Course:CONS200/2021/Impacts of Climate Change on Pacific Salmon in the Fraser River

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A map depicting the Fraser River's run through the province of British Columbia.

The Fraser River is the longest of its kind in British Columbia, Canada, and is the 11th longest river in the country [1], flowing for a length of 1,375 kilometers [1]. It is located just south of the City of Vancouver. Home to a diverse ecosystem of fish and wildlife, the Fraser River is a main highway transporting all five species of pacific salmon -- Chinook, chum, pink, and sockeye -- to the pacific ocean [2]. The river delta, in particular, is an important breeding ground for fish, as well as thousands of species of birds [3]. It is a flat, marshy area. This delta is important as it retains nutrients from both the freshwater river and the ocean it spills into, and is a resting area for numerous migrating species. Swishwash island, located in the central arm of the Fraser River Estuary, is another pivotal point in the ecosystem, mostly visited by snow goose, bald eagle, and blue heron as a migratory rest area [3].

Unfortunately, however, climate change is steadily destroying the thriving ecosystem [3], specifically the aforementioned species of migrating pacific salmon. The salmon, which are quite vulnerable to the effects of climate change on both the freshwater and oceanic habitats they live in, have had a difficult time adapting to adverse effects of climate change; such as the warming of the waters, change in hydrology in spawning rivers, and a change in the distribution and phenology of predator and prey species [2]. There is evidence to support the theory that these changes in habitat are having negative effects on the growth and survival of pacific salmon in the Fraser River, across all life stages and developmental periods. Salmon can, of course, adapt to climate change -- but not enough to maintain productivity as a species. Changes made to lessen industrial impact, and more focused efforts on conservation in the Fraser River, can help maintain the existence of pacific salmon as an important species in the Fraser River's ecosystem. Pacific salmon hold economic, cultural, and ecological importance in the region, and as such the adverse effects of climate change should be closely monitored.

The Importance of Pacific Salmon in the Fraser River

Drawing of a pink salmon

The Fraser River is Canada's largest river on the west coast and one of the world's most productive salmon rivers.[4]

Chinook, chum, Coho, pink, and sockeye salmon can reproduce in great numbers in the watershed because of the variety of habitats available.

These five species provide ecosystem services such as provisioning, supporting, and cultural services.

Provisioning Services:

Sockeye salmon

Provisioning services are the resources we obtain from the planet, such as plants, animals, and materials. Each of the five Pacific salmon species is sold on open markets at a price that changes based on the season and year. Sockeye salmon, in particular, have historically been an important part of the river's fishery. [5]These fishes are harvested by commercial, First Nation and recreational fishers. From 2005 to 2013, First Nations harvested an average of 843,000 salmon per year, with a high of 1.5 million in 2011 and a low of roughly 375,000 in 2008. The total commercial value of these five species was $5,179,829.48 according to Fisheries and Oceans Canada.[6]

Supporting Services:

Chum salmon
Coho salmon

The basic ecosystem processes, such as nutrient cycling and primary production, which are the cornerstone of ecosystem function, are known as supporting services. Salmon are extremely vital in the ecosystem's nutrient cycling. When juvenile salmon move to the ocean, they bring nutrients from freshwaters with them; when they return as adults, they are several orders of magnitude larger, and they carry nearly entirely nutrients from the marine ecosystem. This helps the entire ecosystem,  to enhanced production for juvenile salmon that emerge the following spring, to increased tree growth and bird density in the adjacent terrestrial landscape.[6]

Cultural Services:

Salmon is a classic example of cultural services, which include recreational and spiritual advantages derived from nature. Salmon are an important element of BC's cultural identity, especially among First Nations peoples. The First Nation people lived in the Lower Fraser are known as Stó:lō people, which translates to “river people”. Salmon is considered as a gift from their Great Creator and be the descendants of a Stó:l ancestor who had been changed into a fish in order for the people to never go hungry.[6] As a result, during ceremonies and spiritual gatherings, the salmon is revered and held in high regard.[7]

Chinook salmon

Another importance is that Fraser River chinook, which are one of the most critical food sources for southern resident killer whales and are in precipitous decline, according to a Canadian independent research committee. When salmon populations are low, it becomes more difficult for many species in the food chain to survive.[8]

The Fraser River serves as a vital resource for at least 138 species along the Pacific coast, including people, for everything from fishing to tourism to transportation. The nature, economics, and culture are all affected by this dependency.[8]

