Nick Brandt, well-known for his photography of East Africa's natural landscape, came across Tanzania's Lake Natron during his travels.
The lake is named for a mineral (natron, often referred to as sodium carbonate decahydrate) whose presence gives Lake Natron a unusually high alkaline content. With a severe alkalinity pH that ranges from 9 to 10.5, and water temperatures that can reach 140 degrees Fahrenheit, the lake is so inhospitable that it kills most wildlife that wind up in its depths.
The lake's unique chemical composition calcifies living creatures like birds or bats, yielding faultlessly preserved specimens whose washed up bodies remain dotted along the lake's environs. According to The New Scientist, Brandt stumbled upon the calcified creatures in these very positions, collected them, and then placed their bodies on branches to create his eerie portraits.
Unless you are an alkaline tilapia (Alcolapia alcalica) – an extremophile fish adapted to the harsh conditions – it is not the best place to live. During the dry season, Lake Natron’s high pH levels are just below ammonia on the scale of caustic substances.
This makes the lake highly corrosive, and contributes to the “stoning” of so many birds and mammals that fall victim to the water. The mineral content can get so high that the water feels “thick” to the touch. Theories suggest the animals are muddled by the glassy surface of the lake and get trapped there, slowly calcifying because the water is so “heavy” they cannot escape once they come in contact with it.
The lake is fed by a river and mineral hot springs in the area, but has no outlet, so these waters have nowhere to go but up. Evaporation of the surface creates islands of exposed salt deposits in the lake, some large enough to be recorded on satellite images.