why is the water more and more orange?

An aerial view of the rust-colored Kutuk River in the Gates of Arctic National Park in Alaska. Thawing permafrost exposes minerals to erosion, increasing the acidity of water and releasing metals like iron, zinc and copper. Credit: Ken Hill – National Park Service.
Christian Garavaglia Christian Garavaglia Meteored Argentina 05/24/2024 12:00 7 mins

Dozens of Alaska’s most isolated streams and rivers are turning from crystal blue to murky orange, and it could be the result of minerals exposed by thawing permafrostaccording to new research published in the journal Nature Communications: Earth and Environment.

For the first time, a team of researchers from the National Park Service, the U.S. Geological Survey, the University of California at Davis and other institutions have documented and sampled some of the altered waters, identifying 75 locations in an area the size of Texasin the Brooks Range, northern Alaska.

These degraded rivers and streams could have significant consequences for drinking water and fisheries in Arctic basins as the climate changes, the researchers said.

“The more we flew, the more we noticed more and more orange rivers and streams,” said lead author Jon O’Donnell, an ecologist with the NPS Arctic Monitoring and Inventory Network. “There are some places that almost look like milky orange juice. These orange streams can be problematic because they are toxicbut they could also prevent fish from migrating to spawning grounds.”

Orange water in Alaska visible from space

O’Donnell first noticed the problem when he visited a river in 2018 that appeared rusty although she was clean the previous year. He began researching and collecting sites while taking water samples where possible in remote areas, where helicopters are usually the only way to access rivers and streams.

“Colored rivers are so big we can see them from space,” said Brett Poulin, an assistant professor of environmental toxicology at UC Davis, who was the principal investigator of the research. “You have to dye them a lot to be able to capture it from space.”

An aerial view of the Kutuk River in Alaska's Arctic Gateway National Park, which looks like orange paint flowing into clear blue water. Credit: Ken Hill – National Park Service.
An aerial view of the Kutuk River in Alaska’s Arctic Gateway National Park, which looks like orange paint flowing into clear blue water. Credit: Ken Hill – National Park Service.

Poulin, whose background is in water chemistry, thought the stains were similar to what occurs with acid mine drainage, except thatthere are no mines near deteriorated rivers, including along the famous Salmon River and other federally protected waters.

One hypothesis is that permafrost, which is essentially frozen ground, stores minerals and that as the climate warms, the once-captured metallic minerals have been exposed to water and oxygen, leading to the release of acid and metals.

“Chemistry tells us that minerals erode,” Poulin said. “Understanding what’s in the water is a fingerprint of what happened.”

Highly acidic and corrosive conditions

Some altered water samples have a pH of 2.3 compared to the average pH of 8 for these rivers. It means that sulfide minerals erode, creating highly acidic and corrosive conditions that release additional metals. High or high levels of iron, zinc, nickel, copper and cadmium have been measured.

“We see many different types of metals in these waters,” Evinger said. “One of the most dominant metals is iron. That’s what causes the color change.”

High or high levels of iron, zinc, nickel, copper and cadmium have been measured.

While O’Donnell first noticed a change in 2018, satellite images showed stained waters dating back to 2008.

Over time, the problem spreads slowly from small springs to larger rivers,” he said. “When problems or threats emerge, we need to be able to understand them.”

Understanding the risk

Researchers are in the second year of a three-year grant aimed at understanding what’s happening in the water, modeling other areas that could be at risk, and assessing the implications for drinking water and populations of fish.

The problem is growing and affecting habitat, water quality and other ecological systems, turning healthy areas into degraded habitats with fewer fish and invertebrates. If rural communities rely on these rivers for their drinking water, they could eventually need treatment and the fish populations that feed local residents could be affected.

NASA reveals critical map of fresh water reserves in Brazil and around the world! What does this map reveal?

NASA reveals critical map of fresh water reserves in Brazil and around the world! What does this map reveal?

“There are a lot of implications,” O’Donnell said. “As the climate continues to warm, we expect permafrost to continue to thaw. So wherever these types of minerals are found, waterways are likely to turn orange and deteriorate in terms of water quality.”

Further work is needed to better understand the problem and whether rivers and streams can recover.

News reference:

O’Donnell, JA, Carey, MP, Koch, JC et al. Mobilization of metals from thawing permafrost into aquatic ecosystems leads to rusting of Arctic waterways. Common Earth Environ 5, 268 (2024). https://doi.org/10.1038/s43247-024-01446-z

-

-

PREV Sales Of Russian Uranium Oil To India Are At All-time Low…
NEXT The Montpellier Cancer Institute trains children on the risks of sun exposure, responsible for 2,000 deaths per year