Researchers from the National Park Service, U.S. Geological Survey, the University of California, Davis, and other institutions have for the first time documented and sampled some of the impaired waters, pinpointing 75 locations across a Texas-sized area of northern Alaska´s Brooks Range.

These degraded rivers and streams could have significant implications for drinking water and fisheries in Arctic watersheds as the climate changes, the experts said.

“There are certain sites that look almost like milky orange juice. Those orange streams can be problematic both in terms of being toxic but might could also prevent migration of fish to spawning areas,” lead author Jon O’Donnell, an ecologist for the NPS´ Arctic Inventory and Monitoring Network, said in a statement.

Brett Poulin, an assistant professor of environmental toxicology at UC Davis who was a principal investigator in the research, explained that they initially thought the staining looked similar to what happens with acid mine drainage, except no mines near any of the impaired rivers.

In the experts’ view, one hypothesis is that permafrost, which is essentially frozen ground, stores minerals and as the climate warmed, the metal ores that were once locked up were exposed to water and oxygen, resulting in the release of acid and metals.

“The chemistry tells us minerals are weathering, understanding what’s in the water is a fingerprint as to what occurred,” Poulin said.

Researchers measured elevated high levels of iron, zinc, nickel, copper and cadmium.

They believe the problem is growing and affecting habitat, water quality and other ecological systems, turning healthy areas into degraded habitats with fewer fish and invertebrates.

If rural communities rely on these rivers for drinking water, they could require treatment eventually, and the fishing stocks that feed local residents could be affected.

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