Fish Sector in the Blackfeet Climate Change Adaptation Plan

Flyfishing by tribal members_Coy Harwood
Photo by Coy Harwood.

The Fish chapter of the 2018 Blackfeet Climate Change Adaptation Plan (BCCAP) is one of eight chapters created for the first formal, multi-sector climate change adaptation planning effort in the Blackfeet Nation, following the process described here. This chapter was developed through meetings with managers from the Blackfeet Environmental Office and the Blackfeet Fish and Wildlife Department, and then revised through face-to-face, telephone, and email correspondence. The first two sections, observed impacts and expected impacts, are sets of working hypotheses about climate change that are based on day-to-day observations and/or interpretations of climate change literature (e.g. the Montana Climate Assessment). These hypotheses were formed for the purposes of assessing climate change vulnerability and then strategizing adaptation goals and actions. This and other sections of the plan will be revisited and updated periodically as action items are implemented and adaptation efforts produce insights for future planning.

For planning purposes, the focus of the fish sector is fish and fish habitat, with the intent to assess and create the benefits of healthy functioning fish habitat in the context of climate change. This planning area includes bodies of water and substrate required for fish spawning, breeding, feeding, and growth which are located on and near the Blackfeet Reservation. The geographical impact is expected throughout Montana. The timeframe for these expected changes are estimated to be in the near-term (0-10 years), though long-term impacts must be considered as well.

Observed impacts

Lake and stream water levels are lower due to warmer days. Algae has increased as a result of reduced water levels and warmer water temperatures, plus added nutrients. The warmer water temperatures are detrimental to trout.  Some people who fish have observed that the warmer water temperatures affect fish biting and the quality of the fish. In warmer waters, people have found the fish meat itself is mushy compared to when the waters are colder. A lot of people engage in catch-and-release fishing, but when they are fishing in hotter weather, the fish are less likely survive a release attempt, and some people who fish say they do not like to fish in hotter weather because they are concerned about fish survival.

Expected Impacts

Impacts on fish

The effects of climate change on fish and other aquatic species include loss of habitat, reduced flows, and higher water temperatures. Climate change impacts can be compounded by locally-driven impacts, for example, roads and timber sales.

Warming water temperatures will impact fish and fish habitat. Climate change will increase water temperatures, in lakes and streams, with resulting lower levels of dissolved oxygen. Concerns about fish disease will increase. Climate change is also expected to stress macroinvertebrates. High water temperatures are also detrimental to fish not only from a physical aspect but from the increase in toxicity from pollutants such as ammonia. The toxicity of ammonia is a function of pH and temperature. Increases of both are bad for the fish.

Streams are projected to warm differentially, with larger temperature increases in lower elevations and smaller increases in the coldest streams. Since Salmonid species such as bull trout and cutthroat (including Westslope Cutthroat Trout, also found in the Blackfeet Nation) require colder water temperatures, they will likely be impacted by warming temperatures.

Fall colors and creek_Kim
Climate change may cause streams to warm, making them less suitable habitat for native fish species. Photo by Kim Paul.

Cold-water habitats for Salmonids are predicted to decrease in the future, including for cutthroat trout and bull trout.1

Nonnative fish like brook trout, brown trout, and rainbow trout often displace cutthroat and bull trout. Brook trout tolerate colder temperatures like cutthroat, but brown trout and rainbow trout will still find places where the temperatures are too cold for their habitat, leaving some refugia for cutthroat.2

Climate change will increase variation in the timing and rates of water flow, impacting fish. This is because climate change is driving earlier snowmelt, high midwinter floods, and reduced snowpack. Peak flows (and floods) may damage fish redds if scouring flows occur when eggs are in the gravel or newly hatched fish are emerging.3 Decreased snowpack is projected to impact fish by decreasing summer low flows by and shifting the timing of peak flows. A shift in the timing of peak runoff will impact fish spawning. Lower flows combined will warmer air temperatures will increase stream temperatures. Higher stream temperatures and competition from non-native fish will reduce cutthroat trout and bull trout abundance.4

Impacts by wildfire

Wildfires will impact fish and fish habitat. Wildfires are predicted to increase, increasing stream sediment, increasing peak flows and channel scouring, and raising stream temperatures by decreasing vegetation.5

Potential consequences of impacts

Not responding to the impacts of climate change will result in the loss of bull trout, especially if the headwaters are not protected. If fishing is not regulated and catch-and-release fishing is not stopped during high temperatures, fish populations could decline. Without appropriate action, there is an increased risk of invasive plant species in water. Without appropriate action in the face of climate change, recreational fishing opportunities could be negatively impacted or lost. The Blackfeet Reservation is currently a renowned fishing destination and a huge revenue source for the tribe as a whole, and climate change impacts to fish could harm the whole tribe.

St Maries Lake.JPG
Fishing on St. Mary Lake. Photo by Coy Harwood.
Fish Assessment

Location of concern
The location of concern is Reservation-wide.

Probability of impacts to fish
Climate change is already negatively impacting fish, and there is a high probability it will negatively impact fish in the future.


