Lake Nokoué is a
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
in the southern part of
Benin
Benin ( , ; french: Bénin , ff, Benen), officially the Republic of Benin (french: République du Bénin), and formerly Dahomey, is a country in West Africa. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north ...
. It is wide and long and covers an area of .
The lake is partly fed by the
Ouémé River
The Ouémé River, also known as the Weme River, is a river in Benin. It rises in the Atakora Mountains, and is about long. It flows past the towns of Carnotville and Ouémé to a large delta on the Gulf of Guinea near the seaport city of Coto ...
and the
Sô River, both of which deposit sediments from throughout the region in the lake.
The city of
Cotonou
Cotonou (; fon, Kútɔ̀nú) is a city in Benin. Its official population count was 679,012 inhabitants in 2012; however, over two million people live in the larger urban area.
The urban area continues to expand, notably toward the west. The ci ...
sits on the southern border of the lake. Sections of the population of Cotonou have been displaced by coastal and lake flooding.
On the northern edge of the lake is the town of
Ganvié.
Economy
Because of its diverse wildlife, the lake provides an important source of food and economic activity for these towns.
Fishing is best when water is low between November and June.
Fishing is typically of 30 species of fish, with fish from the
Cichlid
Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this ...
,
Clupeidae
Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids include many of the most important food fishes in the world, and are also commonly caught for production of ...
and
Penaeidae
Penaeidae is a family of marine crustaceans in the suborder Dendrobranchiata, which are often referred to as penaeid shrimp or penaeid prawns. The Penaeidae contain many species of economic importance, such as the tiger prawn, whiteleg shrimp, ...
families making 85% of the catch.
The
fishery
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...
became more stressed during the 1990s, as more people began fishing on the lake.
Fishing is typically
artisanal
An artisan (from french: artisan, it, artigiano) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art, s ...
, with small crew
dugout canoe
A dugout canoe or simply dugout is a boat made from a hollowed tree. Other names for this type of boat are logboat and monoxylon. ''Monoxylon'' (''μονόξυλον'') (pl: ''monoxyla'') is Greek – ''mono-'' (single) + '' ξύλον xylon'' (t ...
s catching small batches of fish.
The estimated fish production of the lake is 2 tonnes per
hectare
The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is a ...
per year.
The lake is also used for
Acadja, a type of
fish breeding facility.
Hydrology
The lake, in large part, is a
lagoon
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') a ...
.
With the surrounding low-lying
topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps.
Topography is a field of geoscience and planetary sci ...
, the lake is expected to double in size and flood as the
current global climate change gradually affects the sea level.
This development carries a risk of future
salinisation
Soil salinity is the salt content in the soil; the process of increasing the salt content is known as salinization. Salts occur naturally within soils and water. Salination can be caused by natural processes such as mineral weathering or by the ...
, which will make the freshwater lake more
brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...
and potentially change its
ecology
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...
.
Different sections of the lake currently alternate between freshwater and brackish ecosystems at an average depth of .
Normal temperatures throughout the lake are between .
The lake is a site of deposition of both pesticides and heavy metals from upstream industry and human habitation.
Though the pesticides are only present in fish at less than toxic levels,
the heavy metals in the waters can reach levels in fish both unhealthy for humans and the fish.
Geology
The floor of the lake is a mixture of sand, muddy-sand and
mud
A MUD (; originally multi-user dungeon, with later variants multi-user dimension and multi-user domain) is a Multiplayer video game, multiplayer Time-keeping systems in games#Real-time, real-time virtual world, usually Text-based game, text-bas ...
layers.
Ecology
Lake Nokoué has at least 78 species of fish.
A number of bird species exploit the wide variety of fish as food, as well as species of
otter
Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes wea ...
.
References
External links
BirdLife Data Zone
Nokoue
Ramsar sites in Benin
Important Bird Areas of Benin
{{Benin-geo-stub