Warming Rivers Are Causing Die-Offs Among Alaska Salmon

Dead chum salmon lined snow-fed and rain-fed rivers across Alaska, where lethally high temperatures and low water levels prevented migration. With their original habitat under threat by global warming, cold glacial water is becoming more necessary for the survival of salmon.

Salmon are born in freshwater rivers. They swim to the ocean to spend their adulthoods, and then return to the rivers to spawn four or five years later, Holly Carroll, a Yukon-focused biologist at Alaska’s Department of Fish and Game, told GlacierHub.

Salmon felt the effects of July’s record-breaking temperatures in Alaska this summer as they struggled to reach their spawning grounds. They do not eat once they begin the journey back to the rivers, Carroll said, meaning that they have a limited amount of energy to make the trip. “So if they then encounter really warm water, it puts their body under much more stress,” she said. The heat speeds up their metabolisms so that salmon can run out of energy and die mid-journey.

As salmon suffer in Alaska’s warming snow- and rain-fed rivers, some scientists are looking to glaciers to predict the future of these fish. 

The Die-Offs

According to NPR, the largest die-off occurred in the Koyukuk River, a tributary of the Yukon River. The dead salmon count was in the thousands to ten thousands, Stephanie Quinn-Davidson, director of the Yukon River Inter-Tribal Fish Commission, told GlacierHub. She put together a team of scientists and surveyed 200 miles of the river to count the salmon—they found at least 850 dead —and confirm, by cutting the fish open, that they had not spawned and had no signs of disease.

“The die-off coincided with record-breaking temperatures in Alaska,” she wrote in a Facebook post.  Some places on the Koyukuk reached 90 degrees Fahrenheit from July 7 to July 11—25 degrees above average. July 12, she noted, was when when locals began seeing dead chum salmon floating downriver.

Quinn-Davidson’s team examines salmon along the Koyukuk River. (Source: Stephanie Quinn-Davidson)

The Koyukuk is fed by snow and rain, Carroll told GlacierHub. This year, the snow melted quicker, leaving the river with record-high water levels earlier in the season and very low levels in the summer. The drought also deprived the river of much-needed rainwater.

The Bristol Bay area also experienced salmon die-offs, particularly in the Igushik River, which flows from Amanka Lake into Bristol Bay. Tens of thousands of fish were found dead in the Igushik, according to Timothy Sands, area management biologist of the Nushagak/Togiak region.

An early-melting snowpack led to low water levels, aiding in the rise of temperatures, Sands told GlacierHub. The snowpack usually continues to melt through June, he said, but this year it vanished in May. Lower water levels enhanced the heating of these waters which are already susceptible to warming as a muddy river in the tundra.

While Koyukuk salmon died of heat stress, the Igushik salmon died of oxygen depletion, Sands said. The river is prone to oxygen depletion due to its geography: The elevation drop in the river is minimal, and so the flow of the river is slow and tidal. This means less recycling of water and less replenishment of oxygen.

High temperatures increase a salmon’s metabolism, so that it increases its need for oxygen at a time when there is less of it in the water, Mary Catherine Martin, communications director for Salmon State, told GlacierHub.

Even with the die-off, Sands said, the river reached its escapement goal, which is the number of fish that are required to reach their  spawning grounds in order to ensure a new generation of fish. “It’s a healthy system,” he said, noting that this year’s run was the third highest since 1884. 

Dead chum salmon lined the Koyukuk River this July. (Source: Stephanie Quinn-Davidson)

Habitat in Danger

Sue Mauger, science director at Cook InletKeeper, has been monitoring stream temperatures in Alaska’s Cook Inlet since 2002. She told GlacierHub that she was surprised there weren’t more salmon die-offs this summer, considering that the waters reached temperatures that are considered lethal for salmon. In the Deshka River, she said, temperatures were warmer than those expected for 2069 under a worst-case climate model.

The fish survive by finding cold-water refugia, which are pockets of cold water in which the salmon can wait for temperatures to diminish. In the case of the Deshka, she said, a connected glacial area provided this space for salmon to wait out the heat.

