Tanzania Halts Major Soda Ash Mine to Protect Lake Natron Ecosystem

Lake Natron, a terminal basin situated in northern Tanzania near the Kenyan border, is defined by its striking crimson coloration and intensely alkaline waters, a geological feature estimated to have formed over 1.5 million years ago. This unique chemistry is sustained by tectonic activity within the East African Rift System, with the nearby stratovolcano Ol Doinyo Lengai supplying sodium carbonate via subsurface hot springs. The lake’s environment is characterized by summer water temperatures that can reach 60°C and a pH level fluctuating between 10.5 and 12, a corrosiveness comparable to household bleach solutions.

The extreme chemical composition supports specialized life, including haloarchaea and cyanobacteria, which generate the water’s vibrant red hue. While lethal to most organisms, the high sodium carbonate concentration acts as a natural preservative, leading to the calcification of desiccated remains rather than instantaneous petrification. The lake's hydrology is maintained by seasonal inflows, such as the Southern Ewaso Ng'iro River, and hot springs, with evaporation rates calculated at eight times the localized annual rainfall of approximately 400mm. Migrating birds are sometimes disoriented by the water’s reflective surface, leading to fatal encounters with the caustic environment.

Designated a Ramsar Site of International Importance in 2001, Lake Natron serves as the sole reliable breeding ground in East Africa for the Lesser Flamingo (Phoenicopterus minor), classified as 'Near Threatened' by the IUCN. The cyanobacteria blooms provide the essential food source for millions of these birds, which typically nest between August and October on salt islands that are naturally protected from mammalian predators by the caustic water. Furthermore, endemic fish species, including Alcolapia latilabris and Alcolapia ndalalani, have adapted to survive in the lake's less concentrated margins.

In a significant conservation measure, the Tanzanian government announced in August 2025, via Deputy Minister for Minerals Stephen Kiruswa, that it had halted a large-scale soda ash mining project proposed by Ngaresero Valley Company Ltd. The proposal sought to extract up to 1,000,000 metric tonnes annually. Conservationists and local Maasai communities had warned that the project risked irreversible damage by altering the lake’s delicate hydrology and displacing an estimated 65,000 pastoralists dependent on the area for grazing and tourism.

The decision to block industrial extraction, while allowing traditional, small-scale surface collection of soda ash, prioritizes the lake's critical ecological function. This action supports the continued role of Lake Natron as the breeding ground for up to 75 percent of the world's Lesser Flamingo population, aligning with the positive economic impact of ecotourism initiatives established in local villages like Engaresero since 2008.