Ionian Sea

The Ionian Sea is a regional sea of the Mediterranean Sea between southern Italy and the western coasts of Albania and Greece. It is connected to the Adriatic Sea through the Strait of Otranto and to the Tyrrhenian Sea through the Strait of Messina. The sea lies between the southern Italian Peninsula and the southern Balkans and contains the Ionian Islands.

Geography

The western side of the Ionian Sea is bordered by eastern Sicily, Calabria, and the Salento Peninsula in southern Italy. Calabria lies between the Ionian Sea to the east and the Tyrrhenian Sea to the west. The northeastern coast follows southern Albania from the area around Vlorë to the Greek border. South of Vlorë, the Albanian coastline becomes narrower and more mountainous as it faces the Ionian Sea.

The eastern shore includes western mainland Greece and the western coast of the Peloponnese. The Greek islands within the sea include Corfu, Paxos, Lefkada, Ithaca, Kefalonia, and Zakynthos. These islands form most of the Ionian Islands group and extend along the western coast of Greece.

The Strait of Otranto forms the northern entrance to the sea between southeastern Italy and Albania. The Strait of Messina passes between Sicily and Calabria and connects the Ionian Sea with the Tyrrhenian Sea. To the south, the Ionian basin opens into the central Mediterranean.

Major coastal inlets include the Gulf of Taranto and Gulf of Squillace in Italy, and the Ambracian Gulf, Gulf of Patras, Gulf of Kyparissia, Messenian Gulf, and Laconian Gulf in Greece. The Gulf of Patras provides access to the Gulf of Corinth through the Strait of Rion.

The southern Ionian Sea contains the Calypso Deep, the deepest known point of the Mediterranean Sea, at approximately 5,122 metres below sea level. It lies within the Hellenic Trench southwest of the Peloponnese. The surrounding area is tectonically active because of movement between the African and Eurasian plates.

The coastal environment includes deep offshore basins, narrow continental shelves, rocky shores, beaches, bays, wetlands, and island channels. Marine habitats support fish, marine mammals, seabirds, seagrass meadows, and other Mediterranean species. Coastal development, fishing, shipping, marine pollution, and rising water temperatures affect parts of the sea.

History and maritime use

The Ionian Sea has served as a route between the Italian Peninsula, the Balkans, and the Greek world since antiquity. Greek settlements developed along the coasts of southern Italy and Sicily, where many became part of Magna Graecia. Maritime routes connected these settlements with mainland Greece and the islands.

After Roman expansion, the sea formed part of the transport system linking Italy with Epirus, Greece, and the eastern provinces of the Roman Empire. Ports and crossings supported military movement, administration, commerce, and communication across the central and eastern Mediterranean.

During the medieval and early modern periods, the Ionian Sea remained an important route for the Byzantine Empire, southern Italian states, the Republic of Venice, and the Ottoman Empire. Control of ports, islands, and narrow passages affected trade and naval movement between Italy and the southern Balkans.

The sea continues to support commercial shipping, fishing, passenger transport, and tourism. Major ports on or near its coasts include Taranto, Catania, Syracuse, Messina, Corfu, Igoumenitsa, and Patras. Ferry and cargo routes cross the northern Ionian Sea between Italy, Albania, the Greek mainland, and the Ionian Islands.

See also

• Mediterranean Sea
• Adriatic Sea
• Tyrrhenian Sea
• Strait of Otranto
• Strait of Messina
• Ionian Islands
• Southern Europe