Dozens of rivers and streams in Alaska are turning rusty orange. This is likely due to the thawing of permafrost, also known as "permafrost," says a new study cited by Guardian.
The Arctic (Earth's northern polar region, encompassing the edges of the Eurasian and North American continents) is the fastest-warming region on the globe, and as the frozen ground beneath the surface melts, minerals that were once locked in that soil are now seeping out. in waterways.
"This is an unintended impact of climate change that we're seeing in some of our nation's most pristine rivers," said Brett Pullin, study author and assistant professor of environmental toxicology at UC Davis.
Thawing permafrost exposes minerals to oxygen in a process known as weathering, which increases the acidity of the water and dissolves metals such as zinc, copper, cadmium and iron—the most obvious metal that gives rivers a rusty color visible even in satellite images. The study highlights the potential deterioration of drinking water quality and the risk to Arctic fisheries.
"When mixed with water, metals become even more powerful in terms of their impact on the health of the aquatic environment," Poulin said.
The "rusting" phenomenon
The phenomenon was first observed in 2018, when researchers noticed the milky orange appearance of rivers in the Brooks Mountains of northern Alaska, a stark contrast to the crystal clear waters observed the previous year.
Within the year, two native species of fish completely disappeared at a tributary of the Akilik River in the Kobuk Valley National Park.
"When the river turns orange, there's a significant reduction in macroinvertebrates and biofilm on the bottom of the stream—essentially the base of the food web," Poulin says of the rust phenomenon.
"Rust" is a seasonal phenomenon that occurs in the summer, usually July and August, when the soil is most deeply thawed. Researchers from the National Park Service, the US Geological Survey and the University of California, Davis now want to better understand the long-term consequences of changing water chemistry in places with continuous permafrost, which includes Arctic regions such as Alaska, Canada, Russia and parts of Scandinavia.
"This is an area that is warming at least two to three times faster than the rest of the planet. So we can expect these types of effects to continue," said Scott Zolkos, an Arctic scientist at the Woodwell Climate Research Center who was not involved in the study.
The research group said it is working closely with Alaska Natives to ensure local communities receive accurate information about the developing phenomenon.