In deep rivers, groundwater inflows, side channels and springs provide the same service. But when rivers experience low water levels, “you don’t have those deep cold refuges, then the salmon don’t have anywhere to hang out and wait until the temperatures start to drop,” Quinn-Davidson told GlacierHub.

Development also harms this habitat, Mauger told GlacierHub. Abstaining from building near rivers is “a decision that we need to make,” she said.

In Bristol Bay, the Environmental Protection Agency took a step towards the opposite decision this month by allowing a mining project to progress unopposed, despite the risks to salmon.

A New Glacial Habitat

“This summer has a lot of the components that we should expect to see in the future, and that includes having a warm spring, which means that however much snowpack we have is going to melt out earlier,” Mauger said.

Salmon are finding new spawning grounds in the vast habitat of cool streams that Alaska’s receding glaciers are leaving behind. In Glacier Bay, Kenai Fjords National Park, and other areas, salmon are beginning to inhabit these streams that benefit from ice melt all summer long.

But the situation is more complicated, according to Chris Sergeant, a researcher at the University of Alaska, Fairbanks who studies the effects of temperature and other stream conditions on salmon. “While a glacial river might protect salmon from warm water temperatures [in the summer], they may not necessarily be the best place for salmon to grow in rear during all the other months,” he said. In the winter, he told GlacierHub, young salmon grow faster in warmer waters. Since glacial streams are prone to flooding, spawning there also means a risk that the eggs will be swept away in water.

In the summer, he said, “some of these fish will live in the glacial systems for a few months, and then they’ll move into a smaller tributary fed by rain or snow” for the remainder of the year.

These are juvenile fish, though. After salmon spend their adulthoods in the ocean, they return to the exact rivers they were born in to spawn the next generation, for better or worse. “A lot of studies recently suggest that not only do they return to the same river where they were born, but they also spawn… within twenty feet of where they were born,” Martin said.

Glacial mainstem rivers (the brown water) mix with other habitats in the Taku River watershed, located between Alaska and British Columbia. Preserving a diversity of habitats will help ensure healthy salmon populations continue in the face of climate change, Sergeant told GlacierHub. (Source: Chris Sergeant for the University of Alaska Fairbanks and the University of Montana)

Response to This Year’s Die-Offs

There is not much to be done about the die-offs besides collecting data, Carroll said. The locals—many of whom are native Alaskans—are key to this. With extensive tributaries, the Dept. of Fish and Game relies on locals to report natural events in the river.

In the case of the Koyukuk river, Quinn-Davidson said, the expedition she organized would not have happened without the Yukon River Inter-Tribal Fish Commission, which represents over thirty federally recognized tribes along the Yukon River. “Alaska is currently experiencing a pretty major budget crisis,” she said. “It was good that our organization could step in, bring us all together, provide the funding to take us all out there, and more properly document what was going on.”

Salmon are of great importance to the local communities, who rely on the fish for food and their livelihoods. A commercial fishery for chum salmon is located on the lower part of the Koyukuk. “That fishery really helps the local economy because most people that live along the Yukon are native Alaskans and there’s not a lot of local jobs,” she said.

“People were able to meet their needs for salmon this year despite the die-offs,” Quinn-Davidson said. “Now the big question is, how much will this die-off impact future years of salmon returning—because those salmon didn’t end up spawning.”

According to Carroll, it’s likely that the next generation will not be negatively affected, since fewer young salmon can minimize  over-competition.

The die-offs did not pose an existential threat to salmon this year. According to Martin, the multitudes of dead salmon, along with the state’s wildfires, were a reminder that “climate change is happening, and it’s real, and it’s going to be an increasing part of the conversation here in Alaska.”

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Roundup: Subglacial Drainage, Extremophiles and Yellowstone Name Change

Subglacial Drainage Under a Valley Glacier in the Yukon

From The Cryosphere: “The subglacial drainage system is one of the main controls on basal sliding, but remains only partially understood. Here we use an 8-year dataset of borehole observations on a small, alpine polythermal valley glacier in the Yukon Territory to assess qualitatively how well the established understanding of drainage physics explains the observed temporal evolution and spatial configuration of the drainage system.”

Read more about the study here.

Kathleen Lake Yukon on GlacierHub
Kathleen Lake in Klaune National Park, Yukon (Source: Creative Commons).

