Arctic Rust

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By: Alex Lee

After seeing the cherry red stain on the slip of pH paper I held between my tingling fingers,  no one else in my group of scientists and adventurers volunteered to touch the water at our feet. I was straddling a small trickle bubbling out of the tundra and disappearing again into cracked earth in Alaska’s western Brooks Range. 

Alaska’s Arctic generally evokes images of gin-clear streams cutting through untrammeled valleys marked mostly by caribou hooves and wolf paws. Instead, black-stained dead tundra rolled down the hillside where orange water flowed between dead alders and willows. 550 miles northwest of home in Anchorage and perhaps 300 miles from Alaska’s road system, this corner of the northwestern Arctic is remote, even by Alaska standards. 

We were here to study waters like the acid spring at my feet and how climate change is reshaping the Arctic. This is our story: 

Rusting Rivers

For me, things began in 2009. I stopped along a creek high in the Brooks Range, puzzled as clear cold water turned iron red. I was 8 days from the road on my first trip to Alaska and the river was bleeding, 14 years later I know why — climate change. 

Patrick Sullivan and Roman Dial choosing a location to sample incoming acid rock drainage in the Alaskan Arctic.

The rusting river I encountered was in the Koyukuk drainage in Gates of the Arctic National Park. It was just one of many rivers and streams that have turned red in the past decade and a half. This began slowly in small creeks, indistinguishable from naturally occurring background levels of acid rock drainage—a process of iron and sulfuric acid leaching into water and oxidizing red. But while iron-rich water does naturally occur, rust has shown up in arctic rivers at a rate and scale unprecedented in modern times. 

Satellite imagery shows that since 2008 rust has flushed through river systems never before affected across the Brooks Range. This building change impacts water quality, invertebrate abundance (bugs), fish, wildlife, and people reliant on affected river ecosystems. 

Acid Trip

One reason such large-scale degradation went mostly unmonitored for so long is that it is unfolding in such a remote and difficult place to study. Aside from being a long way to travel, the mountains of the Brooks Range are a complex and difficult terrain to work in. For much of the year, an arctic winter grips the landscape in cold, dark, and snow. Only one road cuts through the range in the 600 miles from the Canadian border to the Bering Sea. Tight valleys make even bushplane landings hard to come by. The expense, range, and impact of helicopters makes detailed work difficult by a rotor. This leaves traveling by foot and boat the best way to both access and study the land. Ankle-biting tussocks, walls of alder, steep rocky mountainsides, grizzly bears, swift water, maddening densities of mosquitoes, and a complete lack of any maintained trails all further complicate the matter. 

 Our team looking for camp high in the Western Brooks Range.

Such a landscape requires any images of scientists holed up in labs, standing over beakers and chalkboards of equations be jettisoned. I joined a team led by legendary adventurer Roman Dial and Arctic ecologist Patrick Sullivan. Roman is a biologist and colleague at Alaska Pacific University who first noticed the unprecedented rusting, like me, by chance. After decades of northern exploration, he recognized this was something new. Paddy, a research professor at the University of Alaska, Anchorage, noticed the same from his many years of fieldwork in the northwest Arctic. 

Our work this season was the first extensive on-the-ground scientific look at Alaska’s rusting river phenomena along a full river system, from headwaters to mouth at a mainstream waterway. We transected an affected river system in the Kobuk Valley, taking water samples along the way to measure acidity, metal content, turbidity, and other impacts of rusting water. Roman also returned later in the summer with a team of geologists to further sample and understand the source and extent of the acid rock drainage. 

Acid rock drainage occurs when metal-rich sulfide minerals interact with water and oxygen. A bit like dropping a lemon wedge into a glass of water making the glass taste sour, rocks heavy with sulfide minerals make groundwater acidic. This happens naturally at a slow background rate, but if you have ever seen orange and red water near historic mine sites, you are seeing this process speed up by human activity. Cutting into bedrock means that new space is created for groundwater to move into the rock and out to the surface. This is akin to cutting up that slice of lemon in your glass — it becomes more sour. The chemical reaction that produces acid rock drainage also leeches heavy metal into the water. This is most commonly iron, aluminum, and manganese, but arsenic, lead, and many toxic metals also occur. Like sugar in a glass of lemonade, some of these metals are dissolved into the water, while others precipitate out and form crystals in the water.  

Acidic orange water burning the arctic tundra black.

It turns out climate change can also speed up this process on a massive landscape scale. Just like a mine cutting into the ground makes new space for chemistry, thawing permafrost means new interactions between water and rock. The frozen ground barrier between bedrock and surface water is melting, exposing rock to water and oxygen for the first time in many thousands of years. Permafrost was like the lemon peel and pith in our glass, no permafrost means all that pulp is now in the water, making it again more sour.  

The most affected sources we measured in the Brooks Range had water with a pH below 3 and a specific conductivity of nearly 7000. I spend much of the summer fishing and every fall I clean my tackle in a bowl of vinegar – our most extreme readings were about what you’d find if you measured that bowl after using it to clean my pile of rusty hooks.

Adventure Science

There were seven of us with a combined 150 years of remote wilderness experience out for two weeks in the field. We all knew the range, but Roman might know more hidden corners of the Brooks Range than anyone else alive. We quickly came to recognize the big seeps and tundra slumps, but he noticed the small changes too: vegetation along the riverbanks changing, caribou trails choked by tall willows, how newly wet or dry the tundra was, and innumerable subtleties on the land.

Packrafting into another effected stream for sampling.

