The Alarming Color Shift in Alaska’s Pristine Waters

Dozens of rivers in Alaska are turning from pristine and clear blue to a worrying shade of rusty orange.

According to The Guardian on the 22nd (local time), a research team from the University of California, Davis published the reason in Nature, explaining the cause of this phenomenon is due to rising temperatures in the Arctic causing ice to melt.

The team explained that melted permafrost releases minerals such as iron, copper, zinc, and cadmium in the soil.

These minerals react with oxygen as they dissolve into the river water, changing the color of the water significantly enough to be noticeable even in satellite photos. The Arctic is the fastest region that is affected by global warming.

Professor Brett Poulin, who led the research, expressed concern, saying, “We are currently witnessing unexpected results of climate change in some of our country’s cleanest rivers. If these rivers mix with others, the minerals could have a stronger impact on the aquatic ecosystem.”

The phenomenon of rivers turning orange was first observed in 2018. At that time, scientists discovered that the rivers in the northern Brooks Range of Alaska had turned a light orange color, completely different from their previous crystal blue hue. Within a year, two native fish species completely disappeared from the tributaries of the Aichilik River in the Kobuk Valley National Park.

Poulin explained, “Our investigation revealed that when the river water turns orange, there is a significant decrease in large invertebrates and biofilms, the essential foundation of the food chain in the riverbed. This phenomenon can alter the habitat of fish species.”

Rusting is typically considered a seasonal phenomenon that occurs during the height of summer in July and August when even the deepest parts of the soil melt.

However, with this phenomenon now being observed in permafrost regions including Alaska, Canada, and Russia, scientists plan to research to accurately determine its long-term effects.

Scott Zolkos, an Arctic researcher at the Woodwell Climate Research Center, said, “This region is warming at least two to three times faster than the rest of the planet. We expect this type of change to continue.”