 

Extremophiles at Deception Island Volcano in Antarctica

From Extremophiles: “Deception Island is notable for its pronounced temperature gradients over very short distances, reaching values up to 100 °C in the fumaroles, and subzero temperatures next to the glaciers. Our main goal in this study was to isolate thermophilic and psychrophilic bacteria from sediments associated with fumaroles and glaciers from two geothermal sites, and to evaluate their survivability to desiccation and UV-C radiation. Our results revealed that culturable thermophiles and psychrophiles were recovered among the extreme temperature gradient in Deception volcano, which indicates that these extremophiles remain alive even when the conditions do not comprise their growth range.”

Learn more about extremophiles here.

Image of an extremophile, Tardigrades, which are found in a range of extreme environments (Source: E. Schokraie et al./Creative Commons).

 

Native Americans Seek to Rename Yellowstone Peak

From The Guardian: “A valley in Yellowstone National Park in Wyoming, formed by a glacier, may get a new name. Hayden Valley is glacial, dating back to the last Ice Age. It was named after a surveyor, Dr. Ferdinand V. Hayden who advocated removing Native Americans from the region. The Great Plains Tribal Chairman’s Association, comprising tribal chairmen of 16 Sioux tribes from Nebraska and the Dakotas, is pursuing an application to change the name of Hayden Valley to Buffalo Nations Valley.”

Find out more about the news here.

Hayden Valley Yellowstone on GlacierHub
Hayden Valley (Source: Yellowstone National Park).

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Roundup: New Bacteria, Poetic Shasta, and Glacial Melt

New Bacteria Discovered at Tibetan Glacier

From Microbiology Society: “A cold-tolerant, translucent, yellow-pigmented, Gram-stain-positive, non-motile, rod-shaped bacteria was isolated from snow of the Zadang Glacier on the Tibetan Plateau, PR China. 16S rRNA gene sequence similarity analysis indicated that the isolate was closely related to Conyzicola lurida KCTC 29231 and Leifsonia psychrotolerans DSM 22824 at a level of 97.72 and 97.49 %, respectively. Other close relatives had a 16S rRNA gene sequence similarity of less than 97 %… Based on phenotypic and chemotaxonomic characteristics, strain ZD5-4 was considered to represent a novel species of the genus Conyzicola, for which the name Conyzicola nivalis sp. nov. is proposed.”

Read more about the new species of bacteria here.

An aerial image of the Tibetan Plateau where a new species of bacteria was discovered (Source: NASA/Creative Commons).
 

U.S. Geologist Clarence King’s Poetic Mount Shasta

From Project MUSE: “But, for all his complexities, King’s recorded observations of wilderness places rise above his life’s convolutions. Unfortunately, what escapes many scholars is the remarkableness of King’s writing, an irony considering its salience; in fact, King’s brilliance is best illustrated in his lexical finesse, poetic flights of language, and artistic verisimilitude of nature’s beauties.”

Learn more about the poetic perceptions and mastery of language of the late geologist Clarence King here.

Sunrise over Mount Shasta (Source: Michael Zanger/Creative Commons).
 

New Insights on Glacier Meltwater

From Geophysical Research Letters: “Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2), a subbasin of the Tanana and Yukon Rivers, show glacier meltwater runoff as a large component (15–28%) of total annual streamflow despite low glacier cover (3%)… Our findings suggest a linkage between glacier wastage, aquifer recharge along the headwater stream corridor, and lowland winter discharge. Accordingly, glacierized headwater streambeds may serve as major aquifer recharge zones in semiarid climates and therefore contributing to year-round base flow of lowland rivers.”

Read more about the new research here.

The Tanana River, Alaska (Source: Ron Reiring/Creative Commons).

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Glacial Retreat Causes A Yukon River to Disappear

Much to the alarm of Canadians, the glacier-fed Slims River has disappeared following extensive glacial melting associated with anthropogenic climate change. Views of the Slims Valley, where the river once flowed, have been replaced by a dry plain, marked only by the sinuous bevels left behind by the river in the soil. These changes have major implications on local ecosystems and will inevitably result in lower water levels in downstream glacial lakes.

