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th
13 World Lake Conference
International Lake Environment Committee Foundation
Websites:
http//www.ilec.org
http//www.chinalakes.org
November 1 – 5, 2009
Wahun, China
Session Paper Topic
OUR LAKES, OUR FUTURE.
By
CHEGE DAVID MATHEA
REG. NO.: WLC08111423317
P. O. Box 312-00902
Kikuyu, Kenya
Tel: +254202397454
Cell +254722699673
E-mail: [email protected]
Submitted on 25th March 2009 via e-mail.
13TH WORLD LAKE CONFERENCE,
OUR LAKES, OUR FUTURE
CONTENTS
November 1, 2009
PAGE
OUR LAKES, OUR FUTURE
ABSTRACT.................................................................................. 3
LAKE VICTORIA.......................................................................... 7
LAKE NAKURU ........................................................................... 8
LAKE TURKANA ......................................................................... 10
LAKE MAGADI ............................................................................ 11
LAKE NAIVASHA ........................................................................ 12
LAKE BARINGO.......................................................................... 13
LAKE BOGORIA.......................................................................... 15
LAKE ELMENTEITA.................................................................... 16
LAKE KAMNAROK ..................................................................... 17
LAKE LOGIPI............................................................................... 17
IMPACT OF HUMAN ACTIVITY ON OUR LAKES..................... 19
CONCLUSION
THE WAY FORWARD TOWARDS THE FUTURE ..................... 23
REFERENCE ............................................................................... 25
Chege David Mathea Reg No: WLC0811142317
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OUR LAKES, OUR FUTURE.
ABSTRACT
The Africa continent is endowed with many lakes. There are two categories of lakes;
those that form inland drainage, most of which are salty e.g. Okavango in Botswana
and Shots in the Atlas mountains, and those drained by rivers which are mainly fresh
water e.g. L. Victoria drained by R. Nile and L. Ngami by R. Zaire.
African lakes are categorised according to their formation.
Rift Valley lakes were
formed when the floor of the valley was filled with water. Most of these lakes are long,
narrow and deep with steep cliff-like edges. They are mostly salty due to their inland
drainage. They do not have an outlet to the sea except L. Tanganyika drained by R.
Lukuya during the wet season, L. Malawi by R. Shire and L. Naivasha which has an
Underground outlet.
Warping lakes were formed by the down warping of the ancient plateau.
The
depression so formed was later filled with water to form lakes. Examples include L.
Victoria in East Africa, L. Kyoga in Uganda and L. Chad in Chad.
Volcanic crater lakes were formed through volcanic activities. When the volcanoes
erupted, the lava cooled inside a vent and a depression formed due to the subsidence
of lava. This later filled with water to form a crater lake e.g. Ngorongoro crater in
Tanzania.
Deposition lakes are mainly ox-bow lakes formed at the old stage of the river before the
mouth. Once a pronounced meander is separated from the main steam by deposition
and erosion, an ox-bow lake is formed. Examples include L. Narugi on R. Tana in
Kenya and L. Kilombero in Tanzania.
Glacial lakes were formed in depressions or basins resulting from glacial erosion as
huge blocks of ice glide down the mountain side. They are known as corries or tarns
e.g. the Teleki Tarn on Mt. Kenya.
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Wind eroded lakes are found in huge depressions created by wind erosion in the desert
sands.
Once the water table is reached the depressions fill with water.
Due to
excessive evaporation, the lakes turn into muddy swamps with small water points
known as oases. An example of such desert depressions is the Quattara in Egypt.
Sometimes these oases may dry up completely forming salt flats known as playas.
Man-made lakes are formed as a result of damming of rivers where multi-purpose river
projects have been established. They are important for production of Hydro-electric
power (H.E.P), transport, fishing, irrigation and regulating flooding. Examples include L.
Nasser behind the Aswan High Dam in Egypt, L. Volta behind the Akosombo Dam in
Ghana and L. Kariba behind the Kariba Dam on R. Zambezi.
Kenyan lakes either differ from each other or are similar due to the aspects of formation,
location and human interference.
Lake Victoria is one of the Great Lakes of Africa. It is 68,800 square kilometres in size,
making it the continent's largest lake, the largest tropical lake in the world, and the
second widest fresh water lake in the world in terms of surface area.
Lake Nakuru is one of the Rift Valley soda lakes. It is a small shallow alkaline lake on
the southern edge of the town of Nakuru. The lake's level dropped dramatically in the
early 1990s but has since largely recovered.
Lake Turkana, formerly known as Lake Rudolf, is the most northern lake in the Kenya
Great Rift Valley. Its far end crosses into Ethiopia. It is the world's largest permanent
desert lake and the world's largest alkaline lake.
Lake Magadi is the southernmost lake in the Kenya Rift Valley. During the dry season,
it is 80% covered by soda and is well known for its wading birds, including flamingos.
