State of Alberta’s Trout: Cutthroat Trout PT. II

State of Alberta’s Trout: Cutthroat Trout PT. II

Current Threats and Management

In the last post, I introduced the Cutthroat Trout and talked about some of their ecology, along with hybridization with rainbow trout. If you missed it, check it out by clicking here.

In this post, I am going to get into the nitty gritty…. How did we end up here? What are the biggest threats facing this trout? What is being done to minimize them? How does this relate to conservation of this species moving forward? I am excited to bring you this post, as I think it touches on many land use issues that we have in our province in general. We will talk mining, forestry, angling, and talk about some of the ways the government plans to maintain cutthroat trout in the years to come. So lets get to it!

The debate isn’t about whether they should be saved but rather how to save them, and how quickly we need to act. Two essentials for these fish are place and space- cutthroats and their habitats are intertwined, interconnected and incapable of being separated.

– Lorne Fitch, Caring for Cutthroat (from Alberta Westslope Cutthroat Trout Recovery Plan 2012-2017)

Threats Facing Cutthroat Trout

The major source I will be citing throughout this post is the Alberta Westslope Cutthroat Trout Recovery Plan 2012-2017, (hereon referred to as Action Plan) from the Alberta government. This document, despite being a few years out of date, provides an extensive overview of the threats facing cutthroat trout and the governments plan of action for dealing with these threats. It was compiled using information and research from a variety of very qualified biologists in our province, many of whom have spent a good deal of their careers researching cutthroat trout. I will also reference the recovery strategy document from the Federal government (DFO 2019), David Mayhood’s Conceptual Framework and Recovery Guidelines for restoring Westslope Cutthroat Trout Populations in Alberta (Mayhood 2014), and several results from the Alberta Conservation Association, for whom I had the privilege of working for last summer. Links to all this material is available at the end of the post if you are interested in doing some extra reading.

So let’s get to it!

We know from the last post that hybridization with rainbow trout is one of the most important concepts for cutthroat trout conservation. But is this the cause of their demise, or just a symptom? As Lorne Fitch so eloquently said in the quote above, the essential thing for cutthroat is their HABITAT. They are inextricably linked to it, and while something like hybridization might seem unrelated to habitat, I will show you how they are actually closely related.

The recovery plan very succinctly summarizes the source of most of the threats facing cutthroat trout: HUMANS. They say our activities are the single biggest threat, and outline how our activities have caused irreversible damage to the species. Our effects come in the form of angling, water usage for agriculture and ranching, industrial activities like forestry and mining, road building, and the legacies of fish stocking. Legacies such as these cannot be easily undone, and unfortunately we will NEVER get our original fisheries back. But we can strive to conserve what we have left, and make positive steps towards recovery.

The threats facing cutthroat were summarized into six categories in the Action Plan. I have listed them below:

  • Invasive Species
  • Adverse effects on habitat
  • Exploitation
  • Stocking
  • Pollution
  • Climate Change

Invasive Species and Stocking

We have already discussed invasive species at great length, however, the threat of invasive species goes well beyond the introduction of non-native fish like rainbow trout. Invasive species also include invasive aquatic plants/algae, such as didymo (AKA rock snot), which greatly lower productivity and spawning opportunities. Whirling disease (WD) also falls into the category of invasive species; the agent that causes this deadly disease is an invasive parasite that uses a Tubifex worm and trout to complete its life cycle. For more on whirling disease, check out the Whirling Disease in Alberta page.

So as you can see, invasive species come in many forms, and impact cutthroat in different ways. But in general, invasive fish species increase competition for cutthroat and often drive them out of their habitat. Invasive plants impact habitat, reduce spawning potential, and impact invertebrate communities. Invasive pathogens like WD are most deadly for juveniles and significantly decrease survivorship of young fish. It is thought that areas containing pure westslope cutthroat do not provide great habitat for the Tubifex worm, and therefore the threat to cutthroat is somewhat less compared to fish species that occupy the lower reaches of streams.

Habitat, Pollution, and Climate Change

The remaining range of pure cutthroat trout in Alberta is subject to many industrial and recreational land uses. These areas are some of the most heavily logged in the province, and there is also natural gas activity, mining exploration, and heavy OHV use. All of these activities negatively effect cutthroat trout habitat.

Changes that impact the habitat of cutthroat trout are the most complex, the hardest to mitigate, and the most impactful. These issues are intricately linked with climate change and pollution, and thus I will discuss them together. There are two habitats in particular that are of crucial importance. Those are spawning habitats and overwintering habitats.

