Sea of Marmara about 22 parts per thousand, which is slightly greater than that of the Black Sea, but only about two-thirds that of most oceans. The water is much more saline at the sea bottom, averaging salinities of around 38 parts per thousand, similar to that of the Mediterranean Sea. This high-density saline water, like that of the Black Sea, does not migrate to the surface. Water from the Susurluk, Biga (Granicus) and Gonen Rivers also reduces the salinity of the sea, though with less influence than on the Black Sea. With little land in Thrace draining southward, almost all of these
Ligurian Sea part. The sea receives the Arno River from the east and many other rivers that originate in the Apennines. The ports of Genoa, La Spezia, and Livorno are on its rocky coast. It reaches a maximum depth of more than northwest of Corsica. The International Hydrographic Organization defines the limits of the Ligurian Sea as follows: "On the Southwest." A line joining Cape Corse (Cape Grosso, 9°23′E) the Northern point of Corsica to the frontier between France and Italy (7°31′E). "On the Southeast." A line joining Cape Corse with Tinetto Island () and thence through Tino and Palmaria Islands to