This story was originally Appears on Upland News and is part of Climate table cooperation.
Dozens of streams and rivers that were once clear in the Alaskan Arctic are now bright orange and cloudy, and in some cases, they are becoming more acidic. This otherwise undeveloped landscape now looks like an industrial mine that has been operating for decades, and scientists want to know why.
Roman Dial, a professor of biology and mathematics at Alaska Pacific University, first noticed the dramatic changes in water quality while doing fieldwork in the Brooks Range in 2020. He spent a month with a group of six graduate students and they could not find adequate drinking water. “There are a lot of lines out there that are not only stained but are so acidic that it solidifies your formula,” he says. Elsewhere, the water is crystal clear, “but you can’t drink it because it has a really weird mineral taste and smell.”
Dial, who has spent the past 40 years exploring the Arctic, is collecting data on climate change-induced changes to trees in Alaska for a project that includes the work of ecologists. Patrick Sullivan, director of the Institute of Environment and Natural Resources at the University. of Alaska Anchorage, and Becky Hewitt, professor of environmental studies at Amherst College. Now the team is investigating the mystery of water quality. “I felt like I was a graduate student in a lab that I knew nothing about, and I was mesmerized by it,” says Dial.
Most of the rusted waterways are in some of Alaska’s most remote protected lands: Arctic National Wildlife Refuge, Arctic Gate National Park and Preserve, Park Kobuk Valley Country and Selawik Wildlife Sanctuary.
This phenomenon is visually striking. “It looks like something has broken or something has been exposed in a way that has never been shown before,” Dial said. “All the rock geologists when they look at these photos, they say, ‘Oh, that looks like acid mine waste.’” But it wasn’t my waste. According to the researchers, the rust coating on rocks and stream banks comes from this very land.
The prevailing theory is that climate warming is causing the permafrost underneath to degrade. That releases iron-rich deposits, and when those sediments meet running water and fresh air, they oxidize and turn a deep rusty orange color. Oxidation of minerals in the soil can also make the water more acidic. The team is still early in the process of determining the cause to better explain the consequences. “I think the problem with the pH”—the acidity of the water—“is really alarming,” says Hewitt. While pH regulates many biological and chemical processes in rivers and streams, the exact impact on the complex food webs that exist in these waterways is unknown. From fish to bedbugs and plant communities, the team isn’t sure what changes might be.
The rusting of Alaska’s rivers will also likely have an impact on human communities. Rivers such as the Kobuk and Wulik, where rusting has been observed, also serve as a source of drinking water for many predominantly Alaska Native communities in Northwest Alaska. One major concern, said Sullivan, is that water quality, if it continues to deteriorate, could affect species that serve as a primary source of food for Alaska’s native residents living subsistence lifestyles.
