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DJOUDJ NATIONAL BIRD SANCTUARY, SENEGAL
Brief description: In the Senegal River delta, the Djoudj
Sanctuary is a wetland of 16,000 hectares, a large seasonally flooded area
of lakes, ponds and bayous surrounded by streams and backwaters, which form
a living but fragile sanctuary for three million migrant birds and a large
breeding population, including white pelican, purple heron, African spoonbill,
great egret and cormorant.
Threats to the Site: Since 1999 the Sanctuary has been
threatened by the rapid invasion of a water plant, Salvinia molesta, which
had also reached Diawling National Park in Mauritania across the river.
This is one of the most invasive plants in the world and threatens the ecosystem
and economy of the region. Use in 2001 of biological control by plant-eating
weevils from South Africa, began to clear the weed but may need annual reapplication.
The national authorities agreed to inscription on the List to facilitate
a three year task of eradication and help their appeal for financial support
from donors.
COUNTRY Senegal
NAME Djoudj National Bird Sanctuary (Parc
National des Oiseaux du Djoudj)
IUCN MANAGEMENT CATEGORY
II National Park. Ramsar site.
Natural World Heritage Site, inscribed in 1981. Natural
Criteria iii, iv
Listed in Danger in 1984-8 and in 2000 because of the effect of dams and
invasion by rampant waterweeds.
BIOGEOGRAPHICAL PROVINCE Western Sahel (3.12.07)
GEOGRAPHICAL LOCATION In the extreme northwest
of the country on the Mauritanian border, in the delta of the Senegal
River about 60km north-northeast of Saint-Louis. In a wide low valley
10 km north of Ross-Bethio: 16°30'N, 16°10'W.
DATE AND HISTORY OF ESTABLISHMENT
| 1962: |
A nearby
area of 3ha was first classified a nature reserve by Decree No.62-065
in 1962; |
| 1971: |
Designated
a national bird sanctuary by Decree No.71-411 (13,000ha); |
| 1975: |
Enlarged
by Decree No.75-1222 to 16,000ha; |
| 1977: |
Designated
a Wetland of International Importance under the Ramsar Convention. |
| 2000: |
Placed
on the list of World Heritage in danger because of a destructive invasion
by waterweed |
AREA 16,000ha; adjoining Diawling National Park,
Mauritania (13,000ha: created 1991, Ramsar,1994).
LAND TENURE Government, in Region du Fleuve
province. Managed by the National Parks Service of the Ministry for the
Protection of Nature.
ALTITUDE From near sea-level to about 20m.
PHYSICAL FEATURES The Sanctuary is a small part
of the wide delta floodplain of the Senegal river, the second largest
river in west Africa, which marks the line between the Sahara and the
Sahel and forms an important ecological barrier on the desert edge. A
third of the wetland is in Mauritania. The Sanctuary is in the basin of
the brackish Djoudj bayou (distributary or marigot) between the
main river channel to the north and the Gorom bayou to the south. It is
an area of three related habitats: bayous, meres and backwaters dry for
three months every year, usually flooded basins (cuvettes) and
irregularly flooded alluvial plains. During the dry season it is the only
naturally green spot along the whole river. The ground is covered with
impermeable salt-impregnated alluvial clays forming saline flats. It was
originally steppe, paddy-fields, marshes and lagoons subject to annual
flooding from September. But dykes have canalised the river and an anti-saltwater
barrier built downstream now keeps fresh water in the basin for long periods,
replacing the former balance of wet and dry, fresh and saltwater cycles.
CLIMATE This is a semi-arid Sahelian climate
with alternate wet and dry seasons, tempered by the ocean and sea winds.
The mean annual rainfall, between July and mid-September, never exceeds
300mm, but during the dry months (March to June), it is the most humid
area in the region. There is 40% dry season and 70% wet season humidity.
Flood levels are highest in October, but in recent years rainfall has
been less than a fifth of the average and Djoudj has become much drier.
