almost always correlated. The coastline, on the one hand, have suffered from natural phenomena (like eustasy and subsidence, or sea storms), on the other hand from the unintended result of interventions carried out by men in the past (like the construction of the "murazzi" and of the outer jetties, or the use of the territory and its irreplaceable resources).
The rivers, for example, once transported considerable quantities of sand and silt to the sea where they were then distributed by currents along the beach. Today, this process has been considerably reduced, among others, by the rigid channelling of river flow and by the construction of hydroelectric basins. Furthermore, sand from the existing beaches is continually carried away by the combined action of sea storms and tides. Also the human presence on the littorals has contributed to their deterioration. It is enough to consider the camp sites built near the dunes, or the overcrowding of beaches during the summer and motorcycles and cars driving over the dunes.