Precise and indefatigable, Paddy managed to keep his shirt clean to the last day. He showed the scientist’s delight as measurements came in and the picture of what was happening came into focus. 

Forrest is another mountain legend and was one of my tent-mates on the expedition. He’s spent a lifetime under big skies from Antarctica to the Himalayas. I credit Forrest with keeping the bears away from us with a jovial and constant stream of stories or opinions. He carried a lion’s share and made miles fly by talking about consciousness, morality, cowboy coffee, and the future of civilization. 

Retired now, Ray was a forester for 30 years and an ultramarathoner. He knew wild lands like he’d been there before, even when he hadn’t. His skill set proved useful as we traversed 120 miles of wilderness while collecting data.

Maddy and Russel are both grad students. They energized the group, carrying unbridled enthusiasm as well as most of the scientific gear. Far from being greenhorns – the two twenty-five-year-olds have spent the past four summers walking some thousand miles of this northern terrain. 

Our team, from left to right: Roman, Russel, Paddy, Maddy, Ray, Alex, Forrest

It didn’t take long to find seeps of acid and metal bursting from tundra hillsides. The first week we spent sampling was by foot. Following ridgelines and bear trails, we collected water samples and took digital readings of source seeps and affected creeks. The second week we met a resupply plane, swapped out the filled water samples for pack rafts, and floated downstream to collect more. Roman was the conductor, taking notes and taking in the bird’s-eye-view. Paddy wielded our digital water quality meter. Ray filtered water for samples. Forrest prepared veils. I collected sediment. Maddy and Russel counted bugs. Our samples will help show the extent and severity of rusting. Once my initial task was complete, I pulled out a fly and a bit of fishing line. 

I helped Maddy and Russel count bugs too, we never found any in the rust. I never caught fish in the affected streams either.

As we walked and paddled, we looked at the land, the rivers, and the rocks and hypothesized about how things were shifting beneath our feet. Melting cut banks smelled like peated whiskey. An eerie lack of animals made the banks of this wild river feel quiet. We talked about climate, politics, nature, and the philosophy of science. We tried to make sense of the immensity on the horizon.

We still don’t know just how fast the rust is spreading, how long it might persist (thousands of years), or what this means for the ecosystem. We do know from places like historic mining districts that as the metal precipitate builds up layers on river rocks and as the pH drops, bugs run out of habitat, and their population declines. No more bugs means no more fish. The fish feed the bears, the bears fertilize the tundra, and the tundra feeds the caribou. As John Muir observed, “When we try to pick out anything by itself, we find it hitched to everything else…”

We ended our trip in the Inupiaq village of Kiana on the Kobuk River. White people didn’t make it to the area until 1900. No roads leave town. Milk cost $17 a gallon at the only store to have it in stock when we passed through. The community there, along with their neighbors along the Kobuk, relies on the fish and the caribou. The immense landscape upstream is so far from the fast food chains, the noise, and the conurbation of so much of the world today, but it is still not free from the heavy hand of human influence on the planet. The more we know about how the landscape is changing, the more we will know about how change might impact people and communities on the front line. 

Since that first trip in 2009, I have fallen in love with the Brooks Range. The mountains are the ancient tail of the Rockies. The north slope of the Brooks reaches out to a vast coastal plain along the Arctic Ocean at the edge of the world, and the large rivers draining south pour life into the boreal heart of Alaska’s interior. In recent years, a few routes have become more traveled, but it is still uncommon to see a human footprint over even great distances in the Range. Most peaks feel wonderfully random. Char and arctic grayling roll in nameless ripples. It feels like you could very well run into a mastodon, wooly rhino, or dinosaur at any turn. You would even be forgiven for harboring a suspicion that a unicorn is only ever one ridgeline away, and if you saw one, you would not be surprised. 

Empty caribou trails in Kobuk Valley National Park.

This summer we saw no bears, no moose, no caribou. We did see four Dahl sheep ewes, a species in sharp decline due to changing winter conditions. Through just my small window into this landscape, I see change. It feels brushier than it used to be. Change at the fringes always happens the fastest. 

I am still left with hope for the Arctic because of its sheer size. So much of the land remains intact that there is a great reservoir of resilience against the creep of change. However, there is no water treatment feasible to reverse the current trend. Continued monitoring can help us understand how durable these systems are in the face of global warming and what pieces might be most vulnerable. 

We can’t tackle the climate crisis without understanding the impacts of climate change just like you can’t pay a bill before seeing the check. Even in the National Parks and Wild and Scenic Rivers in the Arctic—set aside as special places—climate change arrived without outside recognition or resistance. 

Heat waves, glacial recession, and species loss make for well-known headlines, but climate change continues to unfold in quiet, novel, and unexpected ways too – understanding these impacts can help us adapt to changes, but also serves as a stark warning of global warming’s far reach. 

Waiting for our flight home it began to rain. Others in the group took refuge in the village office and talked with the locals about the restaurant that used to be in the same building and about this year’s late fish run. I stayed at the airstrip and took a nap in an excavator bucket. I dreamt of those unicorns, and couldn’t help but worry about their future.


Check out more photos and a podcast episode about Alex’s trip here.


Alex Lee

Author: Alex Lee

Alex Lee is a writer, skier, climber, gardener, wanderer of wild places, fisherman, dog walker, and environmental philosopher. Alex studies moral obligations and environmental problem solving as Associate Professor of Philosophy at the Institute of Culture and Environment at Alaska Pacific University in Anchorage, Alaska. He earned his Ph.D. in environmental ethics from the University […]