Lake Magadi is a saline-alkaline lake, approximately 100 square kilometres in size,
which lies in a graben.
Lake Naivasha is a freshwater lake in Kenya, lying North-West of Nairobi, outside the
town of Naivasha. It is part of the Great Rift Valley.
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The name derives from the local Maasai name Nai'posha, meaning "rough water"
because of the sudden storms which can arise.
Lake Baringo is the second-most northern of the Great Rift Valley lakes of Kenya with a
surface area of about 130 km² and an elevation of about 970 m. The lake is fed by
several rivers, El Molo, Perkerra and Ol Arabel, and has no obvious outlet; the waters
are assumed to seep through lake sediments into the faulted volcanic bedrock.
Lake Bogoria is a saline-alkaline lake that lies in a volcanic region in a basin south of
Lake Baringo, a little north of the equator. Lake Bogoria is home, at times, to one of the
world's largest populations of lesser flamingos. Lake Bogoria is shallow, about 10 m
deep and is about 34 km long by 3.5 km wide, with a drainage basin of 700 km².
Lake Elmenteita is derived from the Maasai word muteita, meaning "dust place", a
reference to the dry and dusty quality of the area, especially between January and
March. The town of Gilgil is located near the lake. In the south-to-north sequence of Rift
Valley lakes, Elmenteita is located between Lake Naivasha and Lake Nakuru.
Human activities have had a very big impact on our lakes.
The three countries
bordering Lake Victoria—Uganda, Kenya and Tanzania —have been reluctant to the
idea of a tax on Nile perch exports proceeds to be applied to various measures to
benefit local communities and sustain the fishery.
In 2002, Uganda completed a second hydroelectric complex in the area. By 2006 the
water levels in Lake Victoria had reached an 80-year low, and Daniel Kull, an
independent hydrologist living in Nairobi, raised an alarm that within a year, approx. 4%
of the lake would be drained!
The water lily (hyacinth), a native of the tropical Americas, was introduced by Belgian
colonists to Rwanda to beautify their holdings but the result has been difficulties in
transportation, fishing, hydroelectric power generation and drinking water supply.
The situation in Lake Nakuru is nothing better. Approximately 50,000 inhabitants of
Nakuru town pour some 1.1 million gallons of partially treated sewage into the shallow,
18-square-mile lake every day.
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Similarly, to the east, south and west of Lake Naivasha is agricultural land where DDT,
Dieldrin and a host of other pesticides are widely used and eventually reach lake.
According to scientists; they may soon reach levels that could wipe out much of the
aquatic life.
The way forward towards the future is that Kenyans have resolved to embark on
measures to ensure conservation of our lakes for sustainable utilization in the future
such as protection of the habitat globally, increased awareness and understanding of
environmental conservation, Development of replicable models, improved collaboration,
empowered local communities, protection of endangered habitats and improved
capacity among all stakeholders.
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LAKE VICTORIA
Lake Victoria or Victoria Nyanza (also known as Ukerewe and Nalubaale) is one of the
Great Lakes of Africa. It is 68,800 square kilometres in size, making it the continent's
largest lake, the largest tropical lake in the world, and the second widest fresh water
lake in the world in terms of surface area. Being relatively shallow for its size (with a
maximum depth of 84 m and a mean depth of 40 m) Lake Victoria ranks as the seventh
largest freshwater lake by volume, containing 2,750 cubic kilometres of water. It is the
source of the longest branch of the River Nile, the White Nile, and has a water
catchment area of 184,000 square kilometres. It is a biological hotspot with great
biodiversity. The lake lies within an elevated plateau in the western part of Africa's
Great Rift Valley and is subject to territorial administration by Tanzania, Uganda and
Kenya. The lake has a shoreline of 3,440 km and has more than 3,000 islands, many of
which are inhabited. These include the Ssese Islands in Uganda, a large group of
islands in the northwest of the lake that are becoming a popular destination for tourists.
Lake Victoria is relatively young; its current basin formed only 400,000 years ago, when
westward-flowing rivers were dammed by an up thrown crystal block. The lake's
shallowness, limited river inflow, and large surface area relative to its volume make it
vulnerable to climate changes. Cores taken from its bottom show that Lake Victoria has
dried up completely three times since it formed. These drying cycles are probably
related to past ice ages, which are times when precipitation declined globally. The lake
last dried out 17,300 years ago, and filled again beginning 14,700 years ago; the
fantastic adaptive radiation of its native cichlids has taken place in the short period of
time since then.
The ecosystems of Lake Victoria and its surroundings have been badly affected by
human influence. In 1954, the Nile perch was first introduced into the lake's ecosystem
in an attempt to improve fishery yields of the lake. Introduction efforts intensified during
the very early-1960s. The species was present in small numbers until the early to mid1980s, when it underwent a massive population expansion and came to dominate the
fish community and ecology of the world's largest tropical lake.
