Emily Chan
Dozens of rivers in Alaska have suddenly turned orange, and climate change may be to blame. The orange water could have a negative impact on local wildlife populations.
According to a study published in the journal Communications Earth and Environment, at least 75 rivers have changed color since 2017.
The phenomenon is due to the thawing of permafrost. Permafrost is soil or underwater sediment that remains completely frozen for at least two years straight.
The soil in Alaska contains several metals, such as zinc, cadmium, copper, iron, arsenic, and lead. The warming climate causes the permafrost to melt at rapid rates so that the metals have entered Alaska’s once-clear waterways. Metals like iron have a chemical reaction with oxygen in the water, which turns the water orange.
Additionally, the number of affected rivers and streams seems to be going up. The first observation of orange water was recorded between 2017 and 2018.
Since then, researchers from the University of California, Davis, the U.S. Geological Survey, and the National Park Service have spotted 75 waterways tinged with various shades of orange.
“Orange streams have been observed across much of northern Alaska, spanning traditional territories of the Alaska Native peoples in the Noatak, Kobuk, and Koyukuk River basins; public lands; designated wilderness; and within watersheds of several National Wild and Scenic Rivers, including the Alatna, John, Koyukuk, Tinayguk, and Salmon rivers,” wrote the authors of the study.
The phenomenon is a threat to all species in Alaska, impacting everything from fish to drinking water.
Fish in Alaska are important for sustenance, sport, and commercial fisheries, but the excess of iron and other toxic metals in the water may decrease the quality of the water and reduce habitat.
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