The Impact of Climate Change on the Fraser River Ecosystem

Pacific salmon are anadromous, meaning they spawn and spend a portion of their juvenile lives in fresh water before migrating to the sea to finish the majority of their growth before reaching adulthood.[9] Adult spawners frequently travel hundreds of miles to return to the seas where their parents spawned and were born. Female sockeye salmon lay their eggs in gravel spawning beds scattered across the Fraser River basin in the late summer and fall, the eggs incubate during the winter in the spawning nest, and the fry emerge in the spring, often migrating to a nearby nursery lake.[9]In the spring, fry develop into smolts and move the sea after eating and growing in the lake for a year or two.[9] The parents of young salmon perish as they prepare to join the world.[10] Their bodies rot in the sea or on the shore, where they are consumed by other animals. As a result, they continue to enrich the habitat in which they live.[10]As a result, Fraser River sockeye integrate the effects of climate change across a variety of freshwater and marine environments throughout their life cycle; climatic effects at one stage can affect consequences at another.[9]

Lifecycle of Pacific salmon
A view of the Fraser River, looking east. Viewpoint is the cliff at Westminster Abbey.

The Fraser River has already experienced changes in flow and temperature. Warmer river and ocean temperatures are a result of climate change, and this has a number of detrimental consequences for salmon. Summer mean water temperatures have risen 2.2°C per century over the last 50 years, and are expected to climb another 1.9°C by 2080.[6] Salmon at lower latitudes in B.C. will have "difficulty remaining viable," according to Catherine Michielsens, chief of fisheries management sciences for the Pacific Salmon Commission.[11]Temperatures above 18°C can lower adult swimming performance, while temperatures above 20°C can increase adult pre-spawn mortality and sickness, diminish egg viability, and have legacy effects that harm juvenile health.[12] Higher temperatures can hasten the development of eggs, resulting in a mismatch between prey availability and juvenile development.[6] Infections caused by parasitic, bacterial, and fungal parasites are more likely when the temperature rises.[6] Salmon that move to their spawning grounds during the summer months are more stressed and have less energy reserves, which has a negative impact on swim performance and survival.[12]Moreover, there is fewer zooplankton for salmon to eat.[11] Salmon can die before reaching spawning grounds due to high temperatures in the river. Changes in precipitation, such as dryness followed by heavy rain, can cause landslides, which can harm freshwater habitat. In the face of climate change, Michielsens believes habitat restoration and salmon harvest bans will be insufficient to rescue salmon.[11]

Since 1953, data shows that the spring freshet is coming earlier and reaching half of its yearly cumulative flow nine days earlier than it was a century ago.[6]

Based on modelling done in 2002, changes to the hydrograph of the Lower Fraser River at Hope, BC are projected.[1]Climate change is linked to lower and earlier spring freshet, as well as larger winter flows, because more precipitation is expected to fall as rain rather than snow.[6] This tendency has continued for the next 20 years.[6]By 2099, Morrison predicts that future river temperatures will be 10 times more likely than they are now to cause pre-spawn death in sockeye.[1]

Climate change is already affecting the natural cycles that salmon have evolved to rely on, potentially posing a major threat to their long-term existence.

Potential Solutions to Protect the Pacific Salmon

Fraser River at sunset

This year's Fraser River sockeye run is the lowest in more than 120 years, and the Watershed Watch Salmon Society says it all has to do with climate change [13]. In August 2016, British Columbia pushed efforts combating greenhouse gas emissions to a later date[13], despite growing concerns over wildlife population levels in the region. So what can be done to combat this? In the past, sockeye salmon populations were able to thrive in a more acceptable and moderate water temperature in the river. Due to the impacts of climate change, the mean summer water temperature in the Fraser River has risen as much as 1.5°C [14]. In order to ensure the survival of the salmon population as a whole, we must bring the mean temperature of the river down to an acceptable range for salmon populations. A possible way to do this, if there is access to a deep enough reservoir, is to release deep water reservoirs into the salmon habitats, thereby cooling the ecosystem [9]. Biological responses can help to mitigate the effects of climate change, to a point, as the fish can change morphologically to resist the adverse effects of climate change in a short time period .[9]

Possible Solutions:

In 2007, a study performed for Pacific Fisheries Resource Council followed a hypothetical 150 year timeline, using existing climate data, to conceptualize the adverse effects of global climate change on pacific salmon in the Fraser River[15]. The study provides two possible solution strategy streams to combat the impact of climate change on the salmon in the Fraser River, Hard and soft infrastructure strategies [15]