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Also introduced was the Nile tilapia, now an important food fish for local consumption.
The Nile perch proved ecologically and socio-economically devastating. Together with
pollution born of deforestation and overpopulation (of both people and domestic
animals), the Nile perch has brought about a massive transformation in the lake's
ecosystem and to the disappearance of hundreds of endemic haplochromine cichlid
species. Many of these are now presumed to be entirely extinct.
Also vanished from Lake Victoria is one of two native species of tilapia, the Singidia
tilapia or ngege. The ngege is superior in taste and texture to Nile tilapia, but it does not
grow as fast or as large and produces fewer young. Ngege and some representatives
of haplochromine diversity survive in minute swamp ponds and lakes that dot the Lake
Victoria Basin. The initial good returns on Nile perch catches, at their peak delivering
export revenues of several hundred million dollars a year, have diminished dramatically
due to poor enforcement of fisheries regulations. The proceeds from Nile perch sales
remain an important economic engine in the region, but the resulting wealth is very
poorly distributed and the overall balance sheet on the Nile perch introduction to Lake
Victoria is well into the red despite the enormous value of the perch landings as an
export commodity.
LAKE NAKURU
Lake Nakuru is one of the Rift Valley soda lakes. It is a small shallow alkaline lake on
the southern edge of the town of Nakuru. The lake's level dropped dramatically in the
early 1990s but has since largely recovered. It varies from 5 to 45 square kilometres
and lies about 160 kilometres north of Nairobi. Nakuru means "Dust or Dusty Place" in
Maasai language. Lake Nakuru lies within the Lake Nakuru National Park (188 km²)
that was established in 1961. It started off small, only encompassing the famous lake
and the surrounding mountainous vicinity. Now it has been extended to include a large
part of the savannahs. The lake's abundance of algae attracts the vast quantity of
flamingos that famously lines the shore. Other birds also flourish in the area, as do
warthogs, baboons and other large mammals. Black and White rhinos have also been
introduced.
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Lake Nakuru National Park is best known for its thousands, sometimes millions of
flamingos nesting along the shores. The surface of the shallow lake is often hardly
recognizable due to the continually shifting mass of pink. The number of flamingos on
the lake varies with water and food conditions and the best vantage point is from
Baboon Cliff. Also of interest is an area of 188 km around the lake fenced off as a
sanctuary to protect Rothschild giraffes and black rhinos.
The park has recently been enlarged partly to provide the sanctuary for the black rhino.
This undertaking has necessitated a fence - to keep out poachers rather than to restrict
the movement of wildlife. The park marches for 12.1 km on the south eastern boundary
with the Soysambu conservancy which represents a possible future expansion of the
habitat up to Lake Naivasha for the rhinos and the only remaining wildlife. The park now
has more than 25 rhinoceros, one of the largest concentrations in the country, so the
chances of spotting these survivors are good. There are also a number of Rothschild's
giraffe, again trans-located for safety from western Kenya beginning in 1977.
Waterbucks are very common and both the Kenyan species are found here. Among the
predators are lions and leopards, the latter being seen much more frequently in recent
times. The park also has large sized pythons that inhabit the dense woodlands, and can
often be seen crossing the roads or dangling from trees.
The lake is world famous as the location of the greatest bird spectacle on earth, with
myriads of fuchsia pink flamingos whose numbers are vast, often more than a million or even two million. They feed on the abundant algae, which thrives in the warm waters.
Scientists reckon that the flamingo population at Nakuru consumes about 250,000 kilos
of algae per hectare of surface area per year. There are two types of flamingo species:
the Lesser flamingo can be distinguished by its deep red carmine bill and pink plumage
unlike the Greater, which has a bill with a black tip. The Lesser flamingos are ones that
are commonly pictured in documentaries mainly because they are large in number.
The number of flamingos has been decreasing recently, perhaps due to too much
human presence, pollution resulting from industrial waterworks nearby who dump waste
into the waters, or simply because of changes in water quality which makes the lake
temporarily inhospitable. Usually, the lake recedes during the dry season and floods
during the wet season.
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In recent years, there have been wide variations between the dry and wet seasons'
water levels. It's suspected that this is caused by increasing watershed land conversion
to intensive crop production and urbanization, both which reduce the capacity of soils to
absorb water, recharge ground waters and thus increase seasonal flooding.
