Tanzania’s Lake Natron has a killer reputation. Said to turn local wildlife to stone, its bright red waters certainly seem to signal danger. But in fact, the concentration of harmful chemicals in this alkaline lake supports a rich ecosystem. The water of Lake Natron reaches scalding temperatures of more than 40°C (104°F).
Fed by hot springs, Lake Natron’s waters are warm and rich in minerals. These chemicals are so concentrated that the lake is highly alkaline – with a pH level of 10, it is the most caustic body of water in the world (capable of burning the eyes and skin of creatures that are not adapted to it). The lake takes its name from natron (hydrated sodium carbonate), which is left as a salt deposit when lake water evaporates.
Despite the dangers, about 2.5 million lesser flamingos nest on Lake Natron, making it one of the largest breeding grounds for this African species. They build their nests on small islands that form in the lake during the dry season, and feed on the plentiful algae inhabiting the waters.