Potential consequences of impacts
The potential consequences are high.



Very high

Adaptive Capacity
The adaptive capacity is low because fish and fish habitats are already stressed from factors not directly related to climate change. For example, the St Mary Diversion Dam functions poorly, resulting in the taking of fish.  Connectivity is decreasing due to loss of stream habitat from warming water temperatures and dams. Additionally, reconnecting stream habitat is risky when weighed against the risk of invasion from non-native species. Furthermore, roads often follow streams and rivers, meaning that the trees that could normally provide shading to cool aquatic habitats are missing and not easily replaced. Increasing threats from aquatic invasive species like zebra mussels will be a thing to watch. Harmful algal blooms (HABs) are also a concern because they can result from higher water temperatures and increased nutrients from animal waste and dead plant material. HABs can create hypoxic zones and toxins that can kill fish.



Estimated Risk

The priority for implementing climate change adaptation actions is high given that there is both high risk and high vulnerability.

Fish Adaptation Strategies: Goals and Actions

Responsible party
The Blackfeet Fish and Wildlife Department and the Environmental Office are responsible for creating and implementing adaptation strategies to protect fish and fish habitat. The Blackfeet Fish & Wildlife Department is currently in the process of hiring a fisheries biologist who could increase focus on protecting fish and fish habitat.

Purpose (Goals)
The purpose is to assess and create the benefits of healthy functioning fish habitat, with three goals:
1) Assess quality and quantity of fish habitat in lakes and streams
2) Ensure healthy habitat for fish and maintain healthy fish populations
3) Protect recreational fishing opportunities.


The priority for fish population and habitat management is high.

Preparedness goals: strategies and actions

Goal 1: Assess quality and quantity of fish habitat in lakes and streams

a) Hire a fisheries biologist to implement a monitoring program

1) Decide on key indicators and routinely measure them (e.g. water temperature, water levels, water flow, dissolved oxygen, etc.)

b) Hire a hydrologist to manage water resources for uses other than agriculture and irrigation

c) Identify and monitor what fish are in what lakes and streams

1) Net fish to determine what fish type, age, size, and quantity are in the lakes and streams and to determine whether the food supply is good

Goal 2: Ensure healthy habitat for fish and maintain healthy fish populations

a) Increase communication and cooperation among the departments most responsible for fish habitat, while engaging the Tribal Council: Environment (water quality), Water Resources (water quality), Fish & Wildlife, and Forestry

1) Consult with the Nonpoint Source Program, which has a management plan with best management practices to reduce habitat impacts which could benefit fish habitat

b) Hire a fish biologist

c) Maintain and restore stream structure and function

1) Restore floodplains and channels so they store cool water
2) Ensure effective passages for aquatic organisms, and include fish ladders on impassable dams and diversions
3) Restore riparian vegetation
4) Maintain or restore American Beaver populations

d) Maintain higher summer flows and mitigate effects of lower flows

1) Increase the Fish & Wildlife Department’s understanding of secured water rights under the new Water Rights Compact and seek possibilities for increasing instream flows
2) Understand the amount of water withdrawals for human use from within Reservation boundaries, and decide how much water should be retained for fish
3) Allow for more water to flow from regulated water bodies during low flow periods
4) Investigate creating a reservoir on the Willow Creek stream to help with flooding and to maintain water for later use
5) Explore the possibility of building beaver dam analogues (beaver mimicry) to increase natural storage and repair riparian habitat

e) Remove or relocate roads away from stream channels and floodplains, where especially sensitive

f) Reduce interactions between native and nonnative fish species

1) Facilitate movement of native fish to streams with suitable temperatures
2) Increase the size of suitable habitat wherever possible
3) Reduce nonnative fish species by increasing harvest of nonnative fish (e.g. encourage sport fishing; manually or chemically remove non-native fish)

g) Manage grazing to restore riparian systems

1) Monitor and adhere to standards and guidelines for water quality
2) Protect stream and lake edges from cattle grazing (e.g. improve water quality by using fencing)
3) Reduce cattle in riparian areas
4) Provide off-stream or off-lake (water body) water sources for livestock

h) Reduce the frequency and severity of fires where appropriate and possible

1) Reduce hazardous fuels
2) Employ erosion control structures after a fire (e.g. use water checks like logs, large boulders, etc.)