Pollution and drought destroy the flamingos' food (Cyano-bacteria) or blue-green algae,
causing them to migrate to the nearby Lakes, such as lakes Elmenteita, Simbi Nyaima
and Bogoria. Local climate changes have also been hypothesized to contribute to the
changing environmental conditions in the lake’s catchment. Recent media reports
indicate increasing concern among stakeholders, as mass flamingo migrations and
deaths could spell doom to the tourism industry. The flamingos feed on algae, created
from their droppings mixing in the warm alkaline waters, and plankton. But flamingos
are not the only avian attraction, also present are two large fish eating birds, pelicans
and cormorants. Despite the tepid and alkaline waters, a diminutive fish, Tilapia
grahami has flourished after being introduced in the early 1960s. The lake is rich in
other birdlife. There are over 400 resident species on the lake and in the surrounding
park. Thousands of both little grebes and white winged black terns are frequently seen
as are stilts, avocets, ducks, and in the European winter the migrant waders. Also, a
bunch of Zebra graze nearby.
LAKE TURKANA
Lake Turkana, formerly known as Lake Rudolf, is the most northern lake in the Kenya
Great Rift Valley. Its far end crosses into Ethiopia. It is the world's largest permanent
desert lake and the world's largest alkaline lake. By volume it is the world's fourth
largest salt lake after the Caspian Sea, Lake Issyk-Kul and the (shrinking) Aral Sea.
Among all lakes it ranks twentieth in size. The water is potable but not palatable. It
supports a rich lacustrine wildlife. The climate is hot and very dry. The rocks of the
surrounding area are predominantly volcanic. Central Island is an active volcano,
emitting vapours. Outcrops and rocky shores are found on the East and South shores
of the lake, while dunes, spits and flats are on the West and North, at a lower elevation.
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On-shore and off-shore winds can be extremely strong as the lake warms and cools
more slowly than the land. Sudden, violent storms are frequent. Three rivers (the Omo,
Turkwel and Kerio) flow into the lake, but lacking outflow its only water loss is by
evaporation. Lake volume and dimensions are variable. For example, its level fell by 10
meters between 1975 and 1993.
Due to temperature, aridity and geographic inaccessibility, the lake retains its wild
character. Nile crocodiles are found in great abundance on the flats. The rocky shores
are home to scorpions and carpet vipers. Although the lake and its environs have been
popular for expeditions of every sort under the tutelage of guides, rangers and
experienced persons, they certainly must be considered hazardous for unguided
tourists.
Lake Turkana National Parks are now listed as a UNESCO World Heritage Site. Sibiloi
National Park lies on the lake's eastern shore, while Central Island National Park and
South Island National Park lie in the lake. Both are known for their crocodiles.
LAKE MAGADI
Lake Magadi is the southernmost lake in the Kenya Rift Valley, lying in a catchment of
faulted volcanic rocks, north east of Lake Natron. During the dry season, it is 80%
covered by soda and is well known for its wading birds, including flamingos.
Lake Magadi is a saline-alkaline lake, approximately 100 square kilometres in size,
which lies in a graben. The lake is an example of a "saline pan". The lake water, which
is dense sodium carbonate brine, precipitates vast quantities of the mineral trona
(sodium sesqui-carbonate). In places, the salt is up to 40 m thick. The lake is recharged
mainly by saline hot springs with temperatures up to 86°C that discharge into alkaline
"lagoons" around the lake margins, there being little surface runoff in this arid region.
Most hot springs lie along the north-western and southern shorelines of the lake. During
the rainy season a thin layer of brine covers much of the saline pan, but this evaporates
rapidly leaving a vast expanse of white salt that cracks to produce large polygons.
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A single species of fish, a cichlid Alcolapia grahami, inhabits the hot, highly alkaline
waters of this lake basin and is commonly seen in some of the hot spring pools around
the shoreline where the water temperature is less than 45°C.
Lake Magadi was not always so saline. Several thousand years ago (during the late
Pleistocene to mid-Holocene) the Magadi basin held a freshwater lake with many fish,
whose remains are preserved in the High Magadi Beds, a series of lacustrine and
volcaniclastic sediments preserved in various locations around the present shoreline.
Evidence also exists for several older Pleistocene precursor lakes that were much
larger than present Lake Magadi. At times, Lake Magadi and Lake Natron were united
as a single larger lake.
Lake Magadi is also well known for its extensive deposits of siliceous chert. There are
many varieties including bedded cherts that formed in the lake and intrusive dyke-like
bodies that penetrated through overlying sediments while the silica was soft. Most
famous is "Magadi-type chert", which formed from a sodium silicate mineral precursor
magadiite that was discovered at Lake Magadi during the 1960s.
Magadi township lies on the lake's east shore, and is home to the Magadi Soda factory,
owned by Tata India since December 2005. This factory produces soda ash, which has
a range of industrial uses.
