Lake Natron

The lake Natron is a Lac salted endoreic Alcali N of origin Tectonique whose variable surface confines it in the north of the Tanzania or makes him episodically cross the border with the Kenya. Its water charged with Micro-organisme S attracts an important community of dwarf flamingos which regales blue algas and which reproduce there and there nidifient.

The lake draws its name from the Natron, a Minéral of which one of the components, the Bicarbonate of soda, is dissolved in great quantity in its water.

Characteristics

Located at the extreme North of the Tanzania, in the North-West of the Mont Froze, in the north of the Ol Doinyo Lengaï pertaining to the Massif of Ngorongoro and in the south-west of the Lac Magadi, the lake Natron is placed in a depression lengthened, directed North-South, delimited by two Horst S and included in the Eastern branch of the Vallée of the great rift. Far from deep (approximately three meters), the lake is endoreic. Its contributions out of water are due only to the Précipitation S which fall directly into the lake or which feed some rivers which throw to it like the river Ewaso Ng' iro coming from the south. Thus, its surface, its depth and its volume strongly vary between the rain season and the Saison dries, the lake which can cross the border with the Kenya in north when it reaches its maximum surface.

Formerly filled of an abundant fresh water, this lake evaporated with the wire of the millenia until not exceeding 3 m of depth more today.

The lake Natron behaves like immense a natural saltworks. Indeed, its water is very Alcali born with a variable pH between 9 and 10,5 (that is to say almost as much as the Ammoniaque) and is very charged in salts of which Bicarbonate of soda which gives its viscous consistency to water. When the rains increase the quantity of water contained by the lake, the alkalinity and the salt concentration of water decrease. But when the rains cease feeding the lake and that the temperatures increase up to 50 °C, strong the evaporation, in addition to involving a fall of the depth, volume and surface of the lake, increases the alkalinity of water and concentrates the chemical elements up to the point of saturation which causes to them precipitation. These salts then form crusts and platforms blanchâtres sometimes coloured in pink-red by watery micro-organisms.

Fauna and flora

In spite of the relatively hostile environment which reigns there (strong heat, water basic and charged in salts), the lake Natron is not deprived of life. Indeed a species of Poisson, the alkaline tilapia ( Oreochromis alcalica ), saw there just as watery Micro-organisme S Halophile S like cyanobacteries and Spiruline S which give their color pink-red to water and the salt deposits.

The lake Natron constitutes also the most important place of reproduction and nesting permanent of East Africa for the dwarf flamingos with a population which can reach 2,5 million individuals. The largest gatherings are reached when water of the lake sufficiently evaporated to obtain a concentration raised in spirulines whose nourish themselves the dwarf flamingos. In addition to the fact that these birds are not inconvenienced by the living conditions near the lake and that they find there a source abundant of food, water Alcali born from the lake their offers a natural protection against the Prédateur S which cannot venture to the birds or with their nests.

In addition to the dwarf flamingos, the lake constitutes also a place of temporary or permanent life for 100.000 other water birds.

Population

Although Masaï S live breeding as a practitioner the semi Nomadisme with the accesses of the lake, no important city is located in the area.

Protection of the lake

The Salinité of water of the lake is endangered by the Déforestation at the Kenya and the construction of a hydroelectric factory on the river Ewaso Ng' iro in Tanzania which are likely cause a drop in the concentration in salts lake. Moreover, the current Climate warming world threatens it of temporary and permanent in the long term drying by rarefaction of the rains and excessive evaporation.

The site of the basin of Natron which includes the lake was classified site Ramsar on July 4th, 2001 because of its environment and its single fauna.

See too

List of the Tanzania Lakes

External bonds

NASA - the lake Natron seen of space

Source

LakeNet - Lake Natron

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