The Amazon River flows for more than 4,100 miles (6,600 km); within its hundreds of tributaries and streams are the largest number of freshwater fish species in the world.
Bacteria living in the Amazon River can digest woody materials shed by the surrounding rain forest by turning these pieces of tree bark and stems into carbon dioxide as they are washed down the river, according to a new study. The findings bolster the Amazon basin's reputation as being the lungs of the planet, taking in carbon dioxide and releasing oxygen, but show that the carbon dioxide doesn’t necessarily stay trapped in the trees.
Researchers at the University of Washington found that bacteria in the Amazon River can break down almost all of the tree and plant materials in the water, and this process is a major generator of the carbon dioxide breathed by the river.
"Rivers were once thought of as passive pipes," study co-author Jeffrey Richey, a professor of oceanography at the University of Washington in Seattle, said in a statement. "This shows they're more like metabolic hot spots." [The World's Longest Rivers]
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