LAKE NAIVASHA
Lake Naivasha is a freshwater lake in Kenya, lying North-West of Nairobi, outside the
town of Naivasha. It is part of the Great Rift Valley. The name derives from the local
Maasai name Nai'posha, meaning "rough water" because of the sudden storms which
can arise. The lake has a surface area of 139 km², and is surrounded by a swamp
which covers an area of 64 square km, but this can vary largely depending on rainfall. It
is situated at an altitude of 1,884 metres (6,180 ft). The lake has an average depth of 6
m (20 ft), with the deepest area being at Crescent Island, at a maximum depth of 30 m
(100 ft). Njorowa Gorge used to form the lake's outlet, but it is now high above the lake
and forms the entrance to Hell's Gate National Park.
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The lake is home to a variety of wildlife; over 400 different species of bird have been
reported. There is a sizeable population of hippos in the lake. There are two smaller
lakes in the vicinity of Lake Naivasha: Lake Oloiden and Lake Sonachi (a green crater
lake). The Crater Lake Game Sanctuary lies nearby, while the lake shore is known for
its population of European immigrants and settlers. Between 1937 and 1950 the lake
was used as a landing place for flying boats on the Imperial Airways passenger and
mail route from Southampton in Britain to South Africa. It linked Kisumu and Nairobi.
Floriculture forms the main industry around the lake. However, the largely unregulated
use of lake water for irrigation is reducing the level of the lake and is the subject of
concern in Kenya. Fishing in the lake is also another source of employment and income
for the local population. The lake varies in level greatly and almost dried up entirely in
the 1890s. Having refilled, water levels are now dropping again. The town of Naivasha
(formerly East Nakuru) lies on the north east edge of the lake.
In 1981, the first geothermal plant for Lake Naivasha was commissioned and by 1985,
a total of 45 MW of electricity was being generated in the area. The water level for Lake
Naivasha reached a low level of 0.6 m depth in 1945, but the water level rose again,
with minor drops, to reach a maximum depth nearly 6 m in 1968. There was another
major decline of the water level in 1987, when the depth reached 225 cm above the
lake bottom.
The decline of the lake water level in 1987 increased concern in the future of
geothermal industry, and it was speculated that Lake Naivasha underground water
might be feeding the geothermal reservoir at Olkaria. Hence, the decline in the lake
water would affect the future of the geothermal industry.
LAKE BARINGO
Lake Baringo is the second-most northern of the Great Rift Valley lakes of Kenya, after
Lake Turkana, with a surface area of about 130 km² and an elevation of about 970 m.
The lake is fed by several rivers, El Molo, Perkerra and Ol Arabel, and has no obvious
outlet; the waters are assumed to seep through lake sediments into the faulted volcanic
bedrock.
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It is one of the two freshwater lakes in the Rift Valley in Kenya, the other being Lake
Naivasha. It lies off the beaten track in a hot and dusty setting and over 470 species of
birds have been recorded there, occasionally including migrating flamingos.
The lake is part of the Great Rift Valley system. The Tugen Hills, an uplifted fault block
of volcanic and metamorphic rocks, lies west of the lake. The Laikipia Escarpment lies
to the east. Water flows into the lake from the Mau Hills and Tugen Hills. It is a critical
habitat and refuge for more than 500 species of birds and fauna, some of the migratory
water-bird species being significant regionally and globally. The lake also provides an
invaluable habitat for seven fresh water fish species. Lake fishing is important to local
social and economic development. Additionally the area is a habitat for many species of
animals including the hippopotamus, crocodile and many other mammals, amphibians,
reptiles and the invertebrate communities.
Fish stocks in the lake are now low and water levels have been reduced by droughts
and over-irrigation. The lake is commonly turbid with sediment, partly due to intense soil
erosion in the catchments, especially on the Loboi Plain south of the lake.
The lake has several small islands, the largest being Ol Kokwe Island. Ol Kokwe, an
extinct volcanic centre related to Korosi volcano north of the lake, has several hot
springs and fumaroles, some of which have precipitated sulphur deposits. A group of
hot springs discharge along the shoreline at Soro near the north-eastern corner of the
island.
Several important archaeological and palaeontological sites, some of which have
yielded fossil hominoids and hominins, are present in the Miocene to Pleistocene
sedimentary sequences of the Tugen Hills.
The main town near the lake is Marigat, while smaller settlements include Kampi ya
Samaki and Loruk. The area is increasingly visited by tourists and is situated at the
southern end of a region of Kenya inhabited largely by pastoralist ethnic groups
including Ilchamus, Rendille, Turkana and Kalenjin.
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LAKE BOGORIA
Lake Bogoria is a saline-alkaline lake that lies in a volcanic region in a basin south of
Lake Baringo, a little north of the equator. Lake Bogoria, like Lake Nakuru, Lake
Elmenteita, and Lake Magadi further south in the Rift Valley, and Lake Logipi to the
north, is home at times to one of the world's largest populations of lesser flamingos.
The lake is a Ramsar site and has been a protected National Reserve since November
29, 1973. Lake Bogoria is shallow, about 10 m deep and is about 34 km long by 3.5 km
wide, with a drainage basin of 700 km².
