Lake Natron – Soda and Salt Lake in Tanzania

Lake Natron is a salt and soda lake in the Arusha Region of Northern Tanzania, close to the Kenyan border in Gregory Rift. The lake is mainly fed by the Ewaso Ng’iro River, which rises in central Kenya, and by mineral-rich hot springs. The water level varies depending on the source. Lake Natron is quite shallow just 9.8 feet deep, 57 KM long, and 22 KM wide.

The Natron Lake temperature is falling above 40 °C (104 °F). Due to its exclusive biodiversity, Tanzania has named the Lake Natron Basin to the Ramsar List of Wetlands of International Significance. Lake Natron is also the World Wildlife Fund East African halophytics ecoregion. Natron Lake has high levels of evaporation left behind by natron, and trona (sodium, carbonate, decahydrate, and sesquicarbonate dehydrate).

The lake’s alkalinity reaches a pH of more than 12, making the surrounding bedrock composed of alkaline, sodium-dominated trachyte lavas that were laid down during the Pleistocene period. Due to high evaporation rates, the color of the lake is characteristic during the dry season, and salinity levels rise at a certain point where the salt-loving microorganisms start to flourish.

Therefore, halophile organisms include a few cyanobacteria that make their own food with photosynthesis, as plants do. Moreover, the red accessory photosynthesizing pigment in the cyanobacteria yields the deep reds of the open water of the lake and the orange colors of the shallow parts of the lake.

The alkali salt crust on the surface of the lake is also every so often colored red or pink by the salt-loving microorganisms that live there. There are a variety of plants surrounding the lake that benefit from salt marshes and freshwater wetlands. Lake Natron is home to some endemic algae, invertebrates, birds, and fish.

Sometimes, Lake Natron temperatures cross 60 °C, making life difficult for animals and birds. The birds take advantage of the lake’s extreme conditions, which keep their predators at bay, and more than 2.5 million lesser flamingos flock there during the breeding season. Three-quarters of the world population of lesser flamingos (Hoenicopterus minor) live in East Africa and use Lake Natron as their nesting site.

Every year, countless lesser flamingos flock to Tanzania’s Lake Natron to start nesting, but this mainly depends on a combination of environmental factors. The gathering is one of nature’s fantastic spectacles. It’s a regular breeding area for 2.5 million flamingos. Who’s status is close to “near-threatened” on the ICUN Red List? These flamingos, gather along nearby saline lakes to feed on blue-green algae with red pigments, called “spirulina.”.

The high salinity & cyanobacteria support more nests; as greater flamingoes breed on mudflats, it is also a safe breeding place due to its caustic environment being a barrier against predators trying to reach their nests on seasonally forming evaporated islands. When the water level is just right, salt islands are exposed in the center of the lake, given the impeccable nesting site.

However, if the lake is too dry, predators are able to reach the young birds and eat them. If there is too much rain, the nests can be flooded. So that condition must be perfect for a successful breeding season. Moreover, there are two endemic fish species; the alkaline tilapias Alcolapia latilabris and A. ndalalani, which flourish in lake water at the edges of hot spring inlets.

The surrounding area is not inhabited, but some herding and seasonal cultivation take place. Further, there are a number of campgrounds near the lake, which is also the base for climbing Ol Doinyo Lengai. Lake Natron also provides support for 100,000 other water birds, many of whom are Palearctic migrants.

Moreover, the most interesting, strange thing about this lake is the solitary, mummified birds that can be sporadically found along its shoreline, calcified over a long period of time, and turned into fossils. The surrounding area of Lake Natron contains some of the most astonishing scenery in Africa and is also home to some wildlife, the occasional giraffe or zebra warthog, and many more.

The other attraction in the area is the mountain “Ol Doinyo Lengai”. The combination of broad open plains, sheer rift escarpments, enormous freestanding volcanoes, and the vast, multi-colored soda lake itself is home to a fascinating ecosystem. Which thrives in this severe environment is absolutely magnificent.

The construction of a dike at the north end of the lake and a planned hydroelectric power plant on the Ewaso Ng’iro in Kenya increases the threats of dilution to this breading area that may still be serious. Hence, there is no formal protection. Another big threat is a proposed plan for a soda ash plant on its shores to pump the lake water to extract the sodium carbonate to convert to washing powder. Also along with more than 100 workers housing and a coal-fired power station to provide energy for the plant complex.

In addition, there is a possibility that the developers may introduce hybrid brine shrimp to increase the efficiency of extraction. Due to these threats, the lesser flamingos continuing to breed in the face of such mayhem is next to zero and will leave lesser flamingos in extinction.

Also Read: The Alien Beauty of Socotra Island

Source: Wikipedia