Hard Infrastructure Strategies

Hard infrastructure strategies allude to implementations on the engineering and technological scale that help the salmon adapt and acclimatize to the new conditions they find themselves in now, with significantly warming waters [15]. Flow rates also play a critical role in the survival of pacific salmon. Maintaining sufficient in-stream flow at appropriate times of the year will protect salmon populations, as these practices can protect natural river-forming practices [15], and improve availability of spawning and rearing habits -- as well as enable upstream migration of mature salmon, reduce vulnerability of salmon to disease, and aid in downstream transportation of juvenile salmon [15]. A possible way to address flow-focused efforts is through water use efficiency. Drip irrigation technology, for example, has good prospects for reducing the amount of water needed for agricultural use [15]. Water recycling and efficiencies are available in industries separate from agriculture, as well.

Soft Infrastructure Strategies

Soft infrastructure strategies pertain to the legal, regulatory, policy, or management oriented approaches that aid in maintaining the watersheds that the pacific salmon populations reside in[15]. These practices include incentives such as water budgeting, which recognizes water as a finite resource with limited long-term renewal, and as such states that water use within a watershed needs to constraints pertaining to annual and long-term yields, or recognizing Aboriginal rights to water and salmon, where first nations tribes in the U.S. and Canada have pushed for the recognition of Aboriginal rights to water and salmon through court action. Soft infrastructure strategies, as opposed to hard infrastructure strategies, aim to protect the watershed through the introduction of laws of regulations, and not through new technology.

Solutions for the future:

How, then, will we as British Columbians protect the Fraser River pacific salmon ecosystem moving forward? Evidence suggests that as a whole, there will be vast losses to the salmon population globally, due to rising global water temperatures [15]. In central BC, however, salmon populations will most likely reside within stable enough population levels. One way that researchers are combating the diminishment of the salmon population is through range expansion, or the moving of a species into space otherwise unoccupied by that species [16]. This allows to directly manipulate salmon stocks to introduce specially bred salmon that possess traits characteristic of resisting the adverse effects of climate change. While technically a successful manner in which to avoid the adverse effects of climate change on the salmon in the Fraser River, the practice is fraught with controversy. The use of salmon hatcheries, and the release of hatcheries-born salmon into the wild, can actually have negative effects on the biodiversity and genetic diversity as a whole. This will in turn have a negative effect on overall population fitness. A largely effective proposition was simply enforcing operating licenses -- mandating these aforementioned licenses can help ensure sustainable resource management, in this case water use.

Another point is further legislative change to protect the salmon population. Here, there are a few options. Firstly, you could adjust the management policies of fisheries, and secondly, establishing the ecosystem's rights to water. This first point focuses mostly on escapement -- or the controlled loss of salmon in fisheries to the wild. This can help salmon better cope with changing ocean and freshwater conditions by ensuring genetic diversity. Ultimately, due to the changes in environment, changes in management would have to enforce less harvesting of salmon in fisheries and push for more escapement. The second point refers to allocating more water rights to ecosystems --neither rivers or the fish that reside in them are seen as bodies worthy of receiving rights, and as such are rarely mentioned in talks of water rights. If, however, there were more water allocated from agriculture or industry and into instream control and water temperature mitigation, then perhaps the pacific salmon in the Fraser River would have a better chance at survival.

The Role of Canada’s Federal Government on the Fraser River: Politics in Climate Change

Current Management Strategies and its Criticisms

Even though Canada is generally seen as a water-rich county, it is still riddled with water-related issues, such as the supply-demand imbalances and policies that are often criticized for being ineffective and inadequate[17]. The main difficulties in the policy creation process are (1) the competition between the consumers of the resource; (2) who the resource should be managed by; (3) the response between the conflicting geopolitical and administrative restrictions against the hydrological restrictions.

The use of water is split between demands for agriculture (ex: irrigation), energy production (ex: hydropower), industry, human consumption, recreation, tourism, indigenous needs, and ecosystem services. The wide range of stakeholders in such a variety of sectors makes it extremely difficult to allocate responsibility. Though environmentalists and first nation groups have been making progress in gaining some power through court and public support, policymaking is still weighted towards economic and industrial groups[18].

