Swimming Against the Current

Seattle's New Seawall Uses Technology That Could Rescue Salmon

In a time of broken international emission agreements and losing climate change battles, Seattle sets out to be the model for cities living on shorelines—one struggling salmon at a time.

By Hayat Norimine July 12, 2017 Published in the August 2017 issue of Seattle Met

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There’s a secret world under Seattle’s Elliott Bay waterfront. Pay attention and you’ll catch glimpses through the translucent glass panels that checker the sidewalk. Daylight streams onto a 7,000-foot-long corridor below, a living shoreline under the shoes of bustling tourists, and home to an icon of the Pacific Northwest: salmon.

The fish have earthquakes to thank. Or rather our vulnerability to earthquakes. After 81 years, the city’s seawall, which keeps Elliott Bay out of Elliott Ave and other downtown Seattle streets, is getting an upgrade to protect critical infrastructure from the Big One, which seismologists predict will shake the region sometime between 50 years and five minutes from now. But the new and improved, $410.2 million project serves another purpose. Seattle’s out to show that salmon and humans can coexist. 

It’s rare that a city goes out of its way to include fish in its infrastructure plans. But it’s no surprise it happened here. Eco-friendly Seattle in 2011 enacted goals to address climate change: By 2030, reduce carbon emissions 58 percent from 2008 levels; by 2050, establish zero-net greenhouse gas emissions. And with president Donald Trump pulling out of the Paris climate accord, city officials want to step up their game further to make up for efforts the country may lose on the federal level. 

Salmon migrate from the Duwamish River to the ocean. And when they arrive at Seattle’s piers, they encounter…shadows. Afraid of the dark, where they can’t see their food and larger fish lurk undetected, the salmon swim in circles. 

The shadows cast by the piers become a literal barrier between the young fish and the crustaceans they eat. Juvenile salmon are hardwired to seek shallow waters, where they take refuge from predators. And with sea levels rising, and oceans growing more acidic, protecting them has never been more challenging.

Before the city began its design plans for the new seawall in 2010, officials reached out to Jeff Cordell, a researcher at the University of Washington, who spent his career restoring aquatic ecosystems, and his life drawn to fish. He grew up fishing alongside his dad and brother on Normandy Park, south of Seattle and, in sixth grade, placed second at a science fair for a project on collecting invertebrates. 

“I’m still collecting invertebrates and putting them in formaldehyde,” he says with a laugh, surrounded by small tubes of samples in his UW office, “and getting paid for it, 50 years later.”

The first phase of the seawall, slated to finish by fall 2017, is the envy of cities around the world—Sydney, Australia, and Vancouver, BC—seeking a model for their own shoreline projects. 

Here’s how it works: The glass panels lodged into the concrete sidewalks grant young salmon natural light, inviting them into the corridor where they encounter a wall of food. The bumpy, textured vertical wall, shelved with grooves, allows ground scum and crustaceans ample surfaces on which to grow. The intertidal bench provides salmon with shallow waters, where more of their food sources thrive.

And what’s good for fish can be good for people, says Stu Munsch, whose graduate work at UW centered around the seawall project. The glass panels may just look like an aesthetic addition to the sidewalks. 

Starting next spring, Cordell and his researchers will monitor just how effective, over the next 10 years, the changes to the seawall are for fish habitat.

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When the seawall corridor is filled with water, young salmon feed off the crustaceans that grow on the ample wall surfaces.

For those who grew up in the region, the Pacific Northwest holds strong ties to the salmon that in the late 1800s were central to its growing economy. In the early twentieth century, after decades of mass commercial fishing, it became clear—the fish were in trouble. By the mid-1900s, dams were preventing salmon from moving upstream. Farming and logging reduced spawning grounds and exposed juvenile salmon to chemicals in the freshwater. Several species of salmon are now listed on the federal Endangered Species Act, including three from the Puget Sound region (chinook, bull trout, and steelhead). 

“My whole life, we grew up with this imagery of salmon, the history of salmon being out at sea, returning, the struggle to go up the river,” Cordell says. “It’s an icon for the Pacific Northwest in many ways.”

The problem goes beyond what cities can do, said Tom Bigford, policy director of the American Fisheries Society. Ocean acidification is killing shellfish and harming salmon populations. And according to researchers, sea levels in some Pacific Northwest areas are expected to rise up to four feet in the next century—another major strain on salmon. And because it’s salmon, “it really hits close to home,” Bigford says. “It’s personal, it’s regional—it’s a big, big deal.”

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