The Stagnone di Marsala is a 20 km2 extensive (about 1.8 km wide by 11 km long) lagoon on the North-western coast of Sicily (Italy). The lagoon has a northern narrow and shallow mouth to the sea (400 m wide, 0.3-0.4 m deep) and another wider and deeper to the south (1200 m wide, 1.0-1.5 m deep). At the eastern end of the northern opening a 20 m wide, 1 m deep channel was dredged, somehow enhancing the local flushing capability. Inside the lagoon, beside the islands of Motia and Santa Maria, there is a slightly submerged relict Phoenician road, which is effective in reducing flow, thus creating a low-flushing sub-basin to the North-East,