10/05/2026
We are in so much trouble...
https://www.facebook.com/share/p/1ByF2NVNVf/
Some of Alaska’s clearest Arctic rivers are turning orange, and researchers say the cause is thawing ground, not nearby mining.
A new AGU Advances study found that acidic runoff raised some metal concentrations in the Salmon River to as much as 70 times upstream levels, with elevated concentrations persisting more than 60 miles downstream.
Researchers led by UC Davis sampled six watersheds across Alaska’s Brooks Range during the summers of 2022 to 2024. They investigated orange streams and hillside seeps in remote areas without nearby mines, yet some samples resembled severely polluted mine drainage.
The process begins with permafrost, ground that remains frozen for at least two consecutive years. As it thaws, water can move deeper into the ground and reach minerals that were previously isolated. Sulfide minerals can react with oxygen and water, generating acidity and releasing metals such as iron, aluminum, manganese, zinc, nickel, and cadmium into streams.
The orange color comes largely from iron-rich particles forming in the water, similar to rust. Other metals can remain dissolved and travel beyond the visible staining.
Researchers traced abrupt chemical changes to 2019 and 2020, following unusually warm conditions and heavy winter snowfall. Snow can insulate the ground, slowing the release of heat during winter and helping prolong thaw.
The impacts were not the same everywhere. Larger river channels buffered much of the acidity and kept pH relatively stable, even as metal concentrations increased. That matters because water can appear less acidic while still carrying metals.
The team has not identified widespread fish deaths or drinking-water harm to villages from the studied streams, but the findings raise concerns for aquatic ecosystems and for Arctic communities, including Alaska Native communities, whose foodways, travel, and cultural practices are closely tied to rivers.
What kinds of monitoring or local knowledge partnerships would help communities better understand changes in Arctic rivers?
Sources: Earth and Planetary Sciences, Protect Our Winters, Thinc, ONE Only Natural Energy, SEJ, Alaska Native News