Lake Natron

Lake Natron is a unique, highly saline lake located in northern Tanzania, close to the border with Kenya. It’s situated within the East African Rift Valley, an area of volcanic activity and geological wonder, which shapes the lake’s remarkable chemical composition. Known for its striking red and orange hues, which come from salt-loving microorganisms, Lake Natron stands out in the region as one of the most extreme environments on Earth. Its water can reach temperatures as high as 60°C (140°F) and has a pH level between 9 and 10.5, creating an inhospitable habitat for most forms of life. However, its harsh conditions support a unique ecosystem that has evolved to thrive in the lake’s waters.

The lake’s high alkalinity comes from the mineral-rich volcanic ash that is washed into the lake from nearby volcanoes, most notably Ol Doinyo Lengai, a sacred mountain for the Maasai people and the only active carbonatite volcano in the world. This alkaline environment is particularly suited to the growth of cyanobacteria, a type of salt-loving microorganism that produces red pigments when exposed to intense sunlight. These microorganisms, in turn, tint the water in vivid shades of red and orange. The coloration is most pronounced during the dry season when water levels are low, creating an otherworldly landscape.

Despite its inhospitable conditions, Lake Natron is a vital sanctuary for the lesser flamingo (Phoeniconaias minor). This flamingo species, listed as “near threatened,” relies heavily on Lake Natron as a breeding ground. The flamingos nest on the lake’s salt-crusted islands, where they are largely safe from predators due to the lake’s caustic waters. During the breeding season, Lake Natron supports over 2 million flamingos, which feed on the lake’s cyanobacteria. Their bright pink coloration is partly due to the beta-carotene in their diet, derived from these microorganisms. This breeding behavior makes Lake Natron a crucial habitat for the survival of the species.