Boundaries

This ecoregion spans the junction of Europe and Asia in northwestern Anatolian Turkey, European Turkey, and eastern Greece. The ecoregion is bounded by the Balkan Mountains in the north, Struma River watershed in the west, Aegean Sea and Sea of Marmara to the south, and the Anatolian Plateau to the east. Its neighbors include the Northern Anatolia [430] ecoregion to the east, Western Anatolia [429] to the south, Vardar [422] to the west, and Dniester-Lower Danube [418] to the north.

Topography

Extensive plains surround the Sea of Marmara. The upper reaches of rivers rise from major mountain ranges, such as the Balkan, Rila, and Rhodope mountains in the north and west, and Anatolian Plateau in the east. Elevations range from sea level to over 2780 m.

Freshwater habitats

Rivers have fairly gentle gradients on the Asian shore. The lower reaches can be marshy.

Terrestrial habitats

Low and relatively even land surrounds the Sea of Marmara in contrast to other fringes of the Anatolian Plateau. The landcover includes mixed forest with irrigated and dry farming and tree crops.

Description of endemic fishes

There are no endemic genera, and only six endemic species, including Macedonia shad (Alosa macedonica), A. vistonica, Barbatula bureschi, Cobitis puncticulata, C. punctilineata, and Gobio bulgaricus.

Other noteworthy fishes

Up to six species of sturgeons, now highly endangered, historically used the waters of this basin for reproduction. These include the Russian sturgeon (Acipenser gueldenstaedtii), Fringebarbel sturgeon (A. nudiventris), starlet (A. ruthenus), starry sturgeon (A. stellatus), sturgeon (A. sturio), and beluga (Huso huso).

Ecological phenomena

This basin has an extensive marine coastline. The lower reaches of rivers, and some lakes, have a fauna derived from the sea that is not seen in more inland basins. The sturgeons have been noted above, but several other marine origin families migrate into fresh water for feeding and reproduction.

Justification for delineation

The diversity and species composition separates this fauna from those of neighboring basins. Lakes Uluabat and Manyas are Ramsar Sites. Sturgeons, shads, and kilkas, the cyprinodont Aphanius fasciatus, the balitorid Barbatula bureschi, and the cyprinids Barbus cyclolepis and Petroleuciscus borysthenicus are in the Red Data Book.

Level of taxonomic exploration

Good