Cutthroat spawn in small tributary streams in the upper reaches of watersheds. Often these streams are no more than a few feet across. For example, take a look at the small stream that we captured pure cutthroat spawners from last year (for the brood stock collection program, more on this later in the post). This stream was only about two feet across. These streams are often considered fishless by forestry companies and logging activities often take place in near proximity to them; however conserving the hydrology of these streams is very important. These are the areas that have gravels of the right size for fish to successfully reproduce. Clear-cutting and the associated road building activities increase sediments in these habitats and limit their spawning potential. They also promote surface run-off, as apposed to soil infiltration. Essentially, water does not permeate the ground as well; this means the water levels peak earlier in the spring, and later in the season there is not enough water left in underground aquifers to recharge these streams, leaving them without water during the critical time when the fry are hatching.

A Cutthroat Trout Spawning Area. As you can see, these habitats are often little more than a trickle and very easy to overlook.

Once cutthroat fry emerge sometime in the late summer, they essentially have 2 months to grow as much as possible and set themselves up to survive the long winter ahead. This is a very important time for them, and the vast majority of fish that hatch will not make it through their first winter. What they require to survive is an overwintering pool- a deep area of the stream that will not completely freeze in winter. These fish will survive well in smaller streams where there are less predators (aka Bull trout), lots of deep pools, and significant groundwater inputs which prevent the creeks from freezing fully. In streams that have this mix, juvenile cutthroat densities will be very high. These are known as rearing habitats. Juveniles will live in these streams for many years, where they will grow before heading to larger rivers once they mature into adults. So it is essential that these rearing streams are maintained, as they provide the habitat required for juveniles to mature into the adult fish that we love to fly-fish for in the mainstems. In my opinion, they are the most critical habitat feature for cutthroat.

More Cutthroat Trout Spawning habitat in the Upper Oldman Watershed. These habitats are critically important for cutthroat trout.

That is where the effects of climate change come in. Research has indicated that climate change is leading to lower snowpacks, lower flows in late fall and winter, leading to more ice formation and less overwintering pools. This on it’s own poses a great threat. When that is coupled with rampant clear-cutting, these effects are further exacerbated- logging leads to earlier peak flows, lower flows later in the season, and less groundwater, on top of increased sediment. This double whammy has the potential to significantly alter these rearing streams, to the point where they may no longer be suitable for trout.

Climate change is also related to hybridization and habitat loss. We know that thermal gradients are responsible for the patterns of hybridization we see. This trend of warming stream temps is allowing hybrids to move further and further upstream. Changes to habitat can also lead to the same thing. For example, water licenses lower the flows of the river allowing it to warm faster, promoting upstream movement of hybrids. Any factor that could increase stream temperatures has the potential to exacerbate hybridization.


That leads us into our discussion about logging. Many people may not be aware that a single company, Spray Lakes Sawmills, has exclusive timber rights to the entire upper Oldman river watershed. Now without getting too political, lets just say I have some concerns with the way this area is being logged. Their long term harvest plan outlines their plan to log EVERY tributary in the upper Livingstone. Anyone who has fished in the area recently has been treated to views of vast clearcuts throughout the watershed- you can expect this to continue for the next 20 years at least. This is a major concern.

For example, the five year population monitoring study done by ACA has shown White Creek to contain the highest density of cutthroat every single year of the study. White creek is irrefutably some of the best rearing habitat in the watershed, and probably the most important stream for maintaining the cutthroat trout in the mainstem Livingstone. The watershed is due to be clearcut within the next five years. Other tributaries that will be logged include Ridge Creek, Deep Creek, and Beaver Creek. I don’t believe this harvest plan is sustainable, or in any way aligned with the goals of cutthroat trout recovery in the area. Granting exclusive harvest rights to a company that is not willing to do its part for conservation is a major red flag, and should be a concern for everyone. Below is the long-term harvest plan for Spray Lakes in the Livingstone area. The orange areas represent cutblocks that will be logged this year, where grey shows areas that have already been logged. Red lines represent roads that will be built. Notice the large cuttblocks in the upper reaches of White Creek (second figure), which flank the small tributaries that are important for both spawning and rearing.

Source: Spray Lake Sawmills (Link:

As you can see, there are significant areas due to be clearcut in the near future. To add major mining projects to the area would just add to the industrial footprint, as this would lead to more clear-cutting, road building, water usage, and would also mobilize toxic pollutants such as selenium. The area cannot withstand this added pressure. While we narrowly avoided these mines going into production, the legacy of the exploration that was done in one summer is painted in the landscape, as their were hundreds of kilometers of roads built with very little foresight. I expect the battle against mining in the area is far from finished, and we must remain vigilant in standing up against expanded industry in pure or mostly pure cutthroat habitats.


