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Location Mauritania, Brakna
Central coordinates 13o 59.00' West  17o 6.00' North
IBA criteria A1, A4i, A4iii
Area 4,275 ha
Altitude 30 m
Year of IBA assessment 2001

Site description Lac d’Aleg is situated 5 km to the north-west of the town of Aleg in the south-west of the country. The lake is a closed depression in an old course of the Senegal river fed by rainwater run-off from Oued Katchi, which drains a catchment of 3,420 km². The Katchi is a seasonal watercourse which was formerly a tributary of the Senegal river, but now cut off from it by dunes. The lake is endorheic and semi-permanent and typically varies in depth from 1–2 m at the end of the dry season to a maximum of 3–4 m at the end of the rains. At its maximum size, usually attained in October, it is 22 km long and 4 km wide. The area of the lake varies considerably from year to year depending on rainfall. The vegetetation of the lake forms concentric rings in which the central zone is characterized by Echinochloa stagnina, Nymphaea lotus, N. oleracea, Ipomoea aquatica and Aeschynomene pfundii. Nearer the water’s edge Sesbania rostata, Ammania senegalensis, Cynodon dactylon and Cyperus erectus dominate, while in seasonally inundated areas Bergia suffructicosa, Alternanthera sessilisa and Glinus lotoides are common. The banks are characterized by woody species such as Balanites aegyptiaca and Capparis decidua and grasses include Cenchrus biflorus, Cyperus conglomeratus and Dactyloctenium aegyptiacum. The southern edge of the lake is bounded by the Nouakchott–Aleg road. Average annual rainfall is c.150 mm.

Key Biodiversity See Box for key species. In addition, there are occasional records of Falco naumanni, Gallinago media, Glareola nordmanni and Acrocephalus paludicola from this site. All are thought to refer to birds on passage, although the status of A. paludicola is hard to establish. More than 116,000 waterbirds were recorded here in September 1987. Merops bulocki, a species of the Sudan–Guinea Savanna biome (A04), has been recorded at this site.

Non-bird biodiversity: None known to BirdLife International.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Northern Pintail Anas acuta winter  1987  33,000 individuals  A4i  Least Concern 
Fulvous Whistling-duck Dendrocygna bicolor winter  1987  9,000 individuals  A4i  Least Concern 
Spur-winged Goose Plectropterus gambensis winter  1987  5,000 individuals  A4i  Least Concern 
Garganey Spatula querquedula winter  1996  50,350 individuals  A4i  Least Concern 
Ferruginous Duck Aythya nyroca winter  1999  120 individuals  A1, A4i  Near Threatened 
Glossy Ibis Plegadis falcinellus winter  2000  2,380 individuals  A4i  Least Concern 
Purple Swamphen Porphyrio porphyrio winter  1999  760 individuals  A4i  Least Concern 
Himantopus himantopus winter  1996  1,613 individuals  A4i  Not Recognised 
Caspian Tern Hydroprogne caspia winter  2000  335 individuals  A4i  Least Concern 
A4iii Species group - waterbirds winter  100,000-499,999 individuals  unknown  A4iii   


IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial   28%
Shrubland   14%
Grassland   56%

Land use

Land-use Extent (% of site)
agriculture -
hunting -
urban/industrial/transport -
water management -

References Eleyou (1990), Paloc (1960), van Wetten et al. (1990), Yésou and Triplet (1996).

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Lac d'Aleg. Downloaded from on 26/10/2016

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