Biodiversity, Pacific Coast, Science, Water, Wetland restoration, Wetlands

Coming of age on the edge of the ocean

How moving sediment benefits juvenile salmon

By Chantelle Abma March 31, 2025

A DUC staff member walks along the temporary pipeline that brings sediment to the foreshore of the Fraser River Estuary.

Like human teenagers, juvenile salmon need spaces to grow into the mature fish they will become; ready to take on the saltwater ocean, and eventually return to their freshwater spawning grounds. But these transitional spaces are challenging to find.

The Fraser River Estuary—one of North America’s most important salmon ecosystems—has lost vast expanses of tidal marshes, crucial spaces that provide juvenile salmon with food and shelter during a critical transitional phase of their lives. Without these habitats, survival rates drop, threatening salmon populations and the species, communities, and cultures that rely on them.

To restore these critical spaces, Ducks Unlimited Canada (DUC) and its partners are reshaping the coastline through the Sturgeon Bank Sediment Enhancement Pilot Project. Entering its fourth year, the project repurposes sediment dredged from the Fraser River—material that would otherwise be lost to the ocean—by strategically placing it into the estuary where much of it would have naturally built up if human-made interventions like dikes and jetties weren’t present. This additional sediment creates a stronger foundation for tidal marshes, rebuilding and reinforcing them.

The sediment was dredged from a local marina at night to complement the tide schedule. © Ducks Unlimited Canada

A new foundation for young salmon

This past fall, sediment from the Deas Basin BC Ferries Fleet Maintenance area was transported by barge and dispersed at Sturgeon Bank via a floating pipeline. This method minimizes disruption while allowing natural tidal forces to distribute the sediment, mimicking historical processes that once nourished these marshes.

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Tidal marshes are like nurseries for young salmon. They provide food, shelter, and protection from predators during a critical stage of development. Without these safe havens, fewer salmon make it to adulthood.

Eric Balke, senior restoration biologist, Ducks Unlimited Canada

Since the project began, over 21,000 cubic metres of sediment have been placed in select locations to help raise the elevation of this habitat and aid in the restoration of these marshes. The benefits extend beyond salmon—shorebirds, waterfowl, and marine life also depend on these ecosystems, and healthy tidal marshes help buffer coastlines from storms and rising sea levels.

Restoring the balance

The loss of sediment in the Fraser River Estuary is a consequence of human activities such as the addition of river training structures, dredging, and development. Sturgeon Bank alone has lost an estimated 395 acres (160 hectares) of tidal marsh since the 1980s—equivalent to 40 BC Place Stadiums.

Using a 1.4-kilometre floating pipeline, rather than heavy machinery, allows sediment to be placed strategically, letting tides, currents and waves naturally disperse it. “This floating pipeline lets us move sediment efficiently while protecting the delicate estuary,” said Piet Greven of Fraser River Pile and Dredge, the contractor that completed the sediment pumping. “We’re developing sustainable methods that could be used in other regions.”

Sediment is delivered to the pre-selected location via temporary pipeline. © Ducks Unlimited Canada

A blueprint for the future

The Sturgeon Bank project is part of the larger Restore Fraser River Estuary Salmon Habitat (ReFRESH) initiative, led by DUC in collaboration with Raincoast Conservation Foundation, the Lower Fraser Fisheries Alliance, and Asarum Ecological Consulting. Funding is provided by The Government of Canada and the Province of British Columbia through the BC Salmon Restoration and Innovation fund, with additional support from Nature Force.

As monitoring continues, DUC and its partners aim to expand these efforts across the Fraser River Delta, creating a resilient network of tidal marshes that will support salmon populations for generations.

An aerial view with the mound in centre, new sediment has been added here causing a rise in elevation. © Ducks Unlimited Canada

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The Fraser River Estuary is at the heart of the salmon lifecycle. By restoring these critical habitats, we’re not just helping salmon—we’re strengthening entire ecosystems, coastal resilience, and the communities that depend on them.

Eric Balke, senior restoration biologist, Ducks Unlimited Canada