Climate & environment

The permafrost is thawing – heavy metals color the rivers fire yellow

Christina Nordh

Updated 2024-05-25 09.51 | Published 2024-05-24 15.16

 

It looks like orange paint spilled into the Kutuk River in Alaska, but it's melting permafrost and releasing toxic metals. Now the fishing industry and the sensitive ecosystems of the rivers are threatened. Photo: Ken Hill/National Park Service

The permafrost in Alaska is thawing.

Now the rivers are dyed fire yellow and they have become as sour as vinegar.

The polluted rivers are clearly visible from space - and the problem is expected to increase, according to a new study.

The once crystal clear rivers of Alaska are a thing of the past. In recent years, several dozen of them have changed color to orange, writes Live Science.

The problem is spelled out by high levels of toxic metals released into the water by melting permafrost. It is about high levels of zinc, nickel, copper, cadmium and iron.

The pH value is 2.3 – at a similar level to vinegar or lemon juice.

Now the US fishing industry is threatened, the low pH value causes serious problems for spawning fish and for the ecosystems.

Seen in pictures already in 2008

In the study, published May 20 in the journal Communications earth & environment, researchers identified at least 75 rivers and streams in Alaska's Brooks Range affected by the spills through helicopter mapping.

- The more we flew around, the more orange rivers and streams we saw. Some places almost look like milky orange juice, Jon O'Donnell, the study's lead author and an ecologist with the National Park Service's arctic inventory and monitoring network, said in a statement.

In 2018, the researchers discovered that a river in the area that had been crystal clear the year before had now turned rust colored. But. When satellite images were then studied, rust-colored rivers were found as early as 2008.

As the water acidifies, it becomes easier for more metals to dissolve from the newly thawed permafrost. That creates an exponentially bigger problem.

Creates serious problems

The melting permafrost could also create new rivers in Alaska and Siberia – making the situation even worse.

According to co-author Brett Poulin, these are heavy pollutants, otherwise they would not be visible from space.

Now the researchers are planning a follow-up study, but they are worried that the record-high temperatures of recent years have caused further releases of metal.

Loss of permafrost also leads to more emissions of greenhouse gases, to the exposure of radioactive materials and to the awakening of "sleeping" viruses that can trigger new pandemics.

Two brown bears hunting salmon in Katmai National Park and Preserve in Brooks Falls, Alaska. Photo: Mark Thiessen/AP