The mean annual temperature is 27°C, but during the cold season between
December and March the temperature can fall to 10°C.
VEGETATION The vegetation is a mosaic of Sahelian
habitats, the product of low rainfall on halomorphic soils. The savanna
is dominated by spiny bushes, acacias such as Acacia nilotica (which
needs seasonal flooding) A.tortilis, A.seyal, Balanites
aegyptiaca, Tamarix senegalensis and Euphorbia balsamifera.
Herbs include Mimosa pigra, Echinochloa colonum
and Aeschynomene spp.; grasses include Oryza longistemma, Echinochloa
stagnina and Vossia cuspidata. Halophytic plants, particularly
Salicornia spp., cover much of the area. During the rains and
because a barrier dam has prevented salt water from moving upstream, dense
reedmace Typha australis and waterlily Nymphaea spp.
now grow in the flood zones and, in the shelter of this, aquatic vegetation
became dominated first by Pistia stratoites and since 1999, by
Salvinia molesta, a rank freshwater invader, to levels which have
become dangerous to other life (Triplet et al., 2000).
FAUNAFor millions of Palaearctic ducks and other aquatic birds,
the Sanctuary, along with the Niger swamps in Mali and Lake Chad, is one
of the great staging and wintering areas on the far side of the Sahara.
From September to April, an estimated three million migrants pass through,
joining a dense population of resident breeding birds. Between 450-550,000
Anatidae, 250,000 Limicolae, 20,000 greater flamingos Phoenicopterus
ruber, 3,000-12,000 lesser flamingos P. minor and 2,500 European
spoonbills Platalea leucorodia, owe their winter survival to the
quality of the environment of the Senegal river delta (Triplet et al.,2000).
300 species have been recorded including garganey Anas querquedula,
shoveler A. clypeata, pintail A. acuta, ruff Philomachus
pugnax, and black-tailed godwit Limosa limosa. About 5,000
white pelican Pelecanus onocrotalus nest here regularly, as well
as pinkbacked pelican Pelecanus rufescens, common cormorant
Phalacrocorax carbo, white-breasted cormorant P. lucidus, African
darter Anhinga rufa, night heron Nycticorax nycticorax,
squacco herons Ardeola spp., green heron Butorides striatus,
various egrets Egretta spp., purple heron Ardea purpurea,
grey heron Ardea cinerea, yellowbilled stork Mycteria ibis,
sacred ibis Threskiornis aethiopicus, glossy ibis Plegardis
falcinellus, African spoonbill Platalea alba, white-faced
tree duck Dendrocygna viduata, fulvus tree duck D. bicolor,
spur-winged goose Plectropterus gambensis, and Sudan bustard Otis
arabs.
Other animals include warthog Phacochoerus aethiopicus, jackal
Canis aureus, and African manatee Trichechus senegalensis
(V). Red-fronted and dorcas gazelles Gazella rubifrons and G.dorcas
and the Nile crocodile crocodylus niloticus have been successfully
reintroduced. There are also python Python sebae and monitor lizards,
Varanus spp.
CULTURAL HERITAGE No information is available.
LOCAL HUMAN POPULATION The local Wolof and Halpulaar,
Haratin and Sarakolé farmers have developed ways of using the local
resources subtly adjusted to the very varying regime of flooding and drought:
fishing, mixed farming, rice-growing and grazing cattle on the dry season
pastures. There are also transhumant herders, Moors from Mauritania and
Pleuh from inland who move in as the wet season ends, with whom there
is conflict if drought forces them to stay too long in the floodplain
(van den Top,1990).
VISITORS AND VISITOR FACILITIES More than 5,000
tourists visited the park each year in the 1990s. One camp is open from
mid-November to mid-April and there are hotels in St Louis nearby. A second
has been planned on the north-east border. There are a dozen bird observation
points on the borders of the most important waterbodies. Canoes can be
hired. A small eco-museum has been constructed by the St Louis Club Jeunes-Nature.