This is the threat we have the most control over as anglers. Earlier this year, I made a post that sparked conversation over the ethics of angling. One of the sentiments I heard repeated was that anglers may be selfish and inflicting harm on fish, but we are also the user group most invested in protecting and conserving these resources. Without us, there would be less awareness and pushback for issues that impact trout. I agree with this, and it must continue to be this way. We are the streams greatest protectors, and therefore we must do everything we can to do our part when angling.

Without a doubt, the areas of pure and mostly pure cutthroat trout are heavily over-angled. Out of probably 200 or more fish over 15″ that I handled last year, their were less than 10 fish that showed no hooking damage. Hooking damage is present on almost all large fish in these systems. In some reaches, my guess is that fish get caught near daily, and sometimes multiple times in the same day. Even with low C & R mortality estimates, this translates to significant losses from angling. And this damage is from fly-fishers- don’t go throwing shade at spin casters who use treble hooks. They are a vast minority in the area compared to fly-fisherman. That doesn’t mean I don’t agree with single barbless hook regulations being imposed in the area- I just don’t want to deflect from the impact of fly-fishing as the primary contributor to hooking damage, mostly from sheer volume of anglers and low population sizes. The figure below is the perfect representation of this. It’s from an angler effort survey conducted on the Oldman in 2018. You can see fly-fisherman outnumber gear fisherman by roughly 9:1.

Source: Hurkett, B., and K. Fitzsimmons. 2019. Angler survey in the Upper Oldman River watershed,
Data Report, produced by the Alberta Conservation Association, Sherwood Park,
Alberta, Canada. 17 pp + App.

One of the takeaways I had from electrofishing the mainstems of the Livingstone and Oldman last year was the surprisingly low densities of fish. As an angler, I always had the impression that for every fish I caught, there were dozens more in the pool that I didn’t catch. Last year, however, I got to electrofish reaches that I had fished extensively. In most cases, there are only 2-3 cutthroat in any given pool or run. I often caught as many angling as we did electrofishing. If conditions are right, a proficient angler might literally catch every single trout in a run, or in a stretch of river. Because they are catching so many, it leads to the impression that the fish are more plentiful than they are. The reality is that cutthroat are not that hard to catch, and they have a short window to feed each year so they must continue to risk being caught. They are vulnerable to angling. One angler who is not committed to safe C & R, or who is poaching, can have pretty significant impacts at the population level. This trend changes when you get into habitats that are devoid of bull trout. In these areas, the cutthroat tend to be very densely populated and much smaller.

Management Strategies

The discussion of the threats above should make clear the complexity of the issues that face these trout, as well as the importance of evaluating land-uses that have the potential to impact cutthroat habitat. So how is the government planning on dealing with these threats? What is being done to conserve them?

Firstly, I think it would suffice to say that not nearly enough is being done to protect and rehabilitate habitat. The extensive logging and the attempt to allow mining into the area shows this. Resource extraction is still taking a priority over conservation, and very little has been done or is planned to reign in this industrial activity. The government needs to develop a better cumulative land-use plan for the area and consider the big picture when handing out industrial leases. Protecting and conserving habitat needs to be the foundation which cutthroat conservation is built upon, and more needs to be done in this regard.

Westslope Cutthroat Trout Brood Stock

In the past few years, the provincial government has been working towards creating a brood stock of genetically pure Westslope Cutthroat Trout from local populations. Historically, stocked populations of cutthroat in the province have used non-local stocks of hatchery raised cutthroat. Creating a brood stock using local populations ensures the survival of the distinct genetic components that make up our local populations. These unique genetics are the best adapted to the watershed they are found and are considered to be more resilient compared to non-local stocks.

As part of this project, gentically pure westslope cutthroat have been captured during spawning season. These fish remain in streamside holding tanks until enough trout are captured to ensure ample genetic diversity. At this point, the gametes are extracted and fertilized streamside, with different males being crossed with different females. These fertilized eggs are then brought back to the hatchery where the resulting trout are raised. This has been done for the past three years, and the result is a brood stock of genetically pure trout that can be used for stocking efforts, and to bolster populations that are becoming increasingly introgressed with rainbow trout.

Genetically Pure Cutthroat Trout captured for the brood stock.
Hatchery staff fertilizing cutthroat trout gametes after extracting them from genetically pure specimens.

