The effects of climate change can be seen through many different lenses. Specific to this discourse, the focus is placed on the effects that glacial retreat has on downstream water systems in the eastern Alaska Range. The entire continuum of this system–from glacier to river to the ocean–is affected by this change. It is a direct testament to the interconnectedness of this region, and the events and changes witnessed within this area can be extrapolated to glaciated regions around the world.

Glacier-fed water systems are highly important, in particular to regions where glacial runoff is integral to human activities such as farming, energy production, water supply, and subsistence lifestyles. Himalayan glaciers alone provide water for nearly 1.4 billion people. In Alaska’s interior, the river systems are integral to the subsistence lifestyle of Natives.

Specific to Alaska’s water systems, a combination of scientific data and real-world signifiers are viewed to showcase the current and future vulnerability of downstream systems to climate change and its effect on fishing, wild game, water supply and quality, and ultimately, the subsistence lifestyle of the people who inhabit these places. Concepts including water temperature variability and turbidity are directly influenced by glacial meltwater and its attributes. Changes in these variables dictate downstream impacts. With climate change–the most being significant global warming–these effects are often negative.

Changes in Water System Temperature and Sediment Load

In the long term, a reduction in glacial runoff will increase summer water temperatures downstream in various ways. One reason for increased summer water temperatures is due to an increase in atmospheric energy receipt with warmer air temperature (i.e. warmer air temperatures will create warmer water temperatures). A variable to this effect could be reduced radiation due to increased cloudiness. Another way in which water temperatures will rise is because of an overall decrease in the relative contribution of cold water from glacial melt. If less cold water is entering the system the overall temperature of that system will increase. A final reason for water temperature increase is due to the reduced heat capacity of rivers with lower flow.

Simultaneously, bedload and suspended sediment load are expected to decrease as runoff dwindles and erosion occurs at a lesser rate. This decrease in turbidity (i.e. the amount of sediment suspended within the water) will increase light penetration (i.e. more direct sunlight) to the bed of rivers and streams and will directly impact primary production and photo-chemical transformations of organic matter. Glacier retreat may also open new areas of unconsolidated glacial sediments and destabilize vulnerable slopes. This could create the potential for hazardous landslides and short-term increases in sediment yield from glacial basins.

Effects on Fish and Wild Game

Throughout time ecological communities have adapted to the environments created by the conditions of glacier-fed streams and rivers. Changes–big or small–in the overall water system will alter the physical and chemical balance of the environment these communities have adapted to. Ultimately, this will lead to a loss of biodiversity, ranging from algae to fish.

Salmon Population

Both Atlantic and Pacific salmon and trout species are a source of food for millions of people worldwide. Rising water temperatures have been linked to increased mortality of juvenile Chinook salmon, which have raised concerns of the future viability of this species. Population models indicate a 17% probability of a catastrophic loss in this fish species by 2100.

On the other end of the spectrum, in areas with intermediate to high glacial cover (i.e. eastern Alaska Range) increased glacial melt can have a cooling effect on mean stream temperatures during the summer months. This cooling effect can potentially reduce fish growth.

River Fisheries

River fisheries provide important sources of food in many regions. Changes in glacier-fed river fisheries due to variability in flow rate can create major local and regional economic problems.

For example, in the glacial Kenai River in Alaska, sport and commercial fisheries generate as much as USD $70 million to the state’s economy, but increased flow variability and flooding caused by enhanced glacier melting and glacial outburst floods can significantly affect these important fisheries. Associated large-scale changes in basin geometry and rerouting of meltwater may significantly affect salmon habitats.

Along the Pacific Northwest coast in North America, the creation of new salmon habitats has been shown to potentially benefit fisheries, and in a sense, slightly curb glacier-based problems.

Glacier-occupied land will significantly decrease by the end of the current century. Studies now show that not only does the melting of glaciers directly affect sea levels, but that it also affects downstream river ecosystems, and that these effects have negative societal implications. Changes in flow rate and sedimentary carry load are leading effects of climate warming, but global warming promises a web of interconnected problems to greater water systems and their users. It is obvious that this is a complex, non-black and white issue with many layers of interaction. In general, these changes have negatively impacted the land, wildlife, and people that engage with and make up this greater ecosystem. Undoubtedly, urgent attention and change are needed to curb these issues, both in the short term and for generations to come. Without immediate action, we stand to lose many of the beautiful and necessary parts of this planet that so many of us rely on every day.

Are All Outcomes Bad?

It’s a legitimate question and one that is difficult to answer. Climate change impacts our environment in numerous ways. Oftentimes these changes are negligible on the surface, but over time they compound into more radical and widespread problems. Much of what we are witnessing today is a negative change. We must take these negative changes at face value, but we also need to understand that the media plays a crucial role in building the overall narrative. The majority of the impact felt from climate change is negative, but there are some effects that help or at least may help water ecosystems and wildlife. These aren’t the changes that sell newspapers, but they are important to acknowledge nonetheless. And, in a field of study that is often dispirited by what we see, any positive outcome needs to be looked at with gratitude and as a beacon of hope.

Take What You Can Get

Future reductions in glacial runoff could actually improve the thermal sustainability of glacier-dominated rivers for salmon. Many un-previously seen salmon habitats have been created because of the glacial recession in Alaska. Due to this, over 500 new water systems–and salmon habitats–along the southeast coast of the state have been uncovered.

Glacier-fed rivers spend a larger proportion of their annual budget flow during the late summer and into the fall and winter than snowmelt-fed systems. This increase in summer flow can help facilitate the migration of anadromous salmon through water systems to spawning grounds at times when other sources of flow are low. Large runs of anadromous salmon in southcentral Alaska that support commercial, subsistence, and sport fishing occur in glacially influenced rivers. However, glacial shrinkage will decrease summer discharge, potentially restricting adult salmon spawners from migrating upstream.

