The stretch of sea facing the coast of the West part of the Ligurian Sea, with the Tyrrhenian Sea forms the GSA9.
The continental shelf in this area is much reduced, and this leads to an abrupt lowering of the seabed a short distance from the coast. This particular structure, together with factors such as the cold wind coming from the France and the contribution of the current source atlantic, generating in the Ligurian Sea, an area where the surface waters lose quickly heat, becoming more dense.
With the increase of the density of the surface waters are sinking, forcing the deep waters rich in nutrients to the lifts. The contribution of these nutrients triggers the food chain, starting from phytoplankton comes to cetaceans.
It has a great variety of species and a high level of biodiversity, but not on the coast, where the lack of rivers large disadvantage the development of large biomass.
The availability of stock is so limited, but on the other hand, has an excellent quality of the fish for the presence of numerous rare species.