Industrial DevelopmentSalmon and industry share the same watersheds
Forestry, agriculture, and mining are a few of the industries that have reshaped salmon watersheds – the future of salmon may rest on how we grow them.
Industrial development can affect salmon in many ways, including indirectly by changing the landscapes that surround salmon-bearing waters. Salmon depend on healthy watersheds – areas of land where rain, snowmelt, and groundwater drain into a common river – for clean, cool, and consistently flowing water.
Industrial activities in a watershed can affect water quality and change hydrology, the natural movement of water through the environment. These changes may include lower river flows, higher peak flows, warmer water temperatures, increased erosion, and shifts in the timing of seasonal runoff. Pacific salmon have evolved alongside the natural hydrology of their watershed over thousands of years, and sudden changes to these patterns can be a major challenge for their survival.
Forestry operates in every salmon watershed
Salmon and forests are deeply interconnected. The bodies of spawning salmon deliver marine nutrients into coastal forests, while forested watersheds provide the cool, clean rivers and lakes salmon need to survive. Beginning in the late 19th century, industrial logging spread rapidly across B.C. and now affects nearly every major salmon watershed in the province.
A clear-cut impact on salmon habitats
Logging’s Legacy on Haida Gwaii
On Haida Gwaii, where industrial logging began in the 1920s, residents witnessed widespread destruction of salmon habitat over the following decades. In logged watersheds, seasonal floods became more frequent and intense, destroying deep pools formed by fallen trees where juvenile salmon once reared. These high flows also washed away salmon eggs, reducing survival of the next generation.
Logging and road construction on steep slopes increased erosion and the frequency of landslides.† Sediment from these disturbances clouded rivers, smothered spawning habitat, reduced water quality, and in some cases physically blocked salmon from reaching their spawning grounds. By 2004, the Ain River on Haida Gwaii – once known for large sockeye runs – was described as “barren of sockeye”.† Although stronger forest protections exist on the islands today, the long-term future of many salmon populations remains uncertain.
Forests Do More Than Grow Trees
The changes seen in Haida Gwaii are typical: when forests are no longer there to retain water and slow down its movement, the highest flows become higher and the lowest flows become lower.† Both extremes are problematic for salmon, who time their migration and life cycle with the patterns of hydrology that existed for millennia before logging began and depend on consistent flowing water to migrate from spawning grounds to the ocean and back.
Forestry can also increase stream temperatures if adequate riparian buffer zones – areas along streams that provide shade, nutrient inputs, and fallen wood to create pools – are not left behind.† These changes don’t just affect one generation of salmon – research has showed that the impacts of logging a watershed unfold over several decades, with the long-term effects sometimes being more harmful than immediate ones.†
Preserving the Buffer Against a Harsher Climate
Old-growth forests are particularly valuable for biodiversity, climate resilience, and salmon habitat, and yet old-growth logging continues today.
Many of the province’s most productive valley-bottom old-growth forests – the forests most closely connected to salmon-bearing streams – have already been heavily logged or remain vulnerable to harvest. Recent old-growth deferral initiatives and Indigenous-led conservation efforts have increased attention on the need to better protect remaining intact forests, but how much old growth should remain and whether forestry practices can adapt fast enough to offer protections are open questions. As climate change intensifies droughts, floods, and warming, the loss of old-growth forests is a major long-term threat to the resilience of Pacific salmon watersheds.
How logging helps seals hunt salmon
When trees are harvested in coastal B.C., the wood is often stored as log booms – floating bundles of logs in estuaries, large rivers, and sheltered coastal areas.
Though convenient for transportation, log booms are harmful to the estuary habitat that many species of salmon rear in as juveniles.† They can be used as haul-outs for harbour seals, who are natural predators of salmon, providing a constant and abundant space for large groups to gather in estuaries. Seals are excellent at finding and exploiting choke points in salmon migration routes where large numbers of salmon gather without shelter and wait to pass. When log booms provide opportunities to ambush salmon at such choke points, the impact of these predators can grow far beyond what would occur naturally.
Though they have been present in some estuaries for up to 100 years, the impacts of log booms may be intensifying as seal populations grow and climate change forces salmon to wait longer for good migration conditions in freshwater.
Different Places, Different Pressures
The opportunities to build smarter with salmon in mind depend on what the major industries are, which varies among regions.
Agriculture | Fraser
Human settlements have historically been built along rivers and floodplains, where fertile soils and access to water support farming.
But these same floodplains are also critical salmon habitat. Naturally connected side channels, wetlands, and seasonally flooded fields provide slow-moving, food-rich environments where juvenile salmon can grow before migrating to sea.
