Nile Delta



ID

524

Author(s)

Emily. Peck and Michele Thieme, Conservation Science Program, WWF-US, Washington, DC, USA


Countries

Egypt

Reviewer(s)

M. S. Farid, Water Resources Research Institute, Cairo, Egypt and S. Baha El Din, Cairo, Egypt


Major Habitat Type

large river deltas

Drainages flowing into

Mediterranean Sea


Main rivers to other water bodies

The Nile River previously braided into numerous channels as it flowed through the delta, moving and depositing unconsolidated, alluvial sediment from the upper reaches of the river to the complex of lagoons, marshes, lakes, temporary pools, agricultural lands and shallow coastal areas along the Mediterranean Sea. Since the construction of the Aswan High Dam (completed in 1970), water flow through the delta has dramatically decreased and its floodplains are no longer subject to annual flooding. As a result, the Nile River now occupies only two main channels - the Rosetta (western) and the Damietta (eastern). Today several small lakes occupy former river channels such as El Mannah, El Qatta, Faraonyat, Sinnéra and San El Hagar. The main wetlands in the delta are the coastal Lakes of Manzala, Burullus, Idku and Lake Maryut.



Description

Boundaries

The Nile Delta is a fertile fluvial triangle wedged in the midst of one of the driest deserts in the world. Situated in northern Egypt, the Delta extends about 175 km from its apex at Cairo to the Mediterranean Sea, and is about 260 km wide along the coast (Hughes & Hughes 1992). This ecoregion is defined by the extent of the delta and associated marshes.

Freshwater habitats

All deltas, including the Nile, experience phases of growth and shrinkage, as a result of sediment input and redistribution by rivers and coastal processes. During the last 7,000 years the Nile Delta has generally been in the accretion phase. However, in the last 150 years the delta has entered an acute stage of subsidence, catalyzed by the construction of dams and barrages along the upper and lower Nile, and the intensive regulation of the Nile’s waters (Stanley and Warne 1998). The outer margins of the delta are eroding and salinity levels of some of the coastal lands are rising as a result of seawater infiltration to the ground water (Hughes & Hughes 1992; Baha El Din 1999). At the same time the brackish Lakes Manzala, Burullus, and Idku have decreasing salinity levels due to relatively high year-round inflows of freshwater and poor connections with the Mediterranean ((Ramdani et al. 2001).

Changes in the aquatic vegetation of the delta reflect changes in the Nile’s flow and sediment distribution. The Cyperus papyrus swamps that previously existed in the wettest areas of the delta disappeared with the closure of the Aswan High Dam. Reeds Phragmites australis and Typha sp. are now common throughout the delta wetlands, along with some species of sedge Juncus sp. (Hughes & Hughes 1992). Ceratophyllum covers many of the delta lakes where water is fresh or slightly brackish. In lacustrine areas of higher salinity Potamogeton pectinatus and P. crispus predominate (Burgis & Symoens 1987).

Terrestrial habitats

Away from the lakes and swamps most of the Nile Delta is intensively cultivated. Only remnant patches of Mediterranean coastal vegetation remain, mainly on coastal sand dunes. Although the agricultural landscape is dominated by non-native species, some native plants, including several locally rare species, such as Pistia stratiotes and Nymphaea lotus, manage to persist along canals, drains, and roads.Two endemic plant species are found: Sonchus macrocarpus (endemic to the Nile Delta) and Zygophyllum aegyptium (restricted to Egypt and Libya). There are few globally threatened plant species.

Description of endemic fishes

The Delta supports no endemic fish, but there is one endemic mollusk (Biomphalaria alexandrina).

Justification for delineation

This ecoregion is delineated based on the extent of the Nile Delta and its marshes and is distinguished by a Nilo-Sudanian freshwater fauna with some brackish and marine elements.


References

  • Baha El Din, S. M. (1999). "Directory of Important Bird Areas in Egypt" Cairo, Egypt: Palm Press.
  • Baha El Din, S. M. (2001). "Egypt" Fishpool, L. D. C.;Evans, M. I. ( (Vol. Important bird areas in Africa and associated islands: Priority sites for conservation, pp. Pisces Publications and Birdlife International ) 241-264.
  • Burgis, M. J.;Symoens, J. J. (1987). "African wetlands and shallow water bodies" Paris, France: ORSTOM.
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  • Hughes, R. H.;Hughes, J. S. (1992). "A directory of African wetlands" Gland, Switzerland, Nairobi, Kenya, and Cambridge, UK: IUCN, UNEP, and WCMC.
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  • Ramdani, M., Flower, R. J., Elkhiati, N., et al. (2001). "North African wetland lakes: Characterization of nine sites included in the CASSARINA project" Aquatic Ecology 35 (3-4) pp. 281-302.
  • Wetlands International (2002) \Ramsar Sites Database: A directory of wetlands of international importance\ "<"http://ramsar.wetlands.org/">" (2003)
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