Lake Nokoué is a
lake
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...
in the southern part of
Benin
Benin, officially the Republic of Benin, is a country in West Africa. It was formerly known as Dahomey. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north-west, and Niger to the north-east. The majority of its po ...
. It is wide and long and covers an area of .
The lake is partly fed by the
Ouémé River and the
Sô River, both of which deposit sediments from throughout the region in the lake.
The city of
Cotonou
Cotonou (; ) is the largest 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 city lies ...
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 a large, diverse, and widespread family of percomorph fish in the family Cichlidae, order Cichliformes. At least 1,760 species have been scientifically described, making it one of the largest vertebrate families, with on ...
,
Clupeidae 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 grounds). Commercial fisheries include wild fisheries and fish far ...
became more stressed during the 1990s, as more people began fishing on the lake.
Fishing is typically
artisanal
An artisan (from , ) 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, sculpture, clothing, food ite ...
, with small crew
dugout canoe
A dugout canoe or simply dugout is a boat made from a hollowed-out tree. Other names for this type of boat are logboat and monoxylon. ''Monoxylon'' (''μονόξυλον'') (pl: ''monoxyla'') is Greek''mono-'' (single) + '' ξύλον xylon'' (tr ...
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), that is, square metres (), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. ...
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'') an ...
.
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 landforms 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, 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 natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...
.
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
Mud (, or Middle Dutch) is loam, silt or clay mixed with water. Mud is usually formed after rainfall or near water sources. Ancient mud deposits hardened over geological time to form sedimentary rock such as shale or mudstone (generally cal ...
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. Lutrinae is a branch of the Mustelidae family, which includes weasels, badgers, mink, and wolverines, among ...
.
References
External links
BirdLife Data Zone
Nokoue
Ramsar sites in Benin
Important Bird Areas of Benin
{{Benin-geo-stub