Trickle Down Effect

In conjunction with these efforts, strides have been taken to identify areas suitable for cutthroat trout introductions. These are areas that are protected from rainbow trout invasion (ie. above barriers/culverts), have suitable habitat for cutthroat, and are within the native ranges of cutthroat. The hope is that places such as this can sustain healthy populations of pure cutthroat trout, whose genes will ‘trickle down’ into areas where hybridization occurs. Since the pure genes can move down but the hybridized genes can’t move up, these populations would continually infuse hybridized populations with pure genes.

Upper Oldman River Falls provides a natural barrier that prevents upstream migration of hybridized cutthroat. Above this barrier there are only pure Cutthroat Trout.

Stocking alpine lakes has this same effect, as fish occupying the lake can typically escape down stream but gradients are usually too steep to allow invasion by other fish. Thus, you can maintain genetically pure breeding populations in lakes. This trickle down effect is shown in the Highwood, whereby genetic analysis showed that almost all of the cutthroat genes in the population have their origins from populations that were stocked into the alpine lakes, and not the cutthroat that occupied the stream historically. The difference in that basin is that the cutthroat stocked into those lakes were not from local populations; they came from stocks in BC, Montana, or elsewhere.

This is a good step towards maintaining the genetic integrity of our local populations. Lots of careful planning will have to go into which environments these fish get stocked into, but if the right decisions are made these stocks could become very important moving forward.

Castle Park and Livingstone PLUZ

In 2017, the NDP created Castle Provincial Park. This has helped manage the intensive recreational footprint in the area. On the other side of highway 3 is the Livingstone Public Land Use Zone, which has improved since the implementation of the Livingstone-Porcupine Hills Land Footprint Management Plan in 2018. This land use plan lays out a framework for managing the intensive land use, with particular emphasis on limiting the damage from OHV’s on the aquatic environment. Changes that enforce bridge crossings, limit trails that cross creeks and decommission poorly built trails have all been positive steps towards managing the impact. Data collected over the past five years by ACA will provide the reference point to see if this improved land planning has led to improvements in the cutthroat trout populations. Other changes include the need to buy a public land camping permit, which is a good system to discourage those who are the most disrespectful to our environment (or at least have a reason to ticket them). The camping footprint in the area is still to high, but the permit system is a step in the right direction so long as that money actually gets used to make improvements in the area.

On the whole, there has been many plans, promises, and discussion about making improvements for cutthroat trout, but so far I don’t see too much of a commitment from the government to prioritize it, or do anything to address the underlying habitat problems that result from industry. Until we legitimately protect this area from industry, it will forever be threatened.

Lot’s of positive work has been done; extensive population monitoring, habitat and barrier assessments, and genetic analysis will all aide in the recovery of cutthroat moving forward. The angling community is bigger than ever, providing these streams with an army of protectors that hopefully continue to advocate for these special ecosystems and fantastic fishing opportunities. So long as they are managed properly, they can continue to be a valuable resource for Albertan’s into the future.

In the next post, I will get into to most important part- what you can do as an angler. If these areas are going to continue seeing large numbers of anglers, it is vitally important that people become aware of the threats facing cutthroat and do everything in their power to limit their impact. I’m excited to bring that post to you in the next few weeks. Stay tuned!

Continue reading Part 3 by clicking this link.

Tight lines,



The Alberta Westslope Cutthroat Trout Recovery Team. 2013. Alberta Westslope Cutthroat Trout Recovery Plan: 2012-2017. Alberta Environment and Sustainable Resource Development, Alberta Species at Risk Recovery Plan No. 28. Edmonton, AB. 77 pp.

Mayhood, D.W., 2014. Conceptual framework and recovery guidelines for restoring Westslope Cutthroat Trout populations in Alberta.

Government of Canada. Recovery Strategy and Action Plan for the Alberta Populations of Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) in Canada 2019 [Proposed]

Hurkett, B. H., and J. Blackburn. 2023. Westslope cutthroat trout population monitoring in the upper Oldman River watershed, 2018–2022. ACA Project Report: Final, produced by Alberta Conservation Association, Sherwood Park, Alberta, Canada. 16 pp + App.

Hurkett, B., and K. Fitzsimmons. 2019. Angler survey in the Upper Oldman River watershed. Data Report, produced by the Alberta Conservation Association, Sherwood Park, Alberta, Canada. 17 pp + App.

Blackburn, J. 2008. Population abundance and stock assessment of westslope cutthroat trout in the Upper Oldman River watershed. Data report, D‐2008‐009, produced by the Alberta Conservation Association, Lethbridge, Alberta, Canada. 38 pp.

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