Balkan Rivers & Streams - A Global Ecoregion
Distinctive European fish and mollusk fauna
Snapshot: Ecoregion 180
Size:
225,000 sq. km (90,000 sq. miles)
Habitat type:
Small Rivers
Geographic Location:
Southeastern Europe: Albania, Bosnia and Herzegovnia, Bulgaria, Croatia, Greece, Italy, Macedonia, Serbia, Slovenia, Turkey, and Yugoslavia
Conservation Status:
Critical/Endangered
Quiz Time!
Where else in the world can one find karst topography?
Answer:
The United States, China, Mexico, and Croatia all have large areas of limestone and karst terrain. In these places, land above the ground is barren and rocky, but deep rivers and lakes lie below. Some of these rivers and lakes have eroded through the limestone and created caves and stone bridges.
Answer:
The United States, China, Mexico, and Croatia all have large areas of limestone and karst terrain. In these places, land above the ground is barren and rocky, but deep rivers and lakes lie below. Some of these rivers and lakes have eroded through the limestone and created caves and stone bridges.
About the Area
Much of southern Europe escaped glaciation thousands of years ago and hence diversity within water bodies tends to be higher here, than in northern Europe. In addition, the soft limestone that the Balkans are built of, allow water that seeps underground to create subterranean karst channels where many aquatic species live.
The Balkans region hosts an extremely diverse and highly endemic (both at a local and regional level) gastropod fauna (snail species), with about 200 known species. For example, the Sava River alone harbours 103 species, of which 54 are endemic. Many endemic fish species and genera are also present in the ecoregion.Local Species
Restricted mainly to the Dalmatian karst area of Bosnia-Herzegovina, the highly endangered Dalmatian barbel gudgeon (Aulopyge hügeli) inhabits both above-the-ground rivers and subterranean karst rivers.
Subterranean watercourses in the ecoregion also support populations of the highly endangered and endemic Olm, or blind salamander (Proteus anguinus), as well as many endemic invertebrates.
Endemic trout live in the rivers and lakes of this ecoregion, including Ohrid (Salmo letnica), Marbled (Salmo marmoratus), and Belushka (Acantholingua ohridana) trouts, as well as S. dentex.
The ecoregion is home to a number of other endemic and rare fishes, many of which are vulnerable, endangered, or even critically endangered. Among these species are Greek brook lamprey (Eudontomyzon hellenicus), Leuciscus illyricus, and Phoxinellus ghetaldii.
Threats
The aftermath of recent conflicts in this region includes large-scale movements of refugees across the region and pollution and fires originating from bombed industrial sources. Other threats comprise agricultural and industrial waste, untreated sewage effluents, and construction of dams.
The ecoregion also includes a large number of introduced species that are believed to have negatively impacted native species. For example, hybridisation of the rare Marbled trout (Salmo marmoratus) with the introduced Brown trout (S. trutta) has reduced the genetic integrity of the native species.
Resources
• NationalGeographic.com
