Lake Nokoué is an extensive lagoon of c.16,000 ha extent, 20 km wide by 11 km long (north to south), immediately north of Cotonou. Its northern shore is formed by the deltas of the So and Ouémé rivers. It is connected to the sea not only via a channel through Cotonou, but also by another to the Lagune de Porto-Novo to the east and thence to the coast in Nigeria. On the western edge is the remarkable aquatic town of Ganvié, built on stilts made of bamboo or tree-trunks sunk into the water. The southern edge of the lake has the highest salinity, and is fringed with Typha australis as well as the ubiquitous grass Paspalum vaginatum. The proposed IBA includes not only the lake itself but also the seasonally inundated forest (Berlinia grandiflora and Dalium guineense), swamp-forest (Mitragyna inermis and Raphia hookeri), marshes and flood-plains of rivers north of it, up the Ouémé river as far as the village of Sagon, 10 km south-east of Zangnanado.
See Box and Table 2 for key species. Large populations of waterbirds use the lake and surrounding areas. These include, in addition to those listed below, Egretta ardesiaca, E. garzetta, Tringa glareola, T. stagnatilis, T. nebularia, T. erythropus and Chlidonias hybridus. There is also a record of Gallinago media. It is expected that more species of the Guinea–Congo Forests biome will be found to occur. In addition, five species of the Sudan–Guinea Savanna biome (A04) have been recorded; see Table 2.
Non-bird biodiversity: Small numbers of Tragelaphus spekii (LR/nt) are thought to persist but hunting pressure is intense. There are also records of Cercopithecus erythrogaster (VU) and Trichechus senegalensis (VU).
Pressure/threats to key biodiversity
Much of the area was declared a Ramsar Site, known as Basse Vallée de l’Ouémé, Lagune de Porto-Novo, Lac Nokoué and covering 91,600 ha, in January 2000. Threats include hunting, poaching, pollution, mangrove destruction and deforestation. Traditional fishing methods may, however, benefit birds. Fishermen plant branches in the muddy lagoon bottom, surrounded by platforms of bamboo sticks and palm-leaves. When the leaves on the branches start to decompose, fish congregate to feed at these sites, known as acadja, before boatmen (and birds) return to catch them.
BirdLife International (2020) Important Bird Areas factsheet: Lake Nokoué. Downloaded from
http://www.birdlife.org on 29/09/2020.