Many of the once-clear rivers and streams in Arctic Alaska are turning orange and cloudy. In some cases, it may even be becoming more acidic. Scientists want to understand why this otherwise undeveloped landscape looks so much like an industrial mine.
Roman Dial, an Alaska Pacific University professor of biology, and mathematics, noticed the most drastic changes in water quality while fieldwork in the Brooks Range in 2020. A group of six graduate students accompanied him for a month and could not find enough water. He said that there are many streams that aren’t just stained but so acidic that they can curdle powdered milk. Others had clear water, but it was hard to drink because of its strange mineral taste.
Dial, who has spent the last 40 years exploring the Arctic, was gathering data on climate-change-driven changes in Alaska’s tree line for a project that also includes work from ecologists Patrick Sullivan, director of the Environment and Natural Resources Institute at the University of Alaska Anchorage, and Becky Hewitt, an environmental studies professor at Amherst College. The team is now investigating the mystery of water quality. Dial stated, “I feel like a graduate student in a lab I don’t understand anything about and I’m fascinated with it.”
The majority of the rusting waterways can be found within Alaska’s most remote protected areas: the Arctic National Wildlife Refuge and the Gates of the Arctic National Park and Preserve as well as the Kobuk Valley National Park and the Selawik Wildlife Refuge.
This phenomenon is quite striking visually. Dial stated that it looks like something has been opened or exposed in a way never seen before. “All the hardrock geologists that look at these photos, they are like, ‘Oh! That looks like acid mine wastewater.’ But it is not mine waste. Researchers believe that the land is responsible for the rusty coating of rocks and streambanks.
According to the dominant hypothesis, climate warming is causing the underlying permafrost layer to melt. This releases iron-rich sediments, which oxidize when they come in contact with water and air. It is possible that the soil minerals are being oxidized by the acidic water. Although the research team is still trying to identify the cause, it is not yet clear what the implications are. Hewitt stated that the pH issue — the acidity in the water — was “truly alarming.” Although pH regulates many chemical and biotic processes in rivers and streams, it is not known what impact this may have on the complex food webs found in these waterways. The research team isn’t sure what changes could occur, from fish to stream bed bugs and even plant communities.
Human communities will likely be affected by the rusting of Alaska’s rivers. Many Northwest Alaska Native communities, including those in the Kobuk, use rivers like the Wulik to get their drinking water. Sullivan said that if the water quality continues to deteriorate it could affect species that provide food for Alaska Natives who live a subsistence life.
The Wulik River ends at Kivalina, which is a small community of about 400 people located 80 miles north of the Arctic Circle that depends on the river. Millie Hawley, Tribal Administrator, said that drinking water is a constant concern. She also stated in writing that neighbors and friends fish in the river all year. She said that the river has become more turbid over the years and that some blame the Red Dog Mine nearby. Hawley stated that everyone is aware of the melting permafrost and the increased erosion that is causing the Wulik’s level of dissolved minerals to rise.
Researchers are not only looking at the current-day effects, but also the historical record. Dial said, “I’m certain it has occurred (previously),” but Sullivan and Dial note that climate warming is faster than any previous record. It’s possible that something similar has occurred before, but it happened very slowly. Sullivan suggested that maybe it wasn’t just a massive pulse of orange that ended up in these streams.”
According to the team, there may be multiple climate-related factors at work. The warmest summers of record, 2019 and 2020, were followed by snowpacks that were unusually high in winter 2019. Sullivan said that snow is a powerful insulator for soils and can drive permafrost thaw. It’s like adding a blanket to the ground to prevent it from freezing. Researchers are not sure if the orange streams or rivers are an anomaly. They occur in conjunction with a few unseasonably warm years followed by high snowpack. It is possible that it will continue for some time, but only time will tell.
Emily Schwing, a reporter based out of Alaska, is Emily. You can find her on Twitter @emilyschwing. Email High Country News to [email protected], or send a letter. Check out our policy for letters to the editor.
