Lake Natron

Interesting facts

Near the lake's southern shore at Engare Sero, more than 400 human footprints left in volcanic mud between about 19,000 and 5,000 years ago are preserved.

The Engare Sero trackway is considered the largest collection of footprints of anatomically modern humans known in Africa.

In 1964 Kamoya Kimeu found the Peninj mandible west of the lake, a roughly 1.5-million-year-old jaw likely belonging to Paranthropus boisei.

The lake is up to 57 kilometres long and 22 kilometres wide, yet less than three metres deep, which is why it heats up and evaporates so quickly.

Most of its water arrives via the Southern Ewaso Ng'iro River, which rises in central Kenya, topped up by mineral-rich hot springs.

Three species of tilapia of the genus Alcolapia survive in the warm alkaline springs along its edge, and two of them live nowhere else on Earth.

Around 2.5 million lesser flamingos breed on the lake, which lies at about 600 metres above sea level in the Great Rift Valley.

A plan by Tata Chemicals to extract soda ash from the lake was shelved in 2008 amid fears for the flamingo breeding grounds.

The lake takes its name from natron, the hydrated sodium carbonate that crystallises together with trona on its shallow, evaporating surface.

Why it is worth it

Lake Natron's chemistry starts next door, at Ol Doinyo Lengai — the Maasai's 'Mountain of God' and one of the only volcanoes on Earth erupting an unusual carbonatite lava. Runoff and ash from that volcano and the surrounding rift-valley rock feed the lake with sodium carbonate and sodium bicarbonate, the same compounds ancient Egyptians used to mummify bodies. That combination pushes the lake's pH above 10 — close to ammonia — while shallow water can reach temperatures near 60°C in the sun. It is, chemically, closer to a caustic industrial solution than to a typical lake.

The blood-red color is not pollution or dye; it's biology thriving in exactly the conditions that should kill it. Salt-loving cyanobacteria and other halophilic microorganisms multiply in the alkaline brine and produce red pigments as a byproduct of their own survival — the same basic principle behind Lake Hillier's pink, just a different organism dominating a different chemical extreme. As the water evaporates and salinity concentrates further, the red intensifies.

Paradoxically, this near-uninhabitable lake is the single most important breeding site on Earth for lesser flamingos — more than three-quarters of the world's population nests here, because their chicks feed on the very cyanobacteria coloring the water, and the punishing mineral crust keeps land predators away from the nesting islands. The lake's viral fame as a lake that 'turns animals to stone' is partly real and partly staged: photographer Nick Brandt's famous images were posed using naturally calcified carcasses he found already dead on the shoreline, arranged as if alive — but the underlying process is genuine. Animals that drown here really are preserved by the same sodium carbonate that ancient embalmers relied on.

Good to know

The lake is a Ramsar-listed wetland of international importance, recognized specifically for its role as the primary breeding ground of the East African lesser flamingo population.

Best time to visit

The dry season (roughly June–October) concentrates the water and intensifies the red color, and overlaps with the peak of the flamingo breeding season (August–October).

Getting there

105 km from Mto wa Mbu. Arusha Airport (ARK) is about 127 km away.

From the encyclopaedia

Lake Natron is a highly alkaline salt lake located in north Ngorongoro District of Arusha Region in Tanzania with its far northern end crossing into Kajiado County and Narok County in Kenya. It is in the Gregory Rift, which is the eastern branch of the East African Rift. The lake is within the Lake Natron Basin, a Ramsar Site wetland of international significance.

Wikipedia · CC BY-SA 4.0