Pacific Coast, Partnerships, Science, Water

Reviving Sturgeon Bank: A new vision for marsh restoration

An ambitious pilot project is aimed at reclaiming lost ground and restoring the marsh to its former footprint

March 30, 2024

A second year of work has wrapped up for the Sturgeon Bank Sediment Enhancement Pilot Project in the Lower Mainland of British Columbia. The pilot project is aimed at restoring tidal marsh in an innovative and sustainable way while, among other goals, combating sea-level rise and coastal biodiversity loss.

Disappearing tidal marsh

Over the past four decades, the Sturgeon Bank tidal marsh has undergone a drastic reduction in area, losing approximately 30 per cent of its original expanse. This decline raises significant concerns about the future health of the marsh, but what factors contribute to this concerning trend?

Upon close examination, four key factors emerge as the likely primary drivers of the marsh’s decline:

Sediment deficit: River-training practices, including the construction of structures such as jetties and human activities like dredging, have altered the delta’s dynamics. These interventions disrupt the natural sediment movement essential for marsh vitality. Over time, the resulting sediment deficit has severely impacted the marsh’s ability to thrive and regenerate.
Sea-level rise: Coastal infrastructure, including dikes, constrain the marsh’s ability to adapt to sea-level rise resulting in a phenomenon known as coastal squeeze. This restricts space for marsh migration, accelerating habitat loss.
Goose abundance: Intense grazing by migratory snow geese and invasive resident Canada geese greatly impact marsh vegetation, accelerating its degradation. The burgeoning population of these waterfowl further exacerbate the challenges faced by the marsh ecosystem.
Salinity: Alterations in the delta through river-training structures have not only constrained the natural flow of freshwater but also reduced the mixing of fresh with salt water, leading to increased salinity levels within environments like the Sturgeon Bank tidal marsh. These elevated salinity levels are one likely driver of the marsh’s declining area.

The project was featured by Global News Hour

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Project restores vital marsh habitat in Richmond

Active sediment deposit on Sturgeon Bank in 2024 © Fernando Lessa

The pilot project: One person’s scraps are another’s starting point

The Sturgeon Bank Sediment Enhancement Pilot Project is an ambitious endeavor aimed at reclaiming lost ground and restoring the marsh to its former footprint. Developed over 12 years of meticulous research and planning, this innovative project represents a paradigm shift in marsh restoration.

Led by Ducks Unlimited Canada, this project leverages new techniques to replenish the marsh’s sediment and is possible with funding from the Department of Fisheries and Oceans Canada and the Province of British Columbia, with further support from Tsawwassen First Nation, Raincoast Conservation Foundation, Lower Fraser Fisheries Alliance, Pacific Salmon Foundation, the Vancouver Fraser Port Authority and The Nature Force. By strategically depositing material dredged from the Fraser River, the project seeks to simulate natural sedimentation processes, fostering the regeneration of the marsh ecosystem.

Dredging the Fraser River is not a new concept—the river has been regularly dredged (materials removed from the riverbed to allow for smooth transportation corridors) and the sediment has been historically deposited offshore. This pilot project redirects this sediment for re-use closer to home.

In February 2023, there were 11,000 cubic metres of mostly larger-grained sand transferred from the Fraser River to the foreshore of Sturgeon Bank. This year, 4,000 cubic metres of finer-grained silt was deposited in the same locations using a 1.4-kilometre pipeline that transported the sediment from a nearby barge after it was dredged from a local marina. The total deposit of 15,000 cubic metres of sediment would fill six Olympic-sized swimming pools!

The project was featured in the Delta Optimist Nature Notes

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Nature Notes: innovative tidal marsh restoration at Sturgeon Bank

Barge, with the sediment delivery pipeline visible in the background, where sediment is held during transport from dredging to deposit on Sturgeon Bank. © Ducks Unlimited Canada

Benefits unveiled

The benefits of marsh restoration extend far beyond ecological renewal:

Re-using dredged sediments: By repurposing sediment that would otherwise be discarded, the project offers a sustainable solution for sediment management while supporting marsh recovery. This approach not only mitigates environmental impacts but also promotes the efficient utilization of resources.
Coastal flood protection: A healthy marsh serves as a natural buffer against coastal erosion and flooding, safeguarding nearby communities and infrastructure. By enhancing the resilience of the marsh ecosystem, the project contributes to the overall resilience of coastal areas.
Ecological restoration and resilience: The Sturgeon Bank marsh provides critical habitat for numerous species, including juvenile salmon and migratory birds. By restoring this vital ecosystem, the project enhances biodiversity and ecosystem health, ensuring the long-term sustainability of the region’s natural heritage.

The project was featured in Richmond News

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Second phase of Sturgeon Banks rehabilitation launches

Aerial view of the sediment delivery pipeline extending across the estuary habitat © Ducks Unlimited Canada

A vision for the future

If the pilot project is deemed successful and sediment continues to be added to the Sturgeon Bank foreshore, the project will set its sights on long-term success. Through collaboration and innovation, the aim is to scale up efforts, potentially extending the restoration model across the Fraser River Delta.

With support from diverse stakeholders and funding sources, including the British Columbia Salmon Restoration and Innovation Fund, this project stands as a testament to the power of collective action in safeguarding our natural heritage. As the marshes of Sturgeon Bank undergo a remarkable transformation, the hope is that they serve as a symbol of resilience and hope.