Experts Know What’s Causing Rivers To Turn Orange, But They Don’t Know Why

There are few places in the United States more protected than the Kobuk Valley National Park in Alaska, but that hasn’t stopped a stream that runs through the area from picking up what looks like a troubling amount of pollutants.

“This is bad stuff”

That was the response from University of Alaska Anchorage ecologist Patrick Sullivan when he surveyed the remote area last year.

He took some measurements and found that the stream’s pH level was roughly 100 times higher than the river into which it deposited. He also determined that it contained so many dissolved minerals that it more closely resembled wastewater than the fresh mountain stream one might expect.

Sullivan offered some concise advice: “Don’t drink this water.”

A rusting river

The stream runs into the Salmon River just a short distance away from where Sullivan obtained his measurements, and it’s notable because of its inclusion in writer John McPhee’s 1975 book “Coming into the Country.”

He wrote that it boasted “the clearest, purest water” he’d ever seen.

Less than 50 years later, it’s teeming with oxidized iron, giving the water a rusting appearance. And the same thing has been documented in dozens of rivers and streams across the region.

Searching for solutions

Alaska’s remoteness and cold weather had kept it pristine for generations, but that appears to no longer be the case — and experts blame climate change.

Fish and other wildlife are disappearing and once permanently frozen areas are beginning to thaw. And while ecologists had a lot of hypotheses about the impact of climate change, rusty rivers generally weren’t among them.

Now they’re playing catch-up to not only understand the cause, but figure out a solution before it is too late for this environmental oasis and others like it around the globe.

Chris Agee January 27th, 2024

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