Local features include the Kesubo Swamp to the north and the Siracho Escarpment to
the east, both within the National Reserve. The reserve is also famous for its geysers
and hot springs.
The lake waters are of Na-HCO3-CO3 composition. They originate from inflow from the
Sandai and Emsos rivers, and from about 200 alkaline hot springs that are present at
three onshore sites: Loburu, Chemurkeu, and a southern group (Ng'wasis, Koibobei
and Losaramat). Other springs discharge directly from the lake floor. Lake Bogoria also
contains the highest concentration of true geysers in Africa (at least 18 are known). The
lake waters are saline-alkaline. The lake has no surface outlet so the water becomes
saline mainly through evaporation, which is high in this semi-arid region. The lake itself
is stratified with less dense surface waters lying on a denser more saline bottom waters.
Although hyper-saline, the lake is highly productive with abundant cyano-bacteria that
feed the flamingos. However, few other organisms inhabit the lake.
The lake has not always been saline. Sediment cores from the lake floor have shown
that freshwater conditions existed for several periods during the past 10,000 years, and
that lake level was up to about 9 m higher than its present level of about 990 m above
sea-level. At times it might have overflowed northward towards Lake Baringo. At times,
during the late Pleistocene it might have been united with a larger precursor of modern
Lake Baringo, but this is still uncertain.
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The lake area was the traditional home of the Endorois people, who were forced to
leave the area in the 1970s and are now challenging their removal at the African
Commission on Human and Peoples' Rights.
LAKE ELMENTEITA
Lake Elmenteita is derived from the Maasai word muteita, meaning "dust place", a
reference to the dry and dusty quality of the area, especially between January and
March. The town of Gilgil is located near the lake. In the south-to-north sequence of Rift
Valley lakes, Elmenteita is located between Lake Naivasha and Lake Nakuru. The
major Nairobi—Nakuru highway runs along the nearby escarpment affording motorists
a spectacular vista towards the lake. At the southern end of the lake lie the "Kekopey"
hot springs, in which the Tilapia Grahami breeds. Very popular for bathing, the local
Maasai claim that it can cure AIDS. The reed beds nearby are fishing grounds for Night
Herons and Pelicans
The Lake Elmenteita area saw its first white settlement when Lord Delamere (18791931) established his Soysambu, a 48,000-acre (190 km2) ranch, on the western side
of the lake. Delamere gave the land nearest the lake to his brother-in-law, the
Honourable Galbraith Lowry Egerton Cole (1881-1929), part of whose "Kekopey
Ranch", where he is buried, is preserved today as the Lake Elmenteita Lodge.
The nearby Soysambu estate is still occupied by Lord Delamere's descendants,
including the controversial Thomas P. G. Cholmondeley who has been instrumental in
setting up the Soysambu conservancy. The conservancy covers 2/3 of the shoreline
and is home to over 12,000 wild animals. The lake's shores are grazed by zebra,
gazelle, eland and families of warthog. Lake Elmenteita has been a Ramsar site since
2005. Nearby is the Kariandusi Museum, an important prehistoric site where stone
hand-axes and cleavers were discovered in 1928 by Dr. Louis Leakey.
At the Lake Nakuru/Elmenteita basin, over 400 bird species have been recorded.
Elmenteita attracts visiting flamingos, both the Greater and Lesser varieties, which feed
on the lake's crustacean and insect larvae and on its suspended blue-green algae,
respectively.
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Tilapia fish were introduced to the lake from Lake Magadi in 1962 and since that time
the flamingo population has dwindled considerably. The tilapia attract many fish-eating
birds that also feed upon the flamingo eggs and chicks. Over a million flamingos that
formerly bred at Elmenteita are now said to have sought refuge at Lake Natron in
Tanzania.
The lake is normally very shallow (less than 1 m deep) and bordered by tronaencrusted mudflats during the dry seasons. During the late Pleistocene and early
Holocene, Lake Elmenteita was at times expanded and united with Lake Nakuru,
forming a much larger dilute lake. Remnants of the former joined lake are preserved as
sediments at various locations around the lake basins, including former shorelines.
LAKE KAMNAROK
Lake Kamnarok is situated at the base of the Kerio Valley. The name originated from
the word narok, which is a species of water plant that was widely found in the lake in
the early stages of the lake formation. The lake is 1 km² in size. It was formed in year
1961 as a result of the Kerio River changing its course, therefore forming an oxbow
lake. The dramatic event of its formation saw people living in the area being evacuated
in order to save lives.
The lake was gazetted in 1984, and it saw the creation of the Lake Kamnarok Game
Reserve, which is the home of 500 elephants. Like other Great Rift Valley lakes, its
existence is being threatened, mainly because of farming activities in the area. There
are deep gullies that are likely lead to spilling of the water, thus joining it with the Kerio
River. A few measures have been taken to save the lake, including building of gabions.