For example, for many years, the Yukon’s Kluane Lake has been fed by the continuous flow of the Slims River. Water in the Slims River had been transported from Kaskawulsh Glacier, feeding the Kluane Lake and flowing into the Bering Sea. The Kaskawulsh Glacier is a large temperate valley glacier that lies in the St. Elias Mountains. It measures more than four miles across at its widest, where it meets the Slims and Kaskawulsh Rivers. With the recent melting of the glacier, water has been diverted in the direction of the Kaskawulsh River, which drains nearly 500 kilometers away in the Gulf of Alaska.

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Map showing the re-routing of glacial meltwater. Previous route in green, current one in red (Source: Google Earth).

Jeff Bond of the Yukon Geological Survey stated to Paul Tukker of CBC News, “Folks have noticed this spring that the [river has] essentially dried up.” This loss of streamflow is the first regional occurrence in the last 350 years, according to the Yukon Geological Survey. Some of the warmest temperatures on record in 2015 and 2016 have had major implications on glacial health in the region, with ice loss reported throughout the surrounding Saint Elias Mountains, as reported by the National Oceanic and Atmospheric Administration (NOAA).

The rangers in the Kluane National Park noted that the Kaskawulsh Glacier has retreated nearly a half mile to the point where its melt water is now traveling in a completely different direction. In this case, the diversion of glacial meltwater is so substantial that no water is flowing in the direction of the Slims Valley and the downstream Bering Sea. Despite the Slims normally flowing approximately 19 kilometers from the edge of the glacier to Kluane Lake through the Slims Valley, changes to the Kaskawulsh’s spatial distribution have caused meltwater to flow not westward but to the east, flowing into the Pacific Ocean.

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A view across the expansive alpine lake in Kluane National Park (Source: James Bunt).

The change in water patterns has major implications for ecosystems in regions experiencing new levels of flow (both in the dryer and the now wetter areas). For example, in the absence of perennial water, the Slims Valley is more prone to dust storms, at least until new vegetation stabilizes the floodplain. Retired Utah Geological Survey geomorphologist Will Stokes told GlacierHub, “The valley may undergo a major ecological evolution over the next few decades, characterized by new flora and fauna.” Although this may seem like a minor adjustment, Stokes explained, “These changes can drastically alter the local food chain, and if lake levels end up lowering dramatically, there may be a major negative impact on local hunting and fishing.”

Jeff Bond further speculated to CBC News that the melt-water system which fed the Slims Valley may have only been a temporary outflow from the Kaskawulsh Glacier, representing a “300-year blip” on a much longer geological timescale in which large glaciers evolve. A study by Harold Borns in the American Journal of Science supports the notion that water began flowing northward around the year 1700, when climatological events caused the glacier to advance, ultimately diverting a large portion of snowmelt towards the Slims Valley and creating the Kluane Lake. This relationship illustrates the impact that regional climate has had on glacial events, with recent warming reversing the changes that occurred in a colder climate multiple centuries ago.

“Although it’s hard to tell how much lake levels in the Kluane will decrease, locals can expect an abrupt decrease in levels,” Stokes added, “followed by a much slower, long-term loss of water once levels stabilize.”

The Yukon Geological Survey postulates that water levels in Kluane Lake will lower by a meter or more in the foreseeable future. Although the Kluane National Park region is not densely populated by humans, lower water levels in the Kluane may stress trout and whitefish populations that are fished throughout the region’s warm months by both locals and visitors.

Although the diversion of water away from downstream communities may, in this case, be unsurprising to Yukon geologists in hindsight, it does shed light on the powerful effects of warmer temperatures and evolving climate dynamics on natural landscapes. The flow of rivers and plentiful caches of freshwater that exist in many regions due to glacial activity may be at serious risk as melting continues and water flow is redistributed.

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The Slims River West Trail running along the receding Kaskawulsh Glacier (Source: Dan Arnold).

It is difficult to tell how quickly changes like those that have occurred in the Yukon may happen in the future, yet these events may serve as a microcosm for the forthcoming state of glacial systems in light of anthropogenic climate change. Despite the ongoing study of glacial evolution by earth scientists, events like this in the Yukon really catch the attention of locals and illustrate first hand the effects of living in a warmer world.

