Alaska rivers change color due to minerals released by melting snow
by Andreína Barreto Jové, Huella Zero
Release of metals due to thawing permafrost could harm drinking water quality and fisheries in Arctic watersheds.
A report published by Nature magazine warned that rivers and streams in Alaska are changing their natural blue color to orange, due to the release of minerals from thawing permafrost: one of the largest reserves of organic carbon dioxide on the planet.
The study was conducted in conjunction with researchers from the National Park Service; the United States Geological Survey, and the University of California, Davis. These institutions documented and sampled at least 75 locations in the northern Brooks Range of Alaska.
Waters affected by toxic metals are located in federal lands managed by the Bureau of Land Management, the Fish and Wildlife Service, and the National Park Service, including the Gates of the Arctic and Kobuk Valley national parks, and could affect drinking water and fisheries in Arctic watersheds.
Brett Poulin, associate professor of environmental toxicology at the University of California, said that the now orange rivers of Alaska “are so large and pigmented” that they can be seen from space. Experts blame the thawing of permafrost, with approximately 1.5 billion tons, due to the amount of minerals it contains. As the planet warms, metals and acids are released. “What we are seeing in this ground thaw is happening faster than it would happen anywhere else. “It’s really an unexpected consequence of climate change,” Poulin said.
Minerals released into the water The scientists showed that some of the contaminated water contained a pH of 2.3, rather than the average pH of 8 for rivers and streams. This involves the erosion of sulfide minerals, causing more acidic and corrosive conditions that release additional metals, including zinc, iron, nickel and copper. “We see many different types of metals in these waters. One of the most dominant metals is iron. “That’s what’s causing the color change,” said researcher Taylor Evinger. Additionally, they warned that Alaska is not the only state in the US to experience this phenomenon. The Colorado Rockies have recorded similar effects on changing water color.
Background on Alaska rivers The report noted that Jon O’Donnell, an ecologist with the National Park Service’s Arctic Inventory and Monitoring Network, reported in 2018 a change in the appearance of the waters, according to satellite images. “The problem is slowly spreading from small headwaters to larger rivers over time. When emerging problems or threats arise, we have to be able to understand them,” O’Donnell said.
The expert agreed with Poulin and Evinger that water quality could be affected, as well as other ecological systems. The fish population can be seen decreasing.