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Pilot project protects Sturgeon Bank marsh
By Hannah Scott
Published 11:51 PST, Fri February 24, 2023
Last Updated: 11:52 PST, Fri February 24, 2023
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Richmond’s Sturgeon Bank is the site of a new pilot project aimed at protecting the crucial marsh area through sediment deposits.
The tidal marsh off the west coast of Richmond has been receding for some time, losing hundreds of metres of marsh. Investigation into the problem has increased in the last decade; senior restoration biologist Eric Balke first got involved in 2016 while working on his Master’s degree research.
“It’s really tricky to conduct science in such a dynamic place, such a variable place, and the marsh recession has occurred over such a large area and such a large period of time,” he says. “Trying to play that forensic scientist can be a bit challenging.”
The current Sturgeon Bank Sediment Enhancement Pilot Project, which is led by Ducks Unlimited Canada in partnership with several other groups, is part of a larger initiative—the Fraser River Estuary Salmon Habitat (FRESH) Restoration Project. This government-funded project, ongoing since 2021 and ending in 2024, is part of the BC Salmon Restoration and Innovation Fund. Through it, Ducks Unlimited and its partners are hoping to restore estuary tidal marsh habitat for the benefit of salmon and other fish in the Fraser River.
The sediment enhancement project is receiving additional funding from Tsawwassen First Nation and Vancouver Fraser Port Authority. Balke says there is potential for the project to scale up. Current funding allows for two years of annual sediment addition, and more funding is being sought for the future.
“We want to add sediment to an area of receded tidal marsh,” he says. “We use a technique that is trying to mimic natural sediment delivery that would have happened from the river itself. (We’re) going to take sediment that’s already being dredged from the Fraser River as part of navigation—while normally that sediment would be dumped out into the Salish Sea, instead we’re going to reuse that sediment—(and) pump it through a temporary sediment delivery pipeline into the area of receded tidal marsh.”
The sediment enhancement project addresses one possible mechanism for tidal marsh shrinkage proposed by Balke and other researchers. Other possibilities may include relative sea level rise, snow geese and Canada geese eating the marsh for large parts of the year, and increased salinity due to diverting sediment.
Restoring the tidal marsh will benefit salmon and migratory birds, as well as reducing local flooding.
“Tidal marshes support coastal flood protection and add to coastal flood defences,” says Balke. “Doing nothing potentially makes (us) even more vulnerable to coastal flooding.”
Balke calls it a “win-win-win” because dredged sediment, which would otherwise go to waste, can be reused to restore the marsh.
“We’re taking a bit of a precautionary approach, not dumping a ton of sediment out there that will be seen as mounds for years,” says Balke. “The first year, we’re targeting just under 13,000 cubic metres of sediment.”
During the initial stage, a pipeline is placed by crew members. Sediment will be pumped in over a period of four to five days. A hands-off approach, with no additional machinery digging sediment around, minimizes impacts to the environment.
“From an ecological perspective, the Fraser River Delta is a Ramsar Wetland of International Importance,” says Balke. “From a bird perspective, it’s the last stop on the Pacific flyby migratory route up to the Arctic; it’s of hemispheric importance. The Fraser Delta is the single most important location in Canada for raptors and waterfowl; from a bird perspective, this is a gem. From a fish perspective, it’s the largest salmon river in Canada and the Fraser Estuary is the biggest estuary in western Canada. Juvenile Pacific salmon can rely very heavily upon the tidal marshes of the estuary as part of a key aspect of their life cycle.”
With impending sea level rise also on the horizon, the sediment project provides an opportunity to improve areas like Sturgeon Bank; Balke is in favour of planning for the future by trying pilot projects like this one to see what is most effective.
Since the west coast of Richmond is subject to strong winds and waves, it is particularly in need of protection.
“Fish and wildlife aside, from a selfish perspective these tidal marshes are helping to protect us—if they continue to die off, that makes us more vulnerable to coastal flooding from sea level rise,” says Balke.
Individuals can help by remaining on the dyke paths and keeping their dogs out of the marshes. People can also speak to local elected officials to advocate for what Balke calls “nature-based solutions to coastal flooding.”
“I’ve had very positive reception from (Richmond) mayor and council and city staff; they’ve been supportive of this project and helpful,” he says.
People walking along the dyke will see information boards and a scannable QR code that provides more information.
“This is one project in a huge delta—it requires a village, as the metaphor goes. We’re all required for shared stewardship of this important area. When it comes to big things like sea level rise, it can feel overwhelming,” says Balke. “We don’t have to feel hopeless to these overwhelming challenges—we can chip away at it, but we do need to take action.”