The tributaries that empty their water to Lake Kamnarok include the rivers Ketipborok,
Cheplogoi, Oiwo, Lelabei and Torok.
LAKE LOGIPI
Lake Logipi is a saline-alkaline lake that lies at the northern end of the arid Suguta
Valley in the northern Rift. It is separated from Lake Turkana by the Barrier volcanic
complex, a group of young volcanoes that last erupted during the late 19th Century or
early 20th Century.
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Saline hot springs discharge on the northern shoreline of Lake Logipi and at Cathedral
Rocks near its southern limit, and help to maintain water at times of extreme aridity.
During the rainy season, the lake is also recharged from the Suguta River which flows
northward along the Suguta Valley, periodically forming a temporary lake, Lake Alablab,
which unites with Logipi.
Lake Logipi has a maximum depth of 3 to 5 m, and is about 6 km wide by 3 km long. Its
waters are of sodium bicarbonate composition. Efflorescent salt-crusts (trona) are
present around its margins. Flamingos frequently inhabit the saline waters feeding on
cyano-bacteria and other plankton.
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IMPACT OF HUMAN ACTIVITY ON OUR LAKES
The three countries bordering Lake Victoria—Uganda, Kenya and Tanzania —have
agreed in principle to the idea of a tax on Nile perch exports, proceeds to be applied to
various measures to benefit local communities and sustain the fishery. However, this
tax has not been put into force, enforcement of fisheries and environmental laws
generally are lax, and the Nile perch fishery remains in essence a mining operation.
Currently, the Nile perch is being over-fished. Populations of a few endemic cichlid
species have increased again, particularly one to three species of zooplankton-eating,
herring-like cichlids that school with the abundant native Silver Cyprinid, known locally
as dagaa (Tanzania), omena (Kenya) or mukene (Uganda). In 1996 The World Bank
funded a project to restore and sustain the ecology of Lake Victoria and its fisheries,
called LVEMP (Lake Victoria Environmental Management Project).
Meanwhile, the European Union invested another large sum in fisheries infrastructure
and monitoring. One product of these foreign aid programmes has been the training of
a new generation of East African aquatic ecologists, conservation professionals, and
fisheries scientists. There has also been an increase in the fishery research institutes of
the lake. The only outflow for Lake Victoria is at Jinja, Uganda, where it forms the
Victoria Nile. The water originally drained over a natural rock weir. In 1952, British
colonial engineers blasted out the weir and reservoir. A standard for mimicking the old
rate of outflow called the "agreed curve" was established, setting the maximum flow
rate at 300 to 1,700 cubic meters per second depending on the lake's water level.
In 2002, Uganda completed a second hydroelectric complex in the area, with World
Bank assistance. By 2006 the water levels in Lake Victoria had reached an 80-year low,
and Daniel Kull, an independent hydrologist living in Nairobi, Kenya, calculated that
Uganda was releasing about twice as much water as is allowed under the agreement
and was the primary culprit in recent drops in the lake's level. At 55,372 cubic meters
per second, more than double the maximum agreed curve, it would take a year to drain
110.75 cubic kilometres from the lake. That is approximately 4% of the lake's volume.
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Since the 1900s Lake Victoria ferries have been an important means of transport
between Uganda, Tanzania and Kenya. The main ports on the lake are Kisumu,
Mwanza, Bukoba, Entebbe, Port Bell and Jinja. The steamer MV Bukoba sank in the
lake on October 3rd, 1995 with a loss of nearly 1,000 lives in one of Africa's worst
maritime disasters.
The water lily (water hyacinth), a native of the tropical Americas, was introduced by
Belgian colonists to Rwanda to beautify their holdings. It then advanced by natural
means to Lake Victoria where it was first sighted in 1988. There, without any natural
enemies, it has become an ecological plague, suffocating the lake, diminishing the fish
reservoir, and hurting the local economies. By forming thick mats of vegetation it
causes difficulties to transportation, fishing, hydroelectric power generation and drinking
water supply. By 1995, 90% of the Ugandan coastline was covered by the plant. With
mechanical and chemical control of the problem seeming unlikely, the mottled water
hyacinth weevil (Neochetina eichhorniae) was bred and released with good results. On
the Kenyan site, however, neglect has led to significant economic impact making it
difficult to reach the harbour of Kisumu, hurting fishing, and threatening the water
supply.
The situation in Lake Nakuru is nothing better. Approximately 50,000 inhabitants of
Nakuru town pour some 1.1 million gallons of partially treated sewage into the shallow,
18-square-mile lake every day. Between the town and the lake is a vast city dump
where everything from junked automobiles to garbage rots, slowly feeding a modern
array of synthetic chemicals into the soil where rainwater flushes it into the lake. When
garbage is burning, a pall of acrid smoke hangs over the area. On other days, countless
toxic chemicals leech unseen into the ground, eventually to reach the lake. To the east,
south and west of the lake is agricultural land where DDT, Dieldrin and a host of other
pesticides are widely used. These too find their way into the lake and, according to
scientists, may soon reach levels that could wipe out much of the bird life.
