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Location Mauritania, Brakna
Central coordinates 15o 10.00' West  16o 45.00' North
IBA criteria A4i, A4iii
Area 16,500 ha
Altitude
Year of IBA assessment 2001





Site description Rkîz is situated approximately 90 km north-east of the town of Rosso. It is a depression 34 km long and 4–6 km wide aligned north-east–south-west. It is filled by water from the Senegal river and, to a lesser extent, from run-off due to rainfall. Two swamps, the Nasio and the Laouwaya, join Rkîz to the river system. The eastern part of the lake is 3 m below sea-level and the western 2 m below. The lake has dried out completely in drought years. The construction of a dam in the Laouwaya, as well as a dyke at Nasio, has limited the natural filling of the lake and reduced the area of the lake to 6,100 ha. The whole area is now managed by a system of dams and dykes for the cultivation of rice.

The transformation of the lake into an agricultural zone has led to the loss of most of the original vegetation. The northern part of the lake remains the most species-rich. It is dominated by Cassia tora, with Nymphaea sp., Mimosa pigra, Indigofera oblongifolia, Echinochloa pyramidalis and Aeschynomene sp. The banks are typically covered with grasses such as Cynodon dactylon, Dactyloctenium and Eragrostis spp. Elsewhere, remaining trees include Acacia raddiana and A. senegal as well as Leptadenia pyrotechnica. Following clearance for agriculture Calotropis procera has colonized much of the area and is now the dominant ligneous species. In the south-west there are some saline soils with Tamarix senegalensis. In the south-east, where the oueds lead to Nasio and Laouwaya, some stands of Acacia nilotica still persist, due to seasonal flooding via the rice-fields.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Northern Pintail Anas acuta winter  1975  10,000 individuals  A4i  Least Concern 
Garganey Spatula querquedula winter  1999  27,800 individuals  A4i  Least Concern 
Purple Swamphen Porphyrio porphyrio winter  2000  206 individuals  A4i  Least Concern 
A4iii Species group - waterbirds winter  20,000-49,999 individuals  unknown  A4iii   

Habitats

IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial   40%
Grassland   59%

Land use

Land-use Extent (% of site)
agriculture -
forestry -
water management -
other -
Notes: Firewood collection.

Other biodiversity Crocodylus niloticus and Hippopotamus amphibius are reported to be present in the area; both are nationally threatened.

References Roux (1976), van Wetten (1989).

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Rkîz. Downloaded from http://www.birdlife.org on 28/08/2014

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