SCIENTIFIC RESEARCH AND FACILITIES Research
includes rodent studies, bird ringing to investigate migration routes,
and population dynamics. L’Office de la Recherche Scientifique et
Technique d’Outremer (ORSTOM) has sponsored research in this area
since 1955. Studies of waders were carried out in 1983-1984 by the Station
Biologique de la Tour du Valat, France. An expedition to catch and ring
palaearctic migrants was undertaken in 1990, for which some 3,300 birds
of over 70 species were ringed (Beecroft, 1991). There is an observation
hut on site. A biological research station was established in St. Louis
in 1990 for the area’s parks.
CONSERVATION VALUE The park was mainly established
as an important area for the protection, study and viewing of birds. It
supports three million waterfowl and as one of the first fresh water sources
they reach after crossing 200km of the Sahara, is one of the main West
African sanctuaries for Palaearctic migrants.
CONSERVATION MANAGEMENT In 1991 IUCN and WWF
financed a plan for the Sanctuary to cover the management of water, habitats
for important species, relations with local people, tourism and education
in conserving the area. Water supply in the region is a problem, and permanent
dams have been built to regulate the flow of the Senegal River, including
a dam in Mali. With the completion of the Diama anti-salinity barrage
downriver, the water supply for Djoudj is now much more secure than at
any time in the past except in a small undyked area. A dyke was built
around the park and a system of dams has been maintained to counter the
effects of the Diama barrage, also of the large hydroelectricity and irrigation
Manantali dam upstream in Mali so that water levels would not be affected
by alterations in the flow of the river, or by intensive upstream cultivation
which could increase levels of herbicide and pesticide residues in the
water. Effective management depends on the continued reinforcement of
dykes, repair of water-control structures and dredging of silted canals
(Triplet et al.,2000). Until 1987 rigid protection was enforced. Since
then there has been a policy of cooperating with local villagers whose
numbers are growing, allowing them to use the varied resources of the
site in the way they know best (van den Top,1990). The park is closed
three months of the year for park management. Wardens are stationed in
five watch posts, one in the centre and four on the boundaries. Administration
zones are co-ordinated by a ranger.
MANAGEMENT CONSTRAINTS Rainfall has been too
low in the past few years for water levels to be normal. The Compagnie
Sucrière Sénégalaise built a temporary dam just upstream at Kheune to
prevent salt water flowing up the Senegal River in the dry season which
reduced the supply of fresh water to Djoudj but the 1984 flood swept it
away and Djoudj was replenished normally. In the 1984/1985 dry season,
Djoudj was connected by canal with fresh water above the Kheune barrage
to stop it drying out. However, because of corrosion of one of the two
sluice gates into the park, staff were unable to control water levels
which were largely determined by the Diama reservoir levels (Dugan, pers.comm.,1987).
Pelican nesting sites were threatened, so substitute islets were successfully
built for the birds' use. Djoudj was placed on the World Heritage in Danger
list between 1984 and 1988 because of the alteration in water levels by
these dams. However, habitats at Djoudj are adapted to this threat (Thorsell
1985). But secondary threats to the Sanctuary remain: tree-felling, overgrazing
and poaching, which have all been heavy in the past.
The construction of the Diama dam for irrigation and drinking water had
the effect of drying out the downstream floodplain, estuary and mangroves
and created ideal conditions upstream for invasive freshwater weeds: reed
mace Typha australis, which still forms very dense barriers,
water lettuce Pistia stratiodes, since reduced, and the major
current danger, a south Brazilian water weed Salvinia molesta
which originated from imported chickenfeed. This can double its area every
four days, and becomes a floating mat which chokes all other life, making
fishing and river transport almost impossible. It forms a substrate for
other invasive weeds, exhausts the river's oxygen and increases the habitat
for disease-bearing snails and mosquitoes. It became such a threat to
the riverine ecology and the local economy that the site was again listed
in danger in 2000. Very costly measures were taken to eradicate it, first
mechanical, and then, successfully, by the concentrated use of biological
control by the weevil Cyrtobagus salviniae (Triplet et al.,2000;
Pieterse,2002). The WHB, IUCN, Ramsar Secretariat and FAO all collaborated
with the State in the program of eradication which could become a model
for Africa (UNESCO,2002).
