A study published in the journal Limnology and Oceanography concluded that the waters of the Rocky River are so dark because they barely hold sediment due to the gentle slope of its bottom, but they contain a large amount of dissolved organic matter.
The Rocky River may easily be the darkest river in the world.
Its water contains four times more organic carbon compounds than the Congo River, and one and a half times more than its Amazon tributary, the Río Negro.
According to the researchers, carbon-containing materials enter the river mainly with rainwater. The study showed that rainfall in the forest releases organic compounds from dead plants.
Rocky River is a “jungle tea”
The river also floods the forest during the rainy season. In this case, water often stands at waist level in the forest for weeks and flows only very slowly. This process also enriches the river water with organic materials. Rocky is actually a “jungle tea,” Travis Drake, a researcher at ETH Zurich, said in the university’s announcement.
The kilometer-wide Rocky River flows into the Congo. Its watershed area is four times the size of Switzerland, and is covered by lowland rainforest. There are large peat bogs along the river, which absorb carbon dioxide significantly due to dead but not decomposing plant material, MTI reported.
Seasonal water level data in the Rocky River has been recorded since the 1930s, but no scientific research has been done on it yet, so the chemical composition of the water was also analyzed for the first time in the study led by the Swiss.
