The high concentrations of salts make Lake Natron inhospitable to many plants and animals. Found in an arid climate in Tanzania, the lake receives only about 500 millimeters (20 inches) of rain during non El Niño years. Another incoming source of water to the 60 kilometer long lake is the Ewaso Ng’iro River. Hot springs channel sodium carbonate and calcium carbonate salts into the lake from nearby volcanoes such as Ol Doinyo Lengai (about 20 kilometers to the south).
The high rates of evapotranspiration have resulted elevated amounts of natron (sodium carbonate decahydrate) and trona (sodium sesquicarbonate dihydrate) in Lake Natron. It’s within these saline waters that halophile (salt-loving) organisms thrive, including cyanobacteria that produce the red and pink pigments that color the lake.
It’s the protective salt marshes that ring the lake that provide habitat and food in the form of spirulina (a green algae with red pigments) that has nurtured the highest concentrations of lesser and greater flamingos in East Africa. The receding waters of the lake during the dry season provide ideal nesting conditions for lesser flamingos. Lake Natron is the only regular breeding grounds for the lesser flamingos, a threatened species. The current population of around 2.5 million is the largest single flock of birds in East Africa.