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Roundup: GLOFs, Presidential Warnings, and Glacial Lakes

Obama: Climate Change ‘Could Mean No More Glaciers In Glacier National Park,’ Statue of Liberty

From Breitbart: 

“During Saturday’s Weekly Address, President Obama stated, “the threat of climate change means that protecting our public lands and waters is more important than ever. Rising temperatures could mean no more glaciers in Glacier National Park. No more Joshua Trees in Joshua Tree National Park. Rising seas could destroy vital ecosystems in the Everglades, even threaten Ellis Island and the Statue of Liberty.”

To read the full transcript of the President’s Weekly Address, click here.

 

Melting Glaciers Pose Threat Beyond Water Scarcity: Floods

From VOA News: 

A melting block of ice from a Pastoruri glacier in Huaraz, Peru.
A melting block of ice from a Pastoruri glacier in Huaraz, Peru. Source: Associated Press.

The tropical glaciers of South America are dying from soot and rising temperatures, threatening water supplies to communities that have depended on them for centuries. But experts say that the slow process measured in inches of glacial retreat per year also can lead to a sudden, dramatic tragedy. The melting of glaciers like Peru’s Pastoruri has put cities like Huaraz, located downslope from the glacier about 35 miles (55 kilometers) away, at risk from what scientists call a ‘GLOF’ — Glacial Lake Outburst Flood.”

Click here to read more about the risk of glacial lake outburst floods from GlacierHub’s founder and editor, Ben Orlove.

 

Yukon has a new lake, thanks to a retreating glacier

From CBC News: 

Cultus Bay
Cultus Bay, now cut off from Kluane Lake by a gravel bar. Source: Murray Lundberg.

“Yukon has lost a river, and now gained a lake, thanks to the retreating Kaskawulsh glacier.

Geologists and hikers first noticed earlier this summer that the Slims River, which for centuries had delivered melt water from the glacier to Kluane Lake, had disappeared — the glacial run-off was now being sent in a different direction. Now, the level of Kluane Lake has dropped enough to turn the remote Cultus Bay, on the east side of the lake, into Cultus Lake. A narrow channel of water that once connected the bay to the larger lake is gone, exposing a wide gravel bar between the two.”

To read more, click here.

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Roundup: Changing Waterways, Hotter Parks, Glacier Music

As a Glacier Retreats a Major Water Source Dries Up

From CBC News:

Looking up the Slims River Valley, from the south end of Kluane Lake. The river used to flow down the valley from the Kaskawulsh glacier (Source: Sue Thomas/CBCNews)

“It’s [the Kaskawulsh glacier] been the main source of water into Yukon’s Kluane Lake for centuries, but now the Slims River has suddenly slimmed down — to nothing.

‘What folks have noticed this spring is that it’s essentially dried up,’ said Jeff Bond of the Yukon Geological Survey.

‘That’s the first time that’s happened, as far as we know, in the last 350 years.’

What’s happened is some basic glacier hydrology, Bond says — essentially, the Kaskawulsh Glacier has retreated to the point where its melt water is now going in a completely different direction, away from the Slims Valley.”

Check out he full story here.

 

Rising Temperatures in National Parks Like Glacier Bay

From Climate Central:

Temperature change in Glacier Bay National Preserve (Source: Climate Central)

“With such a wide variety of climates across the park system, the country’s 59 National Parks all have different challenges to manage in the changing climate. Some parks have experienced dramatic temperature changes, and these shifts can lead to water shortages (or too much water), ocean acidification, and species migration…. Glacier National Park — The number of glaciers has been cut in half since 1968, and the largest glaciers are expected to be gone within the next 15 years.”

Look at temperature trends in national parks here.

 

Hosted by Greenpeace: Professional Pianist Plays on Glacier

From Greenpeacespain on YouTube:

“Through his music, acclaimed Italian composer and pianist Ludovico Einaudi has added his voice to those of eight million people from across the world demanding protection for the Arctic. Einaudi performed one of his own compositions on a floating platform in the middle of the Ocean, against the backdrop of the Wahlenbergbreen glacier (in Svalbard, Norway).”

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