IUCN Management Category Proposed I (Strict Nature Reserve)

Biogeographical Province 3.12.07 (Western Sahel)

Geographical Location Delta of River Senegal. 16°26'N, 16°21'W.

Date and History of Establishment To be gazetted. Establishment of reserves is in the hands of the Ministry of Rural Development.

Area 13,000ha

Land Tenure Government

Altitude Near sea level

Physical Features The Senegal delta is one of the major wetlands of Sahelian Africa and provides a staging point and wintering area for many birds that breed in Eurasia. It consists of a vast basin of impermeable halomorphic soils forming saline flats, which are subject to annual flooding. The development of various dyke systems over the last 20 years on the Senegalese bank of the river has allowed the retention of water in some areas of the basin longer than they would normally have persisted, whilst in other areas the effect has been to desiccate the fragile soils and enhance desertification. Salinity varies with water level from nearly fresh during autumn inundations, to brackish as the water levels fall. The climate is Sahelian with alternate wet and dry seasons. Mean annual rainfall is 300mm and mean annual temperature 27°C. The reserve receives fresh water from distributaries of the River Senegal from August to November. During the dry season, the basin is the wettest area in the region, but recent rainfalls have been very low, and the reserve, which usually begins to dry out in January, has not retained its moisture for as long.

Climate No information

Vegetation The vegetation reflects the three habitat types found in the lower delta: dunes, alluvial plains and an interconnecting network of rivers, lakes and pools. Tree cover on the dunes comprises Acacia tortilis, A. senegal, Euphorbia balsamifera, and Balanites aegyptiaca. Herbaceous cover comprises Cenchrus biflorus, Chloris prieurii and Schoenefeldia gracilis, amongst others. Towards the edge of the dunes, tree cover is more varied and abundant, with Borassus aethiopum, Acacia nilotica, A. seyal, and some Parkinsonia aculeata. There is little tree cover on the alluvial plain, but Tamarix senegalensis and Arthrocnemum glaucum occur on sandy knolls and Acacia nilotica beside creeks and pools. Herbaceous cover on the lower zones of the plain is dominated by halophiles, with Salsola baryosma being replaced by Sporobolus robustus in the most frequently flooded areas. Grasses are more important in less saline areas, with Echinochloa colonum or Vetiveria nigritana in depressions, and Schoenefeldia gracilis on higher ground. Tree cover is well developed on the network of rivers and pools, with Tamarix senegalensis and dense stands of Arthrocnemum glaucum. The reed Paspalum vaginatum is found along river banks. There is a 5ha mangrove swamp mainly composed of Avicennia nitida, but with some specimens of Rhizophora racemosa. All of the vegetation has been significantly affected by drought and overgrazing, and trees have been cropped for firewood. Sand dunes are beginning to form in areas where grass has failed to regenerate. The mangrove swamp is receding owing to the incursion of sand and some felling.

Fauna The lower delta of the River Senegal is an important collecting and breeding ground for waterfowl. Together with the Senegalese part of the delta, where the Parc National des Oiseaux du Djoudj is situated, this area provides an important feeding and watering site for numerous Palearctic migrants. Fewer birds breed or gather on the Mauritanian part of the delta, owing to a poorer supply of fresh water, but it provides feeding grounds for birds breeding on the opposite bank. In this respect, the proposed nature reserve will be an important complement to Djoudj which has insufficient feeding grounds. The mangrove swamp supports breeding colonies of purple heron Ardea purpurea, night heron Nycticorax nycticorax, african spoonbill Platalea alba, cormorant Phalacrocorax carbo, and white pelican Pelecanus onocrotalus. Away from the water, small numbers of bustards (Otidae), guinea fowl Guttera sp., and francolins Francolinus sp. are present. The warthog Phacochoerus aethiopicus is the predominant mammal, with jackal Canis sp. and smaller carnivores also found. Elephant Loxodonta africana, hippopotamus Hippopotamus amphibius, gazelles Gazella sp., and the larger carnivores are no longer present. The brackish water, where the river water meets the sea, provides an important breeding ground for fish such as Ethmalosa fimbriata, bass Dicentrarchus punctatus, the mullets Mugil curema and Liza falcipinnis, and for marine crustacea such as prawn Penaeus duorarum and blue crab Callinectes sp.. These provide an important source of food for the breeding birds. The West African manatee Trichechus senegalensis and the Nile crocodile Crocodylus niloticus have almost disappeared, both being formerly abundant.

Cultural Heritage No information

Local Human Population No information

Visitors and Visitor Facilities Restricted access

Scientific Research and Facilities No information

No information

Conservation Value No information

Conservation Management Total protection recommended

No information

The Mauritanian government is well aware of the conservation interest of its delta wetlands and a proposal includes the creation of an artificial estuary to maintain the highly productive mixing of fresh and salt waters, a process condemned to end once the Diama dam (see below) is finished. An area has been earmarked for reserve creation and the Mauritanian government has requested help in equipping the protected zone. The Ministry of Rural Development, with the help of a resident FAO wildlife expert, is drawing up plans for this reserve and a series of others, including the creation of an international protected area. This would incorporate Diaouling Reserve, Djoudj National Park in Senegal, and the area between the right and left banks of the Diama dam. It is recommended that Diaouling reserve employs a permanent conservator who is trained in wildlife management and who would be in charge of controlling public access, permit distribution, poaching and forest exploitation, prohibiting pastoralism and human activity, and providing guided tours for visitors (Prévost, 1983).

Management Constraints The area has undergone considerable ecological modification because of hydro-agricultural development over the last 20 years, which has had the effect of intensifying agriculture in some areas whilst causing desiccation, deforestation, overgrazing, and desertification in others. This process has been aggravated by the droughts which have struck this region in the last 15 years. The governments of the surrounding countries regard dams as the solution to the problems of supplying food and water to the human population. The Senegalese bank of the river has been subject to damming since the 1960s to control the annual flood and to permit irrigation and agricultural development, notably rice and sugar cane, but the Mauritanian bank so far remains relatively untouched. The major threat now comes from the constrution of the Diama dam 30km upstream of St Louis, due to be completed by about 1986, which would affect both banks of the river. It will block the river completely, preventing the summer incursion of saltwater. Low water levels due to lack of rain in recent years have affected breeding birds. White pelicans abandoned breeding in 1983 because of this. Less moisture has also meant that dunes have become destabilised and even blocked river channels.

Staff Conservator, deputy conservator, three wardens, and a driver are recommended.

Budget Some Mauritanian funds available for Mauritanian personnel and part of running cost. Outside finance is necessary for equipment and training. A Budget of US$50,000 sought from WWF.

Local Addresses

No information

References

Gee, J.P. (1984). Birds of Mauritania. Malimbus 6: 31-66.

IUCN/WWF Project 3404. Mauritania, Establishment of Diawling Reserve.

Prévost, Y. (1983). Avant-Projet de Plan d'Aménagement de la Réserve du Diawling. Projet MAU/80/503, Etude sur la Faune, FAO, Nouakchott.

Date October 1984