Experts Reveal Why Alaska’s Rivers Are Turning Bright Orange and It’s More Serious Than You Think
An ecological nightmare is unfolding in the largest US state by land area, Alaska as several of its rivers turn bright orange. The alarming sight, which is also visible from space, is a matter of concern because it is turning the pristine rivers into acidic waters, potentially harming the marine and land ecosystems. In a new study published in the journal Communications Earth & Environment in 2024, scientists explained that the phenomenon was a consequence of global warming as the melting permafrost released high levels of toxic metals into the river channels imparting the orange hues.
At least 75 of the Alaskan rivers have transformed into rusty waterways in the Brooks mountain ranges of the region. Occurring beneath the surface, melting permafrost is a process in which a ground frozen for at least two years begins to thaw due to a rise in temperatures, particularly above 0 degrees Celisus, per a report by Iberdola. The orange-tinted rivers and streams were spotted by helicopter surveys. Ecologist Jon O’Donnell, who works with the National Park Service’s Arctic Inventory and Monitoring Network, said in a statement to UC Davis, “The more we flew around, we started noticing more and more orange rivers and streams.” He further suggested that some sites looked like “milky orange juice.”
Needless to say, the phenomenon is a threat to wildlife and nature and may cause environmental degradation. Increased levels of metals including zinc, nickel, copper, iron, and cadmium, with some of the smaller streams exhibiting a pH of only 2.3 were found through chemical analysis. The low pH level is equivalent to lemon juice or vinegar, per the US Geological Survey. As a result of thawing, the minerals packed up in the frozen soil free-flow in rivers and are exposed to rain for the first time ever. This allows the metals to dissolve out from the mineral-storing rocks into the streams and smaller waterways eventually merging with larger rivers and water bodies.
Study co-author Brett Poulin, an environment toxicologist at the University of California, Davis, indicated that the rivers “have to be stained a lot to pick them up from space.” Some of the orange rivers were traced back to 2008 as well. The scientists estimated that the toxic water could affect the survival of spawning fish causing knock-on effects on U.S. fisheries. According to a National Geographic Education report, Earth’s permafrost, that is the frozen layer of the planet, has warmed by 6 degrees Celsius during the 20th century, and predictions reveal widespread thawing is to occur by 2100.
Increased melting permafrost can add to the risk of already rising sea levels across Earth’s water bodies and facilitate erosion as the soil and sediment are washed away with the melting ice. Siberia, Canada, and the U.S. state of Alaska are some of the inhabited regions with vast swaths of permafrost, per the report. In the coming future, the situation is likely to worsen if the current pace of greenhouse gas emissions and unchecked global warming continues. Researchers have yet been unable to determine the full extent of the natural calamity and plan to conduct follow-up tests.
2023 was recorded as one of the hottest years on record. Thus, with such occurrences, researchers anticipate the metal contamination from melting permafrost to intensify causing a “positive feedback loop,” per the study. Fresh metals from newly thawed permafrost will easily flow in with the already acidic water, and the increased melting of frozen earth will give way to new rivers allowing the flow of rusty acidic waters. We had acid rain, now we may witness acid rives, thanks to humankind.