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At the current rates of input, the concentration of pesticides in the lake is likely to
increase tenfold in 15 years. The Environmental Pollution Research Unit of the Kenya
National Parks estimates, however, that before then the fish and flamingos would be
dead. Already a few pelicans are dying from what is believed to be the combined
effects of several toxic chemicals each of which exists in sub-lethal levels.
One of the world's most beautiful natural habitats is taking the brunt of the water
pollution, pesticide pollution and solid waste pollution of a town growing at an annual
rate of 6.8 percent and an agricultural region that must feed the increasing millions of
Kenyans who live in arid parts of the country. Yet Lake Nakuru is also the scene for one
of Kenya's first and most ambitious environmental monitoring programs. It is an effort
that could become the prototype for an ecological early warning system to be used
throughout Africa.
Prevention of this result appears difficult at best. To suggest that Kenyan farmers
sacrifice productivity by cutting back on fertilizer and pesticides would only shift the
suffering from birds to people. However, much could probably be achieved by
agricultural extension programs to teach more efficient use of fertilizers which are often
applied at the wrong times and in the wrong ways. More crucial however, is the use of
pesticides. Although some of this could be cut down by similar more efficient methods,
the main problem is more basic.
When the U.S. and other industrialized countries banned the use of DDT, many
manufacturers stepped up efforts to sell off huge stocks in the "underdeveloped" world.
DDT was already attractive to African farmers because of its low cost and high
effectiveness. In a continent beset with famine, it is not easy to argue that food
production should be sacrificed now to protect the health of generations yet unborn.
In the same way, it is difficult to suggest that with unemployment rates of 20 to 30
percent in the cities, the pace of industrialization should be slowed by the insistence on
expensive pollution controls.
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Few people here argue that stiff pollution controls should be imposed now. Rather they
suggest a compromise that involves monitoring the pollution (the Nakuru research is
the prototype) until it reaches the danger level and then doing something about it.
Idealistic Americans often say to Kenyans, "You got a beautiful country. You should
start now to protect it. You should learn from our grave mistakes in the United States."
Kenyans almost invariably reply something to the effect of, "Lets trade places. Give us
your standard of living and we'll take your pollution too."
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CONCLUSION
THE WAY FORWARD TOWARDS THE FUTURE
Kenyans have resolved to embark on the following measures to ensure conservation of
our lakes for sustainable utilization in the future;
(a) Protection of the habitat of globally significant biodiversity because of improved land
and water management;
(b) Increased awareness and understanding of conservation of biodiversity through
sustainable natural resource management;
(c) Development of replicable models for community-based conservation of biodiversity
of global importance.
(d) Improved collaboration between local authorities, communities, and NGOs on
biodiversity conservation;
(e) Empowered local communities capable of addressing land and water management
issues in an integrated manner;
(f) Protection of endangered habitats for grazing herbivores and migratory birds;
(g) Improved technical capacity of local authorities to support community based
enterprises;
(h) Improved capacity (technical and financial) of NGOs and community groups to
ensure long-term conservation of the lakes area; and
(i) Dissemination of lessons learned to other projects, including the "Conservation and
Sustainable Use of Biodiversity in the Eastern Rift Valley Lakes which is currently
under preparation with GEF
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The baseline actions focus on achieving sustainable land management in the following
ways:
(a) Demonstration projects on high-yielding pasture and fodder production;
(b) Afforestation and re-afforestation
(c) Establishment of a nature reserve;
(d) Awareness environmental education for local communities; and
(e) Alternative livelihood for local people, especially women.
These efforts are likely to succeed because of:
(a) High political commitment;
(b) Major local government and community involvement in project development and
implementation; and
(c) Establishment of conservation-based enterprise as an incentive to raise awareness
among the intended beneficiaries about the ecological and financial benefits
associated with improved conservation of natural resources.
The alternative actions are:
(a) Promotion and adoption of integrated approaches to land and water management;
(b) Wildlife conservation activities;
(c) Provision of environmentally sensitive economic activities for the local people as a
means to reduce pressure on biodiversity/natural resources.
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REFERENCE
Blackwell, Basil. (1987) UNEP Environment Data Report 2nd Edition U.K.
Encarta, Encyclopedia. (1988) Encyclopedia Encarta Inc. USA.
Korir Koech (Dr)..
(1988) Environmental Education Kenyatta University, UON
Printing Press, Nairobi.
Swan, J.A et al. Environmental Education Strategies towards a more reliable
future.
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