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Location Mauritania, Trarza
Central coordinates 16o 26.00' West  16o 34.00' North
IBA criteria A1, A4i, A4iii
Area 15,500 ha
Altitude 2 - 6m
Year of IBA assessment 2001

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.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Northern Shoveler Spatula clypeata winter  2001  4,590 individuals  A4i  Least Concern 
Greater Flamingo Phoenicopterus roseus winter  2001  1,543 individuals  A4i  Least Concern 
Lesser Flamingo Phoeniconaias minor resident  present  A1  Near Threatened 
Pied Avocet Recurvirostra avosetta winter  2001  5,650 individuals  A4i  Least Concern 
Black-tailed Godwit Limosa limosa winter  2001  7,900 individuals  A4i  Near Threatened 
Slender-billed Gull Larus genei winter  2001  800 individuals  A4i  Least Concern 
Caspian Tern Hydroprogne caspia winter  2000  986 individuals  A4i  Least Concern 
A4iii Species group - waterbirds winter  2001  20,000 individuals  unknown  A4iii   

IBA Monitoring

2001 high not assessed not assessed
Good - based on reliable and complete / representative data

Biological resource use fishing & harvesting aquatic resources - unintentional effects: large scale likely in short term (within 4 years) majority/most of area/population (50-90%) moderate to rapid deterioration high
Biological resource use hunting & collecting terrestrial animals - intentional use (species being assessed is the target) happening now some of area/population (10-49%) slow but significant deterioration medium
Pollution agricultural & forestry effluents - herbicides and pesticides happening now majority/most of area/population (50-90%) slow but significant deterioration high
Pollution agricultural & forestry effluents - nutrient loads happening now majority/most of area/population (50-90%) moderate to rapid deterioration high
Pollution domestic & urban waste water - type unknown/unrecorded happening now some of area/population (10-49%) slow but significant deterioration medium
Residential and commercial development commercial and industrial development happening now some of area/population (10-49%) moderate to rapid deterioration high

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Chat Tboul Wetlands of International Importance (Ramsar) 15,500 is identical to site 15,500  


IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial   9%
Rocky areas   49%
Grassland   38%
Desert   2%

Land use

Land-use Extent (% of site)
agriculture -
fisheries/aquaculture -
hunting -
nature conservation and research -
tourism/recreation -
water management -
other -
Notes: Local salt collection.

References De Naurois (1969), Hamerlynck and ould Samba (1995), IUCN (1999), Measson (2001).

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Chott Boul. Downloaded from on 27/10/2016

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