A new study has revealed that dozens of rivers and streams in Alaska are turning a rusty orange color due to the thawing permafrost, a consequence of climate change. The Arctic region, known for its rapid warming, is witnessing the release of minerals previously locked away in the frozen ground, which are now seeping into waterways.

The research, conducted by Brett Poulin, an assistant professor of environmental toxicology at the University of California Davis, highlights the unforeseen impacts of climate change on some of the country's most pristine rivers. As permafrost thaws, minerals in the soil are exposed to oxygen, causing a process known as weathering. This weathering increases water acidity and dissolves metals such as zinc, copper, cadmium, and iron. Iron is the most visible metal, giving the rivers a distinctive rusty color even visible from satellite images.

This phenomenon poses significant risks to both drinking water quality and fisheries in the Arctic. Poulin noted that the mixing of the rusty rivers with other water sources could even make the metals more potent in their impact on aquatic health.

The rusty rivers first came to attention in 2018 when researchers observed the milky orange appearance of rivers across Alaska's Brooks Range. This stark contrast to the previously clear waters raised concerns about the potential implications for the food web and the habitats of fish.

The rusting of the rivers is a seasonal occurrence, typically happening in July and August when the soil is thawed at its deepest. Poulin and his research team, in collaboration with the National Park Service, US Geological Survey, and the University of California Davis, aim to understand the long-term consequences of changing water chemistry in areas with continuous permafrost. These regions include Alaska, Canada, Russia, and parts of Scandinavia.

Scott Zolkos, an Arctic scientist at Woodwell Climate Research Center, who was not involved in the study, highlighted that the Arctic is warming two to three times faster than the rest of the planet. He emphasized the need to expect similar effects to continue in the future.

Recognizing the importance of accurate information dissemination, the research group is closely working with tribal liaisons in Alaska to ensure that local communities receive updated information about this ongoing phenomenon.

Further research and understanding of the impacts of thawing permafrost on water chemistry will be crucial in mitigating and adapting to the changing climate in the Arctic region.