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Ecoregion Description


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Species Richness


# of Endemic Species


Threats

438: Jordan River

Major Habitat Type:

xeric freshwaters and endorheic (closed) basins

Author:

Brian Coad

Countries:

Egypt; Israel; Jordan; Lebanon; Occupied by Israel; Syria; West Bank

Boundaries:

The ecoregion encompasses the drainage basin of the Jordan River. It is bounded by the Coastal Levant ecoregion [436] to the west, Arabian Interior ecoregion [440] to the east, and Sinai ecoregion [435] to the south.

Drainages flowing into:

Dead Sea

Main rivers or other water bodies:

The main river is the Jordan, which originates in the Anti-Lebanon Mountains in Syria. It connects the Sea of Galilee (Lake Kinneret or Tiberias) to the Dead Sea, but is actually little more than a stream. Wadis – valleys with intermittent watercourses – that flow into the Jordan include Wadi Mujib, Wadi Mousa, Wadi Hassa, and Wadi Zarqa.

Topography:

This ecoregion lies along the Jordan Valley, a narrow rift valley with mountains to the east and west reaching over 2500 m. It forms part of the Great Rift Valley, which extends from southern Turkey down through East Africa.

The Jordan River flows into the Dead Sea, which lies at the lowest point on earth’s surface (402 m below sea level).

Climate:

The northwestern part of the ecoregion experiences a Mediterranean climate, with hot, dry summers and cool, wet winters. This changes to steppe and then desert as one moves east and south. The ecoregion’s mean annual temperature is roughly 19 ºC, with minimum temperatures ranging between -3 and 10 ºC, and maximum temperatures ranging between 22 and 40 ºC. Mean annual precipitation is 240 mm.

Freshwater habitats:

The flow of the Jordan River has been greatly reduced, and its salinity increased due to the diversion of water resources for agricultural uses. Lake Hula has been completely drained. Lake Kinneret is a fresh, warm monomictic lake with a high mineral content. The Dead Sea, which is landlocked and fed by the Jordan River and run-off from side wadis, is hypersaline and fishless. Springs, however, harbor fishes; some are saline oasis springs.

Terrestrial Habitats:

Much of the ecoregion is a semi-desert environment with large irrigated agricultural tracts. It is subdivided into three separate biomes: Mediterranean forests, woodlands, and scrub; temperate greasslands, savannas, and shrublands; and xeric shrublands and desert. Higher elevations support oak and pine forests. Olive, eucalyptus, and cedar are common in the highlands and valley. Shrubs occur throughout the ecoregion.

Fish Fauna:

The ecoregion contains around 25 species in six families, of which cyprinids and cichlids are dominant.

Description of endemic fishes:

Nearly a third of the species in the ecoregion are endemic and fall into the Cyprinidae (Acanthobrama hulensis, Acanthobrama lissneri, Garra ghorensis, Pseudophoxinus drusensis), Balitoridae (Nemacheilus insignis, Nun galilaeus), and Cichlidae (Astatotilapia flaviijosephi, Tristramella sacra) families. The only endemic genus is Nun in Balitoridae. Mirogrex species are more generally placed in the wider ranging genus Acanthobrama. Acanthobrama hulensis from the former Lake Hula is extinct (IUCN 2009).

Other noteworthy fishes:

The North African catfish (Clarias gariepinus) is found here and in the Levant, but is not in the Tigris-Euphrates drainage basin.

Other noteworthy aquatic biotic elements:

The ecoregion contains Tethyan relicts, including blind prawns, subterranean mollusks, and endemic sponges (Por & Dimentman 1989). The Dead Sea has halo-resistant and halo-obligatory species of algae and bacteria.

Ecological phenomena:

Mass appearances of dinoflagellates occur in Lake Kinneret. Exotics are affecting the ecology of the remaining marshes in the Hula Nature Reserve.

Evolutionary phenomena:

The complex history of this basin and its connections to neighboring basins, Africa, and the Tigris-Euphrates basin, as well as its Tethyan links, are reviewed in Por and Dimentman (1989).

Justification for delineation:

This ecoregion is distinguished by its endemics, Tethyan relicts, and the varied (for Southwest Asia) cichlid fauna of African origin. The Hula Nature Reserve is a Ramsar site.

Level of taxonomic exploration:

Good

References/sources:

Krupp, F.,Schneider, W. (1989). "The fishes of the Jordan River Drainage Basin and Azraq Oasis" Fauna of Saudi Arabia 10 347-416.

Por, F. D.,Dimentman, C. (1989). "The Legacy of Tethys: an aquatic biogeography of the Levant" 63 Dordrecht: Kluwer Academic Publishers.

Scott, D. A. (Ed.) (1995). "A Directory of Wetlands in the Middle East" Gland, Switzerland and Slimbridge, U.K: IUCN and International Waterfowl and Wetlands Research Bureau.

Serruya, C.,Pollingher, U. (1983). "Lakes of the warm belt" Cambridge: Cambridge University Press.

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