BCWF Watershed Team

The Significance of The Fraser River Estuary

Recognized as an internationally significant center of biodiversity, the Fraser River estuary is an area of ecological importance.

The Fraser River Estuary is essential for at least 102 at-risk species and functions as a key migration route and nursery for all five of B.C.’s Pacific salmon species. It’s an internationally recognized Important Bird and Biodiversity Area, hosting over 1.7 million birds yearly and supporting 260 bird species, nearly half of B.C.’s total. Additionally, it provides a habitat for a wide variety of other species that rely on its unique ecosystem.

For millennia, the Fraser River Estuary and its surrounding environment had also coexisted with and supported over 30 First Nations. However, in the last century, extensive alterations including development, agricultural expansion, widespread dredging and diking, climate change, and pollution have taken a toll on this ecosystem. These transformations have deeply impacted the once-thriving ecosystem’s ability to support diverse biodiversity, leading to uncertainties about its future health.

Restoration efforts are now crucial to address this challenge and protect the remaining natural areas.

The Current State of the Fraser River Estuary and Surrounding Ecosystems

Wetlands — An estimated 70-90% of wetland habitats have been lost surrounding the Fraser River estuary. The remaining fragments of wetlands continue to suffer from degradation by human disturbance.

Salmon Habitat — Human-made structures like dams, culverts, and floodgates have eliminated around 1727 km of linear stream salmon habitat. As a result, many salmon populations are now at historically low levels, with catches being only a fraction of what they were several decades ago.

In 2021, a concerning report by COSEWIC revealed that 76% of southern BC Chinook salmon, vital for the survival of the endangered southern resident killer whales, are in jeopardy. About 45% of these Chinook salmon are classified as endangered. The scarcity of suitable estuarine environments for salmon rearing contributes to this problem. 

Disturbingly, projections suggest that without intervention, two-thirds of the at-risk species in the estuary have less than a 50% chance of survival in the next 25 years. 

The Impact of Heavy Debris in The Fraser River Estuary

The proliferation of heavy debris in the estuary has harmed vegetation, potentially affecting its ability to perform essential tasks such as nutrient cycling, erosion prevention, and providing habitats. These ecosystem services are crucial for the overall vitality of the region.

Debris in marshes poses threats to vegetation by potentially disrupting its role in nutrient cycling, erosion control, and habitat provision, along with other ecosystem services. The presence of heavy debris can compact sediment, altering soil biochemistry and impacting the return of native vegetation while encouraging the growth of non-native species. Plastic debris, in particular, possesses smothering capabilities that can hinder primary productivity, invertebrate biomass, and nutrient exchange. As plastic breaks down, it adds to the accumulation of microplastics in the environment, the consequences of which are not yet fully understood. Furthermore, debris in marshes endangers fish and wildlife, leading to entrapment and ingestion risks that range from mortality to disruptions in biological functions such as movement and digestion.

Our Project’s Impact

Given these challenges, urgent action is needed to reverse the current trajectories and ensure the Fraser River estuary’s long-term health and sustainability. Evidence, does however, suggest that through our work, the removal of debris will have a significant positive impact on marsh habitat quality. Tidal marsh vegetation is resilient and may recover relatively quickly following debris removal!