Provincially, under the Environmental Assessment Act projects on the Fraser River must have an environmental impact assessment, however, the Environmental Assessment Act[19] only governs the “major projects” meaning that smaller projects that could just be as impactful as larger ones do not need to comply with the act[20]. From 1995 to 2011 mining and energy production projects accounted for 72% of all Environmental Impact assessments and 9% were water management projects like dams, reservoirs or diversions. “Broader land uses and disturbances due to urbanization, stormwater runoff and agricultural activities are not typically subjected to any form of assessment”[20]

The institutional requirements for the watershed cumulative effects assessments and management are:[17]

1.   Lead agency - clear plan with means to monitor and influence decision about land use and developing the project

2.   Mult-stakeholder collaboration - roles and responsibilities of stakeholders involved are clearly defined

3.   Watershed baselines, indicators and thresholds - state of the watershed must be monitored and threshold for impact assessments are stated clearly

4.   Multi-scaled monitoring – Focusing on water quality and quantity, programs are mandated from small scale projects to watershed scales to monitor the land use changes and its affect on the region

5.   Data management and coordination – Monitoring data must be made accessible and common data formats to be viewed and understood by all stakeholders involved

6.   Vertical and horizontal linkages – Transparent and effective communication across management, project assessments and stakeholders must be kept to a high standard.

7.   Enabling legislation – the implementations of the watershed Cumulative assessment and management policies must be met and enforced. Monitoring programs will ensure compliance and influence over development decisions

8.   Financial and human resources – Financial resources must be sufficient to maintain the aforementioned requirements (i.e. monitoring programs, reporting and communication) throughout the duration of the project.

Water Resource Management by the Private Sector

In Canada’s capitalist society, private corporations play an increasingly critical role and responsibility to manage water systems that can have significant affects around the world. Even though, most of Canada’s water is publicly owned, meaning that its managed by the government directly and provisions its goods and services for everyone. However, the private sector is experiencing drastic growth. For the last decades Canadian municipalities have been signing contracts with private corporations to manage water related infrastructure such as water supply, and sewage management[21]. Although in most cases, the municipalities retain ownership of the water system, for-profit private companies’ increasing involvement in water services has been highly controversial[17]. As many argue that water is a basic human right and no for-profit corporations should be provisioning it. In addition to the finance of provisioning water, many residences argue that companies can not be trusted with something as crucial as water and that corporations would prioritize profit over the long-term effects and its influence on nearby habitats and ecosystems. Crucial habitats like the Fraser River basin could be polluted due to unsustainable waste management practices that exclusively focus on making a profit. Although, the provisioning of water resources by private companies are subsidized in an attempt to regulate pricing and make essential resources more equally accessible for all residence, In addition to policies like the aforementioned Canadian Environmental Protection Act[19] are in place to ensure safe and sustainable management of the water resources, many privatization opponents still argue that the system is susceptible to corruption through lobbying[17].


Fraser River, Chilliwack, BC - Salmon Run

The Fraser River is a diverse, thriving ecosystem, which is home to many different species of fish and other wildlife. Pacific Salmon in the Fraser River has significant importance due to their ecosystem services such as provisioning, supporting, and cultural services. They had been an important part of the river's fishery, First Nation and the ecosystem in  Fraser River. All Pacific salmon are anadromous, meaning they begin their lives in freshwater, migrate to the ocean, and then return to reproduce and die there. However, climate change has led to changes in flow and temperature. Water becomes warmer over the last 50 years. The spring freshet is arriving sooner and reaching half of its annual total flow nine days earlier than it was a century ago. These changes made by climate changes are posing a major threat to salmon in long-term existence.

Pacific Salmon

The threat of global climate change seriously impacts and encroaches upon the region, however through the continued efforts made by the province of British Columbia and its citizens, change can be made to ensure the survivability of the pacific salmon population that inhabits the Fraser valley. At the present, with the implications of both hard and soft infrastructure strategies, salmon populations remain under careful scrutiny. Moving forward, the citizens of British Columbia can campaign against fierce industries that promote the adverse effects of climate change on the pacific salmon in the river, such as agriculture and commercial fishing. With the continued push for more intensive water rights, as well as changes in management for the aforementioned industries, the future of the pacific salmon just may persevere. Though, valid concerns are on the rise due to the increase of privatized corporation’s influence over water resources and management. Where critics warns of potential mistreatment of the environment due to prioritization of profit and the lack of protection and policy enforcement by the government, with concerns of corruption and corporate lobbying.


