Research to resilience: How data can help transform our landscapes for the better

Research leads to recommendations  

This research resulted in a comprehensive report, originally published in 2022, which has since been adapted and published in the peer-reviewed journal, Wetlands. The article, “Factors Influencing the Resilience of Created Tidal Marshes in the Fraser River Estuary, British Columbia,” was published on May 1, 2024 and made publicly available through a contribution from the Nature Force. It reveals common factors influencing the fate of tidal marsh projects and provides recommendations that guide future restoration efforts in the FRE and beyond.  

“Research like this provides so much opportunity for future planning, and tests whether projects are providing the benefits they were designed for,” comments James Paterson, PhD, a research scientist with Ducks Unlimited Canada’s Institute for Wetland and Waterfowl Research. Paterson is co-author of the recent journal article.  

Indeed, the research revealed that marsh recession, among other challenges, was a major factor in the declining health of the FRE.  

Four major considerations in marsh restoration:

Marsh Recession

Over half of created marshes experienced recession, where planted, vegetated areas turned into bare mudflats. Erosion from boat wakes, plant consumption by Canada geese, altered sediment processes —often from human intervention— and sea-level rise emerged as potential drivers, emphasizing the need for multifaceted mitigation strategies. Notably, project age did not appear to be a factor, meaning well-designed and implemented restoration projects could last for decades. Conversely, some recently constructed projects have already experienced substantial recession, suggesting innovation is still required to ensure the longevity of projects.

Elevation and Sea-level Rise

Site elevation emerged as a significant predictor of marsh recession, with lower elevations more at risk. This likely reflects the sensitivity of these areas to disturbance and environmental change. Coastal squeeze looms large, with rising sea levels potentially exacerbating the challenges faced by native marsh communities.

Invasive Species

The encroachment of invasive species poses an ongoing threat to both constructed and natural marsh ecosystems, with implications for biodiversity and habitat integrity. Managing invasive species requires a nuanced understanding of their ecology and interactions with native plants.

Site Design and Protective Infrastructure

The design of constructed marshes, including their elevation, location in the estuary, and their connectivity to the river, emerged as determinants of resilience. Some designs had better outcomes, underscoring the importance of thoughtful planning and consideration of trade-offs during the site selection and design of a project. 

Recommendations lead to on-the-ground solutions  

These factors are not entirely insurmountable. In fact, observations made during the study were among the driving factors that influenced multiple restoration projects that have already begun in the FRE. Projects like the Sturgeon Bank Sediment Enhancement Pilot Project directly tackle the challenge of tidal marsh recession by using reclaimed sediment from the Fraser River and redistributing it over the nearby receding tidal marsh.  

“Our extensive work in the Fraser River Estuary reflects our commitment to this region. With the guidance of research like this, we are making strides to safeguard vital habitats here,” says Eric Balke, DUC senior restoration biologist and co-lead for the on-the-ground component and authorship of the report and journal article. 

Elsewhere, projects like the Frenchies Island Invasive Cattail Management Project, and the internationally supported Spartina Program —targeting the eradication of an invasive cordgrass now found in the FRE— tackle the challenges posed by altered local biodiversity. 

Resilience for the future

Daniel Stewart, wetland biologist and ecologist of Asarum Ecological Consulting and lead author of the journal article and report remarks, “Sometimes the first step to improvement is to admit we can do things better. We see in the data that these tidal marshes are changing before our eyes, and working with Ducks Unlimited Canada brings attention to the areas where we can have the most positive impact. It’s an empowering thing; seeing data turn into recommendations, and seeing recommendations turn into real-world restoration efforts based on innovative solutions.” 

Indeed, research like this and the collective efforts of researchers, practitioners, funders and stakeholders give hope for resilience both now and in the future.