Ruki, a tributary of the Congo River, has recently been dubbed the darkest river in the world, with water so dark that you can’t even see your face in front of you.
In what is considered the first-ever scientific study of the African river, scientists concluded that the dark-colored water is caused by the high levels of dissolved organic matter from the surrounding rainforest. Scientists found that the color is caused by carbon-rich compounds leached out of rotting plant matter and washed into the Ruki River by rainwater and floods. Dr Travis Drake, lead author of the recently published study, said that the Ruki is “essentially jungle tea” in which carbon-rich plant matter is brewed. The resulting coloration of the water makes the Ruki darker than the Rio Negro.