i) Protect redds from scouring after heavy precipitation

1) Use erosion control structures (e.g. water checks like logs, rocks, etc.) after big rain events to prevent erosion

j) Protect streams and lakes from harm by all-terrain vehicle recreational use

1) Minimize use by recreational vehicles in stream beds and lake edges
2) Educate recreational users about the impacts they can have on fisheries and fisheries habitat
3) Prevent recreationists from creating new roads

k) Address invasive species that effect habitat health

1) Establish and sustain check stations to reduce invasive populations
2) Evaluate lakes and streams to understand distribution of native species

l) Develop a native fish hatchery to bolster local populations

1) Update existing fish hatchery plans

m) Alter fishing regulations and practices to protect native fisheries

1) Possibly close waters to fishing when the temperatures are so high that it causes more stress to the fish than would be healthy for them
2) Educate the public on best fishing practices
3) Investigate ending gill-netting in other water bodies. (Gill-netting is not allowed on St. Mary Lake due to bull trout in that system.)
4) Bolster enforcement

n) Protect and restore headwater habitat

1) Coordinate with relevant managers to prevent cutting of forests and grazing near headwaters streams
2) Stream restoration/stabilization of degraded streams
3) Prioritize watershed restoration in the most important places, using climate change model predictions

o) Protect cold stream temperatures in the summer

1) Narrow unnaturally widened channels
2) Restore and maintain stream shade
3) Limit grazing in some areas

p) Manage connectivity

1) Weigh the advantages and risks of temporarily or permanently removing barriers for native fish to permit them to move to new or previous habitat, recognizing that removing barriers may allow colonization by nonnative fish

q) Possibly assist migration to unpopulated water bodies. Only do this after weighing potential impacts to other species (i.e. How would moving cutthroat to a new water body impact amphibians or invertebrates?)

r) Implement the Blackfeet Nation Bull Trout Management Plan that was developed in coordination with the U.S. Fish & Wildlife Department.

Goal 3: Protect recreational fishing opportunities

a) Reevaluate fish populations by understanding stocking and take levels, working jointly with Montana Fish, Wildlife & Parks and the U.S. Fish and Wildlife Service

1) Conduct fish surveys

b) Evaluate habitat health of lakes and waterways

1) Work with Water Resources (water quality) and Environment (water quality), and fish biologists to assess biotic and abiotic conditions

c) Address invasive species that effect habitat health

1) Establish and sustain check stations to reduce invasive populations
2) Evaluate lakes and streams to understand distribution of invasive species

d) Stock fish when appropriate

Required and Existing Authority/Capacity
Tribal Council has the required and existing authority/capacity to implement the preparedness actions, as does the Blackfeet Fish and Wildlife Department and, to some extent, the Environment Office. The loss of habitat and changes from locally-driven impacts, such as roads and timber sales, compounds climate change impacts. However, the locally-driven direct impacts can be mitigated by management practices, but they have to be implemented by Council action and then enforced by the tribal Departments such as Tribal Forestry and Fish and Wildlife. Reduced flows can be mitigated somewhat on regulated water bodies.

Partners and Potential Funding Sources
Partnerships help ensure the health of fish and fish habitat and are integral to enacting preparedness goals and actions. Partners include the Blackfeet Environmental Office, Blackfeet Fire Management (Forestry), Montana Fish Wildlife and Parks, U.S. Fish and Wildlife Service, the Bureau of Reclamation, the Province of Alberta, and Glacier National Park. There is a need to work hand-in-hand with the U.S. Fish and Wildlife Service and Glacier National Park in order to protect and maintain bull trout habitat and to implement the Blackfeet Nation’s bull trout management plan. There is also a need to work with the Bureau of Reclamation and U.S. Fish and Wildlife Service to address the poorly-functioning St Mary Diversion Dam. The Dam is currently causing fish losses downstream, including illegal take of bull trout. The Water Rights Oversight and Implementation Committee may have ideas on how to use some of the Tribe’s water rights to improve habitat for fish.

Funding needs for addressing the estimated impacts
Potential funding sources for addressing the estimated impacts include the Water Compact damage claim funds, hydro power mitigation funding, and other grant funding. Funding needs and sources for addressing the estimated impacts to fish are to be determined.

Existing Programs that Contribute towards Resilience
There are a variety of existing activities by the Blackfeet Nation that are already building the resilience fish and fish habitat to climate change. Here are a few examples:

  • The Water Compact was enacted in 2017, clearly defining the Tribe’s water rights, and making management more feasible.
  • The Blackfeet Fish & Wildlife Department regulates fish taking by only allowing catch-and-release in some of the streams and by restricting the times of day fish can be taken.
  • The Blackfeet Nation is a top fly-fishing destination. This means that the Fish & Wildlife Department has a large group of stakeholders who value the health of the Reservation’s fisheries. What’s more, there is evidence that fly fishermen are self-regulating during hotter temperatures by refusing to fish in times they believe would stress released fish.
  • The dam at Midvale protects native fish from interacting with non-native fish.

Go to the next section: Forestry

Go back to the Climate Change Adaptation Plan Home Page

Literature Cited

Halofsky, Jessica E., David L. Peterson, S. Karen Dante-Wood, Linh Hoange, Joanne J. Ho, and Linda A. Joyce. “Climate Change Vulnerability and Adaptation in the Northern Rocky Mountains.” Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, 2017.


[1] Jessica E. Halofsky et al. (2017), “Climate Change Vulnerability and Adaptation in the Northern Rocky Mountains”, Forest Service U.S. Department of Agriculture, Rocky Mountain Research Station.

[2] Ibid.

[3] Ibid.

[4] Ibid.

[5] Ibid.


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