STAFF A total of 21 rangers and one conservator
(National Park Office, pers. comm.,1995).
BUDGET 3 million francs CFA* (National Park
Office, 1995). In 2000 the WHB conditionally approved US$ 130,475 to finance
Phase I of the Salvinia eradication campaign; and in 2001, US$21,690 for
a regional workshop in methods of inventorying wetlands (UNESCO,2001).
* franc du Communauté Financiere Africaine
LOCAL ADDRESSES
Conservateur, Parc National des Oiseaux de Djoudj, BP
80, Saint Louis, Senegal
REFERENCES
Anon. (n.d.). Unpublished Country and National Parks. Report received
1988. 32 pp.
Beecroft, R.(1991). Ringing in Senegal; an expedition update. The
British Trust for Ornithology (Mar/April) 173: 5.
Bientema, A. (1990) Management of the Djoudj National Park. In Marchand,
M. & Udo de Haes, H. Proceedings of the International Conference
on Wetlands. The People's Role in Wetland Management. Centre for Environmental
Studies, Leiden,The Netherlands.
CNPPA Summary Status Report (1984). Threatened Protected Areas of
the World. (draft).
Dupuy, A. (1971). Les oiseaux et les mammifères de la cuvette du Djoudj
(delta du fleuve Sénégal).Bull. IFAN 33,
A (1): 237-248.
Dupuy, A. (1971). Contribution à l'étude de l'avifaune du delta du Sénégal.
Bull.IFAN 33, A(3):737-753
Dupuy, A.R. (1971). Mission au nouveau parc national des oiseaux du Djoudj.
Notes Africaines 132.
Dupuy, A.R. (1972). Le parc national des oiseaux du Djoudj. Bull.IFAN
34, A(3): 775-781.
Dupuy, A.R. and Suiro, P. (n.d.) Les Oiseaux du Djoudj. IUCN/WWF.
88 pp.
Larivière, J. and Dupuy, A.R. (1978). Sénégal: Ses Parcs, Ses Animaux.
Editions F.Nathan, Paris.
Pieterse, A. (2000). Aquatic weed management. In van Rijn, P. (ed.) Weed
Management in the Humid and Semi-humid Tropics. Royal Tropical Institute,
Amsterdam, The Netherlands. pp. 169-176.
Roux, F., Jarry, G., Maheao & Tamisier, R. (1976). Importance, structure
et origine des populations d'Anatides hivernant dans le delta du Sénégal.
L'Oiseau R.F.O. 46: 299-336 and 47: 1-24.
Secretariat d'Etat Charge de la Nature. (1974). Le Parc National
des Oiseaux du Djoudj, Dakar.
Thorsell, J. (1985). World Heritage Report - 1984. Parks 10(1):
8-9.
Triplet, P.,Tiega, A. & Pritchard, D. (2000). Mission Report.
Djoudj National Bird Sanctuary, Senegal, Sept. 2000, for UNESCO
World Heritage Bureau, Paris.
UNESCO World Heritage Committee (2001) Report on the 24th
Session of the World Heritage Committee.
UNESCO World Heritage Committee (2002) Report on the 25h
Session of the World Heritage Committee.
Van den Top, G.(1990). Senegal delta and lower valley. In Fiselier,
J. Living Off the Floods. Edwin, Leiden.
Voisin, C. (1983). Les ardeides du delta du fleuve Senegal. L'Oiseau
et Revue Francaise d'Ornithologie. 53(4).
DATE April 1985. Updated 5/1990,10/1995, March
2002 |