The Sea of Marmara: The Small Sea Linking the Black and Aegean Seas

The Sea of Marmara is an inland sea entirely within Turkey, serving as the crucial aquatic bridge between the Black Sea and the Aegean Sea (part of the Mediterranean). It connects via two strategic straits:

• The Bosphorus Strait (northeast) – Links to the Black Sea; separates European and Asian Istanbul.
• The Dardanelles Strait (southwest) – Links to the Aegean Sea; historic gateway to the Mediterranean.

Covering 11,350 km² (4,380 sq mi), the Sea of Marmara is relatively small but geopolitically immense. Its waters are two-layered: a surface layer of lower-salinity Black Sea outflow, and a deep layer of saltier Mediterranean inflow. This stratification affects fisheries, pollution dispersion, and maritime traffic.

Major cities on its shores include Istanbul (spanning both continents), İzmit, Bandırma, and Tekirdağ. The sea has been a crossroads of civilizations—Greek, Roman, Byzantine, Ottoman—and remains a vital commercial corridor for Russian and Ukrainian grain, oil, and global shipping.