The red accessory photosynthesizing pigment in the cyanobacteria produces the deep reds of the open water of the lake and the orange colors of the shallow parts of the lake. The alkali salt crust on the surface of the lake is also often colored red or pink by the salt-loving microorganisms that live there.

Is Lake Natron always red?

Lake Natron, Tanzania.

The color varies from orange to red, to pink and is produced by the bacterias and other microorganisms. Surprisingly, this lake is a habitat for flamingos, that nest here and feed on red algae despite the alkaline water.

Why is the water on Lake Natron dangerous?

The alkaline water in Lake Natron has a pH as high as 10.5 and is so caustic it can burn the skin and eyes of animals that aren't adapted to it. The water's alkalinity comes from the sodium carbonate and other minerals that flow into the lake from the surrounding hills.