This site lies some 12 km south of St Louis and about 60 km south-west of Djoudj wetlands (site SN001). The reserve consists of an extensive lagoon of variable salinity in a shallow depression, with a relict mangrove along the shores. The lagoon is replenished both by seasonal rainfall and by inflow of salt water from the Senegal river mouth and water-levels can be controlled artificially by means of a sluice gate. In addition to the official reserve, a number of brackish lagoons around the town of St Louis, all linked to the river estuary, are included in the IBA. These vary significantly in size, depending on the water-level in the Senegal river and the rainfall. The vegetation around the lagoons is Sahelian thorn-bush savanna dominated by Acacia spp. The lagoons are highly productive and those outside the reserve support important local fishing economies. The surrounding areas are used for livestock-grazing, agriculture and fuelwood-collection, all of which (together with fishing) are prohibited in the reserve itself.
See Box for key species. The site harbours a wide variety of Palearctic migrant ducks and waders, and important numbers of gull and tern species. Larus audouinii is recorded regularly in small numbers along the river and lagoons (maximum 17 birds recorded from St Louis lagoons and Parc National de la Langue de Barbarie [site SN006], combined, in 1994). In addition to the species listed in the Box, large numbers of Anas clypeata, Limosa limosa, Calidris minuta and C. ferruginea have been recorded and Egretta gularis occurs regularly along the lagoon edges. Pelecanus onocrotalus occurs in winter numbers close to the IBA thresholds (e.g. 650 at Guembeul, 525 at St Louis lagoons in the late 1980s and 1990s), and Sterna sandvicensis and S. albifrons are recorded wintering in numbers which exceed IBA thresholds, but these records cover the whole coastline from St Louis to Kayar (i.e. also including Parc National de la Langue de Barbarie [site SN006]). There is a record from 1988 of 4,000 Larus genei, but subsequent numbers have never exceeded the hundreds (still regularly over the IBA threshold for the species). Sterna nilotica and S. albifrons are recorded breeding at Guembeul. There is considerable interchange of birds between this site and site SN006, which lies to the south, further out to sea along the extensive Senegal river mouth. In addition, five species of the Sahel biome have been recorded (see Table 2).
Non-bird biodiversity: A project to reintroduce mammals and reptiles which were previously common in the Sahel region is based at Guembeul Avifaunal Reserve, where there is a captive-breeding enclosure for Gazella dama (EN), Oryx dammah (EW) and the tortoise Geochelone sulcata (VU). The plan is for reintroductions to be made in the northern Ferlo region (see Ferlo North, site SN007).
Pressure/threats to key biodiversity
The site incorporates Guembeul Avifaunal Reserve (720 ha), which is also a Ramsar Site. Conservation measures have resulted in regeneration of degraded vegetation around the lagoon of Guembeul, but there is no official management plan for the reserve and no control of activities such as fuelwood-collection and fishing within the rest of the IBA. Ongoing problems include illegal fishing and salt extraction (within the reserve) and cutting of Acacia trees. Nature conservation activities carried out within the reserve include the experimental breeding centre for Sahelian mammals and reptiles, conservation education and some tourism. The town of St Louis is a major tourism centre and there is no control of visitors or recreational use of the lagoons around the town. Recent problems in the reserve have been caused by the breach of the sluice gate in 1996, which meant that water-levels could not be maintained and the lagoon began drying out two months earlier than normal, reducing its value for waders and flamingos. There is an urgent need to replace and renew the water-control mechanisms to allow for effective control of water-levels. Lack of funding for repair and maintenance jeopardize proper management of the reserve and the breeding centre.
BirdLife International (2021) Important Bird Areas factsheet: Guembeul Avifaunal Reserve and St Louis lagoons. Downloaded from
http://www.birdlife.org on 27/10/2021.