Dozens of once-clear streams and rivers in Arctic Alaska now run bright orange, cloudy, and possibly more acidified. It looks like an industrial mine has been running for decades, and scientists want to know why.
Roman Dial, a professor of biology and mathematics at the University of Alaska Pacific, first noticed a drastic change in water quality during fieldwork in the Brooks Range in 2020. He spent a month with his team of six graduate students, but not enough drinking water. “There are so many streams that are not only dirty, but so acidic that they curdle formula,” he said. I couldn’t drink it because of the mineral taste and pungency.”
Exploring the Arctic for the past 40 years, Dial has collected data on changes in Alaska’s treeline due to climate change. The project also includes the work of ecologist Patrick Sullivan, director of the University’s Environmental and Natural Resources Laboratory. Becky Hewitt of his Anchorage, Alaska, professor of environmental studies at Amherst College. Now the team is delving into the mysteries of water quality. “It’s like being a graduate student again in a lab you know nothing about, and that fascinates me,” he says.
Most of the Rusted Channels are located in some of Alaska’s most remote protected areas. Arctic National Wildlife Refuge, Arctic National Park Gates and Reserves, Kobuk Valley National Park, Selawik Wildlife Refuge.
This phenomenon is visually striking. “It looks like something was broken open or exposed in a way that has never been exposed before,” Dial said. “Every Hard Rock geologist who sees these pictures says, ‘Oh, that looks like acid mine waste.'” But it’s not mine waste. Researchers say the rusty coating on rocks and riverbanks comes from the land itself.
A leading hypothesis is that climate warming is causing the underlying permafrost to degrade. Iron-rich sediments are released, and when those sediments hit running water or the outdoors, they oxidize and turn a deep rusty orange. Oxidation of minerals in the soil can also increase water acidity. there is. The research team is in the early stages of the process of identifying the cause to better explain the results. I was. Although pH regulates many biological and chemical processes in streams and rivers, its exact effects on the complex food webs that exist in these waterways are unknown. From fish to bed bugs to plant communities, the researchers aren’t sure what changes will occur.
Alaskan river rust can also affect human societies. Rivers such as the Kobuku and Ulik rivers where rusting has been observed also serve as drinking water sources for many Alaska Native communities in northwestern Alaska. According to Sullivan, if water quality continues to deteriorate, a major concern is how it will affect the species that are the primary source of food for Alaska Natives, who live subsistence lifestyles. It’s one.
The Ulik River ends at the village of Kivalina, a community of just over 400 people located 80 miles north of the Arctic Circle. This village depends on the river. “We are always worried about drinking water,” said Tribal Administrator Millie Hawley, adding in a written message that her friends and neighbors fish for trout in the river year-round. The community has seen the river become increasingly muddy in recent years, she said, with some blaming the nearby Red Dog mine. , said that everyone is aware that increased erosion is increasing the levels of dissolved minerals and salts in Ulik.
In addition to current influences, researchers also consider historical records. “It certainly happened[before],” Dial said. “Because, in a way, this is a natural phenomenon.” But Dial and Sullivan note that the rate of climate warming is greater than ever recorded. “So it’s very possible that something like this has happened before, but it happened very slowly. And all that was hoisted up in these streams was this massive orange pulse. Maybe it wasn’t,” said Sullivan.
The team believes there may be multiple factors associated with climate change. Both 2019 and 2020 – his two hottest summers on record – were followed by a winter of unusually high snow cover. “Snow is an excellent insulator for soils and can be a powerful catalyst for permafrost thaw,” Sullivan said. He likens it to adding a blanket before the ground freezes. So far, no researchers know for sure whether orange streams and rivers are anomalous events. And only time will tell how long it will last.
This article originally appeared in High Country News and is republished here with permission.
Emily Schwing is an Alaska-based reporter. find her on her twitter @emilyschwing. Email high country news At firstname.lastname@example.org or submit a letter to the editor. See Letter to Editors Policy.