Sites - Important Bird and Biodiversity Areas (IBAs)
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16o 26.00' West 16o 34.00' North
A1, A4i, A4iii
2 - 6m
Year of IBA assessment
Site description Chott Boul is a coastal wetland formed by an ancient mouth of the Senegal river, now isolated from it and with only temporary connections to the sea (behind a 10-km strip of coastal dunes). It lies 175 km south of Nouakchott and 70 km west of Rosso. The total area is approximately 15,500 ha, of which 7,000 ha is a marine zone of mudflats, intertidal saltmarsh, fresh water and brackish zones. The terrestrial zone is made up of 8,500 ha of wetland, floodable plains with temporary and permanent swamps, lakes and marshes of brackish to hyper-saline water. Fresh water enters the system between September and November from Hassi Baba swamp, part of the Diawling-Tichillit system within Diawling National Park (site MR021). Thus, the southern edge of Chott Boul is contiguous with Diawling while Aftout-Es-Saheli (MR012) lies immediately to the north and is fed by a swamp connecting the Grand Lac at Chott Boul with the southern flood-plain of the Aftout.
Other than for this swamp, Chott Boul is limited to the north by mobile and stable dunes and to the east by a flood-plain and rice-fields. The dunes to the north are covered by Euphorbia balsamifera and Tamarix senegalensis. The northern part of the site is an unvegetated, flat saltpan, which may once have been an area of mangroves. The south is characterized by halophytic vegetation, the remnants of flood-plain forests (Acacia nilotica, Tamarix senegalensis) and grasslands (Sporobolus robustus, Vetiveria nigritana and Juncus rigidus).
Key Biodiversity See Box for key species. In addition, Chott Boul is one of the only sites where Podiceps nigricollis overwinters in the area; 180 were recorded in December 1998. Counts of other species include 4,000 Larus fuscus in 2001. Chott Boul and the southern parts of Aftout es Saheli hold only known nesting colony of Phoenicopterus minor in West Africa (see site MR012).
Non-bird biodiversity: The canids Fennecus zerda (DD) and Vulpes pallida (DD) occur, as does the nationally vulnerable Varanus griseus.