Rivers and streams in Alaska are changing color, from a clean, light blue to a rusty orange, due to toxic metals released by thawing permafrost, according to a new study.
The finding surprised researchers from the National Park Service, the University of California, Davis, and the U.S. Geological Survey, who conducted tests at 75 locations in Alaska's Brooks Range waterways. The mountain range's rivers and streams appeared to rust and turn murky and orange over the past five to 10 years, according to the study published in the journal Communications: Earth & Environment.
The discoloration and cloudiness are caused by metals such as iron, zinc, copper, nickel and lead, researchers found, some of which are toxic to river and stream ecosystems as permafrost melts and exposes waterways to minerals locked underground for a long time, thousands of years.
Studies have shown that the Arctic is warming four times faster than the rest of the world.
"What we think we're seeing is this ground melting that's happening faster there than other places," said Brett Poulin, a co-author of the study and a professor of environmental toxicology. at the University of California Davis. "It's really an unexpected consequence of climate change."
