The Fraser Estuary: A Vital Linkage Across Space and Time*

The Fraser River stretches for 1,375 kilometres (the distance from Vancouver to Regina) across the province of British Columbia. Over 60% of BC residents live within the river basin, which makes up 25% of the province’s land mass. The river splits into 3 arms as it approaches Georgia Strait with the north and south arms embracing Vancouver International Airport while the main arm flows past Steveston. This stretch of the river, where fresh water meets and mingles with salt water, is known as the estuary.

Estuaries provide a rich smorgasbord of both food and habitat for a wide array of animals, birds, and plants. They are also a focal point for shipping, fishing, agriculture, and industry. Some of the world’s largest cities (London, Amsterdam, Shanghai, Buenos Aires, New York) have evolved at the mouths of the world’s mightiest rivers. As a result, human activity has a disproportionate impact on the estuaries’ wild inhabitants. We spoke with Dr. Ken Ashley, Director of BCIT’s Rivers Institute, to find out more about the Fraser estuary and its inhabitants.

The World’s Most Productive Ecosystem

“Estuaries are the world’s most productive ecosystems,” explains Ken. “They are also the most threatened ecosystem on the planet.”  As the tide rises, “a deep layer of dense saltwater slides under the less dense river water and delivers the oceans’ nutrients,” writes Dr. Colin Levings (The Soul of the Fraser). This salt wedge travels as far upriver as the Alex Fraser Bridge, a distance of 20-30 km, providing nutrients for growth to a vast expanse of water and land.

Estuaries consist of several different strata. The brackish water is a critical habitat for juvenile salmon where they spend several days adjusting to a saline environment before heading out to sea. Mudflats may appear barren, but they are anything but. A thin biofilm of algae and diatoms contains an elevated concentration of high-value Omega 3 fatty acids and is of critical importance to migratory birds such as western sandpipers and dunlins. “The mudflats are like a gas station on the Pacific flyway,” says Ken. “They’re of critical global importance.” Further inland, there are low, middle, and high marshes, each of which support different populations of plants and animals, providing vital links in direct and indirect food chains between plants, grazers, and predators.

An additional source of nutrients is provided by rotting plants and other detritus. The decaying plants support a huge number of insects and invertebrates at the base of the food web. They also play an important role in sequestering carbon as the detritus sinks and becomes part of the estuary’s sedimentary base.

For centuries, we’ve built dikes to contain the sea and protect the land. Estuarine marshes perform this function naturally, breaking the force of the waves and preventing soil erosion.

“Ecological Resilience is Finite”

Estuaries are a dynamic, ever-changing environment where small changes in water and land level and distribution can have a significant impact. “Where on a mountain, several meters can mean life or death for a species, in the Fraser delta, it’s centimetres,” writes Dan Stewart (The Soul of the Fraser). Human activity can and does negatively impact this invaluable natural resource.

Four out of five of Metro Vancouver’s wastewater treatment plants discharge directly into the estuary. None of the plants go beyond targeting biodegradable carbon, suspended solids, nitrogen and phosphorus, and control of fecal coliform bacteria (the Iona plant, which treats the waste from 600,000 Vancouver residents, remains a primary treatment facility with no plans to upgrade before 2030). They do nothing to address bioplastics or legacy chemicals. The long-held theory that ocean water would dilute toxic waste is false. Instead, the chemicals become concentrated as they make their way up the aquatic food chain.

Vancouver International Airport is built on the estuary as are the Tsawwassen Ferry Terminal, the Roberts Bank container terminal, export terminals for US thermal coal and LNG, and a YVR jet fuel terminal. Five major bridges as well as the Massey tunnel cross the estuary. The riverbanks are lined with industrial plants. The overall result has been a major increase in pollution and a significant decrease in salt marshes and mudflats. In addition, ever-growing numbers of snow geese and Canada geese are uprooting the marsh grasses causing the sea levels to rise and increasing the salinity so that grass no longer grows in these areas. This is a huge loss to wildlife but also to human residents as the marshes are no longer available to buffer the force of the ocean and combat the rising sea levels.

As ships increase in size, frequent dredging of the main channel to allow the ships to pass buries the all-important biofilm and lowers the marshes, taking away both food and habitat.

Over the years, 5 jetties up to 9 km long have been built to channel the sediment and to perform a variety of industrial functions (access to the Tsawwassen ferry terminal, train tracks to the Roberts Bank Port Terminal, a deep ocean outlet for the Iona sewage treatment plant), fragmenting the estuarine habitat and creating a significant barrier to movement into and around the estuary. Fish and other aquatic creatures must make long detours around the jetties, placing them at greater risk from predators. Birds are reluctant to fly over heavily industrialized areas. Water levels and salinity are affected, and sediment no longer accumulates, stopping shore lines from adapting to sea level rise.

Who Governs?

Estuaries are composed of land and water, both fresh and salt, falling between the cracks when it comes to environmental oversight and protection. In the ‘70s and ‘80s, enlightened governments prepared a series of studies on the Fraser estuary and established the Fraser River Estuary Management Program. The plan created 3 zones: one which could be built on, one which could be built on but required compensation, and a third where no development was permitted. Development proposals were evaluated by a cross-agency, cross-disciplinary panel. Applicants could no longer play one agency off against another and proposals received a technical, governance, and policy review. The Conservative Harper government ended the funding, and oversight is now provided by the Port of Vancouver with an obvious bias towards increasing shipping and industrial facilities. A second Roberts Bank Terminal is currently under consideration despite a negative environmental review.

Signs of Hope

A new generation of scientists and environmentalists are bringing increased attention to the plight of the Fraser estuary. There has been strong advocacy against a second Roberts Bank Terminal. Raincoast Conservation Foundation and Tsawwassen First Nation have created a 300-metre breach in the North Arm jetty, opening a path for salmon to develop in the tidal marshes before being pushed out to sea and creating more natural flows of sediment and saline to and from the estuary. Experiments are underway to create living dikes in Boundary Bay.

Rivers Institute

BCIT’s Rivers Institute, under the direction of Dr. Ken Ashley, is playing an increasingly important role in educating and advocating on behalf of rivers. The Institute, through BCIT’s Ecological Restoration Program, offers undergraduate and graduate degrees in ecological restoration, provides guidance for community-based restoration initiatives, and mentors the next generation of ecological restoration professionals. The Institute has prepared a series of 3 books and documentaries about the Fraser River as the basis for wide-reaching public education programs. The Institute has been funded since 2009 by philanthropist Rudy North.

Further Information

Rivers Institute, BCIT

The Heart of the Fraser (book & documentary)

The Soul of the Fraser (book & documentary)

Against Port Expansion in the Fraser Estuary, BC

How Scientists are Giving Fraser River Salmon a Fresh Chance, The Narwhal

How a Salt Marsh Could Be a Secret Weapon Against Sea Level Rise in BC’s Fraser Delta, The Narwhal

* with thanks to Misty MacDuffee, Raincoast Conservation Foundation, for her eloquent description of the Fraser estuary in The Soul of the Fraser

Photo credit: Rivers Institute

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