The Fraser Valley, including what are now Abbotsford, Langley, and Chilliwack, was once an expansive floodplain seasonally connected to the Fraser River. Through the 19th and 20th centuries, dikes, floodgates, and pump stations were built throughout the lower Fraser Valley to protect agricultural land and growing communities from flooding. As a result, local salmon populations have lost an estimated 85% of their floodplain habitat, which juvenile salmon use to grow and find refuge.† Much of the remaining habitat is now affected by chemical contamination, warmer water temperatures, and flow changes from urbanization and water withdrawals.
In recent years, efforts have emerged to reconnect salmon with their floodplain habitats in ways that benefit both ecosystems and local communities. As flood control infrastructure ages, it can be rebuilt fish-friendly, with pump stations and floodgates salmon can pass and wetlands that soak up floods. In California, researchers experimented with using seasonally flooded rice fields as juvenile salmon habitat – and both the fish and crops grew stronger.† PSF and partners are working with Fraser Valley farmers on the same idea.
Lower Fraser floodplain habitat, 2024. Photo: Braela Kwan.
Dams | Columbia
More than 80 major dams have been built in B.C. and the Yukon to generate hydroelectric power, provide flood control, or store water for municipal and agricultural uses.
Most were built without salmon in mind, with fish passage added later, and several remain hard barriers to fish migration. On the Columbia, major dams in Canada and the U.S. blocked salmon for over 80 years, wiping them out of much of their historic range. Former sockeye and Chinook habitat in the Kootenay region is still cut off from the ocean today but in other parts of the Columbia region, salmon are recovering. On the Okanagan River, downstream of the biggest dams, sockeye have rebounded, helped by better fish passage at dams, habitat work, and hatchery programs – work done by partners on both sides of the Canada – U.S. border.†
Mining | Northern Transboundary
Mining can take many forms, but often involves diverting or extracting large amounts of water and processing ore in ways that generate toxic waste products.† These wastes are commonly stored in tailings ponds and containment dams that can persist long after mines close, creating long-term risks to salmon-bearing watersheds. Failures of these systems can release contaminated water and sediment into rivers and lakes, with potentially severe consequences for salmon habitat and water quality.
In the Northern Transboundary Region of B.C., rich deposits of gold, copper, silver, and other minerals have driven extensive mining development in the headwaters of major salmon rivers, particularly in the Stikine, Taku, and Unuk watersheds. In some tributaries of the Stikine River, mining tenures overlap with as much as 88% of the watershed area connected to salmon habitat.† Concerns over regulatory oversight intensified after the 2014 Mount Polley disaster, when a tailings dam breach released millions of cubic metres of mine waste into central B.C. lakes and rivers† – and a similar failure at the Yukon’s Eagle Gold mine in 2024 shows these are not one-off events.†
Despite this history, pressure to expand mining in salmon watersheds continues to grow. In 2025, a proposed expansion of a mine in the Stikine headwaters was included on a list of industrial projects to be fast tracked, despite concerns that aspects of its tailings system resembled conditions identified at Mount Polley before its failure.† The high price of gold and rising demand for critical minerals used in clean energy technologies is increasing pressure to develop or reopen mines across western Canada – including in watersheds that may become increasingly important climate refuges for salmon in the future.† This growing conflict highlights the need for strengthened environmental protections and responsible mining practices that safeguard salmon.
Photo: Manu Keggenhoff
Adding It All Up
In nearly every Pacific salmon watershed, multiple industries operate simultaneously, each altering the water quality, flows, habitat connectivity, and ecological conditions salmon depend on.
The scale and impacts of these industries vary widely. Some activities, such as poorly managed mining projects or dams, can devastate individual salmon populations or entire river systems in a short period of time. Others, such as forestry, agriculture, and urban development, often create slower but widespread problems across large portions of salmon habitat. Together, the cumulative effects of industrial activities and their associated infrastructure – roads, dikes, culverts, dams, pipelines, and water withdrawals – represent one of the greatest threats to salmon freshwater ecosystems.
The Hopeful Part
Unlike some of the other challenges salmon face, the impacts of industrial development can be reduced through thoughtful planning and management.
Pacific salmon have evolved to overcome disturbances and are remarkably resilient when watersheds remain clean, cool, and connected.
Protecting and restoring these conditions – through better land-use planning, habitat protection, fish-friendly infrastructure, and watershed-scale management – can allow salmon and human communities to coexist. The future of salmon will depend not only on reducing individual impacts, but on recognizing how multiple pressures combine across entire landscapes.
Industrial development isn’t going away. With smarter planning, salmon don’t have to either.