  1. 1.0 1.1 1.2 1.3 Morrison, J., Quick, M. C., & Foreman, M. G. (2002). Climate change in the Fraser River watershed: flow and temperature projections. Journal of Hydrology, 263(1-4), 230-244.
  2. 2.0 2.1 Hinch, S. G., Healey, M. C., Diewert, R. E., Henderson, M. A., Thomson, K. A., Hourston, R., & Juanes, F. (1995). Potential effects of climate change on marine growth and survival of Fraser River sockeye salmon. Canadian Journal of Fisheries and Aquatic Sciences, 52(12), 2651-2659.
  3. 3.0 3.1 3.2
  4. "Quantifying lost and inaccessible habitat for Pacific salmon in Canada's Lower Fraser River". Freshwater Ecology. 08 July 2021. |first= missing |last= (help); Check date values in: |date= (help)
  5. Richmond Chamber of Commerce with the assistance of D.E. Park & Associates Ltd. (July 2014). "THE ECONOMIC IMPORTANCE OF THE LOWER FRASER RIVER" (PDF).
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Dave Scott, Ross Dixon, Misty MacDuffee, with support from Riley Finn and Kristen Walters. (March 2020). "Toward a vision for salmon habitat in the Lower Fraser River".CS1 maint: multiple names: authors list (link)
  7. "The Stó:lō "People of the River"".
  8. 8.0 8.1 Young, Jeffery (September 22, 2019). "The mighty Fraser River and its once abundant salmon are on the edge".
  9. 9.0 9.1 9.2 9.3 9.4 9.5 Healey, M. (2011). The cumulative impacts of climate change on Fraser River sockeye salmon (Oncorhynchus nerka) and implications for management. Canadian Journal of Fisheries and Aquatic Sciences, 68(4), 718-737.
  10. 10.0 10.1 Pacific Salmon Foundation 2021. "Species & Lifecycle". Pacific Salmon Foundation.
  11. 11.0 11.1 11.2 Wood, Stephanie (Aug. 17, 2020). "Four reasons 2020 is set to see the lowest Fraser River sockeye salmon return on record". Check date values in: |date= (help)
  12. 12.0 12.1 Sue C.H. Grant, Bronwyn L. MacDonald, Mark L. Winston(2019).State of Canadian Pacific Salmon: Responses to Changing Climate and Habitats. Canadian Technical Report of Fisheries and Aquatic Sciences 3332. p.13
  13. 13.0 13.1 Morton, B. (2016, Aug 20). Fraser sockeye run at lowest level recorded; pacific salmon commission blames 'grim' numbers on climate change. The Vancouver Sun Retrieved from
  14. MARTINS, E. G., HINCH, S. G., PATTERSON, D. A., HAGUE, M. J., COOKE, S. J., MILLER, K. M., LAPOINTE, M. F., ENGLISH, K. K., & FARRELL, A. P. (2011). Effects of river temperature and climate warming on stock-specific survival of adult migrating fraser river sockeye salmon (oncorhynchus nerka). Global Change Biology, 17(1), 99-114.
  15. 15.0 15.1 15.2 15.3 15.4 15.5 15.6 15.7 Nelitz, M., Xwi7xwa Collection, & Pacific Fisheries Resource Conservation Council. (2007). Helping pacific salmon survive the impact of climate change on freshwater habitats: Case studies : Perspectives from the okanagan, quesnel, nicola, cowichan, nass, and englishman river watersheds. (). Vancouver: Pacific Fisheries Resource Conservation Council.
  16. [ "natureportfolio"] Check |url= value (help). Nature.
  17. 17.0 17.1 17.2 17.3 Bakker, Karen (2007). "Eau Canada:The Future of Canada's Water". Eau Canada:The Future of Canada’s Water.
  18. Renzetti, Steven (2017). Water Policy and Governance in Canada. Springer International Publishing. ISBN 3-319-42805-5, 978-3-319-42805-5 Check |isbn= value: invalid character (help).
  19. 19.0 19.1 "Water governance: federal policy and legislation". Government of Canada. December 9, 2021.
  20. 20.0 20.1 Stephanie, Kristensen; Noble, Bram; Patrick, Robert (2013). "Capacity for Watershed Cumulative Effects Assessment and Management: Lessons from the Lower Fraser River Basin, Canada". Environmental Management. doi:10.1007/s00267-013-0075-z.
  21. Finger, Matthias (2002). Water Privatisation: Trans-National Corporations and the Re-Regulation of the Water Industry. USA and CANADA: SPON PRESS. ISBN 0-203-30248-6.

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