Additionally, a slower flow rate throughout the summer months will have a negative impact on juvenile-rearing salmon. Sockeye salmon are shown to prefer turbid glacial meltwater for spawning, and turbidity can provide cover for rearing fish from predators. With that said, potentially higher flows in winter and early spring may help reduce mortality, in particular for overwintering salmon species.

Due to thawing permafrost (a mostly negative side-effect of climate change), many previously healthy lakes are becoming dry beds of dirt, rock, and leftover sediment. In return, areas around these lakes that were flat and without much vegetation are now promoting new plant and tree growth. This is a positive for larger game like moose that feed off vegetation such as willows or alders.

Beyond Science and Politics

A Conversation With Ray DeWilde

Climate-based sciences and political discourse are both inherently important when viewing and trying to combat the climate crisis. However, no technical chart, algorithm, or change in policy has a direct impact on repairing what has been lost. At least, not in the short term.

Ray DeWilde, an Athabascan Native originally from the village of Huslia, Alaska, bears this sentiment. DeWilde grew up on the Koyukuk River, a tributary of the Tanana River, and ultimately of Alaska’s largest river, the Yukon. He was raised on a subsistence lifestyle, fishing, trapping, and hunting for meals, and using the rivers for travel and as a source of freshwater. This was and is the way of life for many Native Alaskans that live in the state’s interior. Now, this way of life is changing dramatically. When first discussing the effects of climate change with DeWilde he put the situation in simple terms saying, “In my lifetime, the fish I used to catch and eat are not there anymore. The beavers I used to trap are no longer there. The way our people travel is changing greatly. It rains in December now. All of these issues are ongoing. Things aren’t going to change back anytime soon.”

The people of Huslia have witnessed significant changes to the environment throughout the last few decades, and continually see changes as each day passes. For instance, rivers now freeze later in the year and break up earlier the following spring. According to DeWilde, these rivers act like highways for people to travel on. “You can imagine what this means when you are living far away from the next village. There are no roads, and for much of the year, you move around by snow machine. We depend on stable snow and ice conditions for this.” In general, travel has become more difficult. However, some places that weren’t previously accessible by boat or canoe have opened to travel.

For subsistence lifestyles, traveling, fishing, and hunting all go hand-in-hand. Beyond travel becoming more difficult, the fish and wild game populations are decreasing dramatically within the area. Salmon populations are decreasing due to changes to the river systems and moose, beaver, and geese populations throughout the area are dwindling.

Specific problems within the area include high precipitation in the mountains, varying water turbidity levels, and heat stress to the rivers and streams. Turbidity levels have varying effects on the salmon populations (and other fish within the water systems). On a more direct, local level, DeWilde highlights the effect of high precipitation in the mountains on creating more river turbidity. This impacts the salmon population by drawing on spawning problems. Within the past 12 - 18 months DeWilde and his family members have noticed that salmon are now dying with eggs still inside of their stomachs. Generally, salmon will die off after laying their eggs. This hasn’t been seen before and is a disturbing sight for many of the locals.

Due to thawing permafrost, water levels are dropping in the summer, but flooding occurs in the fall. The majority of the effects of thawing permafrost are negative, but additional flooding does create more grassland areas which is a positive for hunters of large wild game. Playing into the negatives, a large downside to the alleviation of lakes and streams is the dwindling beaver population. This is one of the hardest-hit animal populations within Alaska.

The river systems and wildlife that rely on them are also being affected by action that isn’t climate-related, DeWilde notes. “The Yukon River and its tributaries are currently closed to fishing to help further sustain a dying-off salmon population. These shutdowns aren’t just a matter of climate change, but also of problems that stem from International Bycatch that is being done on the Pacific [Ocean]. These shutdowns have been occurring for nearly a decade now. This is a major issue for the subsistence lifestyle of the Native Alaskans that live along these riverways. They rely heavily on fish for food.”

Another wildlife population that is being greatly affected is geese. A warming climate paired with more erratic storm cycles on the U.S. mainland means fewer geese are stopping in Alaska’s interior. According to DeWilde, geese normally spend nearly two weeks in and around Huslia and the surrounding villages and basins. Now that the interior and north slope open up at the same time (i.e. the temperatures begin to warm at similar times and rates) geese bypass the interior and fly north without stopping. In the past, thousands and thousands of geese would stop in the interior. At times, their synchronous takeoff would darken the sky for dozens of minutes at a time. Now, Natives are lucky to see flocks in the hundreds.

This negative change in available wildlife for hunting and fishing is leading to a larger issue of food security. “You’ll hear Natives talking a lot about food security”, DeWilde said. “Alaska Natives are not part of the normal Western Culture. It’s not modern-American to hunt moose or beaver, or to pluck geese.” With this, the food source for Natives is changing for the worse. A good food supply [consisting of natural wildlife] is something inherent to the Native way of living. These new sources now include unhealthy options such as hot pockets, pizza rolls, soda pop, and other high-sugar foods. Processed foods are much cheaper to buy and easier to import into villages than fresh foods. DeWilde states that Western food is not an original part of their culture, and therefore is debilitating to their system. He’s noticing a lot of obesity, diabetes, and other health-related problems that he believes have a direct tie to their new diet.

At the end of the day, DeWilde draws the analogy that the current state of Alaska’s wildlife and greater ecosystems is similar to that of a new car. “The arctic is still very hostile and very pristine. Every new issue that comes about is very noticeable. It’s similar to driving a new car. If you get a scratch on a new car, you notice it right away. It’s the same up here. If there’s a change in our environment, however subtle, we’re going to notice immediately. It’s not like driving a car that’s been around the block a few hundred times. We haven’t got there yet, and I hope that we stop before we do.”