533
D. Kar, Wetlands and Lakes of the World,
DOI 10.1007/978-81-322-1023-8_24, © Springer India 2013
Africa is a land of abundant water resources and
rich biodiversity. Many of the mighty rivers and
enormous lentic bodies are situated in Africa. An
account of some of the wetlands of Africa is
given below.
24.1 Wetlands of Tanzania
Tanzania is a country in Africa with many lentic
bodies. An account is given below.
Lake Natron (Plate 24.1 ) is a salt lake located
between 02° 25′ S and 36° 00′ E in northern
Tanzania, close to the Kenyan border, in the
eastern branch of Africa’s Great Rift Valley. The
wetland (commonly called lake) is fed by the
Ewaso Ng’iro River and also by mineral-rich hot
springs. It is quite shallow and is typically a wetland because it is less than 3 m in depth. It varies
in width depending on its water level, which
changes due to high levels of evaporation, leaving high levels of salt and other minerals. The
surrounding country is dry and receives irregular
rainfall. Temperatures in the lake may rise up to
50 °C. Depending on rainfall, the pH may attain
a value of 9–10.5. The wetland water seems to
have a characteristic colour.
24.1.1 Flora
As water evaporates during the dry season, salinity levels increase to a point at which salt-loving
microorganisms begin to thrive. The salt-loving
microbes include some cyanobacteria, tiny
bacteria which grow in water and make their own
food by photosynthesis as plants do. The red pigment in the cyanobacteria produces the deep reds
of the open water of the wetland and orange
colours in the shallow parts of the wetland. The
number of cyanobacteria increase with increase
in salinity. The alkali salt crust on the surface of
the wetland is also often coloured red or pink by
the salt-loving microbes which live there. Lake
Natron is also a home to endemic algae.
24.1.2 Fauna
The high temperature (up to 41 °C) and the high
and very variable salt content of the wetland do
not seem to support much wildlife. However, it is
an important habitat for the fl amingos and is
home to invertebrates and fi sh that can survive in
salt water. Further, this wetland is the only regular
breeding ground in East Africa for the 2.5 million
endangered lesser fl amingos. Moreover, Lake
Natron is also considered to be a safe breeding
ground for lesser fl amingos, because its caustic
environment is a barrier against predators trying
to reach their nests. As stated earlier, it may be
noted here that the number of cyanobacteria
increase with increase in salinity and, thus, the
wetland may be able to support more nests. These
fl amingos, the largest fl ock in East Africa, gather
along saline lakes in the region, where they feed
on Spirulina ( a blue-green alga with red pigments ).
In addition, the greater fl amingos also breed on
24
Wetlands of Africa
D. Kar, Wetlands and Lakes of the World,
DOI 10.1007/978-81-322-1023-8_24, © Springer India 2013
Africa is a land of abundant water resources and
rich biodiversity. Many of the mighty rivers and
enormous lentic bodies are situated in Africa. An
account of some of the wetlands of Africa is
given below.
24.1 Wetlands of Tanzania
Tanzania is a country in Africa with many lentic
bodies. An account is given below.
Lake Natron (Plate 24.1 ) is a salt lake located
between 02° 25′ S and 36° 00′ E in northern
Tanzania, close to the Kenyan border, in the
eastern branch of Africa’s Great Rift Valley. The
wetland (commonly called lake) is fed by the
Ewaso Ng’iro River and also by mineral-rich hot
springs. It is quite shallow and is typically a wetland because it is less than 3 m in depth. It varies
in width depending on its water level, which
changes due to high levels of evaporation, leaving high levels of salt and other minerals. The
surrounding country is dry and receives irregular
rainfall. Temperatures in the lake may rise up to
50 °C. Depending on rainfall, the pH may attain
a value of 9–10.5. The wetland water seems to
have a characteristic colour.
24.1.1 Flora
As water evaporates during the dry season, salinity levels increase to a point at which salt-loving
microorganisms begin to thrive. The salt-loving
microbes include some cyanobacteria, tiny
bacteria which grow in water and make their own
food by photosynthesis as plants do. The red pigment in the cyanobacteria produces the deep reds
of the open water of the wetland and orange
colours in the shallow parts of the wetland. The
number of cyanobacteria increase with increase
in salinity. The alkali salt crust on the surface of
the wetland is also often coloured red or pink by
the salt-loving microbes which live there. Lake
Natron is also a home to endemic algae.
24.1.2 Fauna
The high temperature (up to 41 °C) and the high
and very variable salt content of the wetland do
not seem to support much wildlife. However, it is
an important habitat for the fl amingos and is
home to invertebrates and fi sh that can survive in
salt water. Further, this wetland is the only regular
breeding ground in East Africa for the 2.5 million
endangered lesser fl amingos. Moreover, Lake
Natron is also considered to be a safe breeding
ground for lesser fl amingos, because its caustic
environment is a barrier against predators trying
to reach their nests. As stated earlier, it may be
noted here that the number of cyanobacteria
increase with increase in salinity and, thus, the
wetland may be able to support more nests. These
fl amingos, the largest fl ock in East Africa, gather
along saline lakes in the region, where they feed
on Spirulina ( a blue-green alga with red pigments ).
In addition, the greater fl amingos also breed on
24
Wetlands of Africa