Photo depicting a female-presenting Puget Soundkeeper volunteer dissecting a dead salmon beside the Longfellow Creek.

In the Duwamish Watershed, Communities Respond as Coho Salmon Face a New Threat

by Tushar Khurana


Every year, salmon journey from the open waters of the North Pacific, pass through estuaries along the coast, and swim upriver to spawn in the freshwater streams and creeks in which they were born. Yet across the western coast of North America, coho salmon are dying in large numbers as they return to urban watersheds. In West Seattle, a team of citizen scientists are surveying salmon to understand how many are affected.

Since 2015, small teams of volunteers have gone out every day in the fall to document returning salmon along a quarter mile stretch of Longfellow Creek.

The study, which is coordinated by the environmental nonprofit Puget Soundkeeper Alliance, is modeled after similar publicly funded studies run by the City of Seattle and the National Oceanic and Atmospheric Administration between 1999 and 2005. As Puget Soundkeeper Alliance’s Gillian Flippo explains, “The salmon are uniquely affected by the stormwater … causing them to die before they spawn.” It’s a phenomenon that researchers are calling “pre-spawn mortality” or “Urban Runoff Mortality Syndrome.” All told, the surveys show that each year between 50% and 80% of returning coho are dying from exposure to urban waters.

Imagined differently, after surviving for nearly 16 months in freshwater streams and another 16–18 months in the open ocean, and having traveled as far as the Gulf of Alaska and back, over half the coho salmon that return die within hours of contact with these polluted watersheds and before they get a chance to lay their eggs.

Despite grim results, this work and complementary efforts by volunteer and professional scientists across Puget Sound have begun to bear fruit. While it was first observed in the 1980s, a team of University of Washington and Washington State University researchers recently discovered that a single chemical, 6PPD-quinone, seems to be the cause of this alarming death rate. A by-product of a chemical commonly found in car tires, 6PPD-quinone enters the blood and then the brain of coho salmon. They soon lose their sense of direction, swim to the surface, spasm, and die within hours.

How do you solve a problem caused by a chemical found in nearly every car on the road that can kill over half the returning coho salmon each year? Green stormwater infrastructure (GSI) — or systems of plants and soil that filter stormwater along roads and waterways — could be part of the answer. Gillian says that “it’s been shown that this bioinfiltration prevents lethal stormwater impacts.” She adds that we could “[implement] this infrastructure right now while working on larger scale solutions to lessen this pollution in the first place.”

Of course building out this infrastructure at scale would cost an enormous amount of money. In the nearby Barton neighborhood, a 15-block GSI project cost over $17 million to construct. The longer-term solution of reducing cars on the road would cut this pollution at its source and reduce air pollution, traffic deaths, and climate-changing greenhouse gas emissions — but that’s no easy task, either. In 2018 The Seattle Times estimated that there were 457,000 cars owned by Seattle residents and that 81% of city households owned at least one car.

Just as importantly, while the discovery of 6PPD-quinone and this level of mortality may be unprecedented, salmon populations face no shortage of threats. Scientists generally agree that salmon populations peaked and then began a steady decline in rivers across the Pacific Northwest between 1882 and 1915. The people- and place-based history of salmon decline and protection over the century offers useful context for thinking through the issue today.

Photo depicting a salmon fish swimming along a creek.
Salmon in Longfellow Creek. Photo courtesy of Puget Soundkeepers.

Salmon and the Duwamish

Longfellow Creek runs for 3.5 miles through what are now the Delridge and Roxhill neighborhoods of West Seattle before joining the Duwamish River close to its mouth at Elliott Bay. A few blocks to the east, Puget Creek flows down along the ridge and into the river near Kellogg Island, past the present day Duwamish Longhouse and Cultural Center. Herring’s House, the historical site of a Duwamish settlement made up of several longhouses, is located nearby. Ken Workman, former Duwamish Tribal Council member, Duwamish Tribal Services president, and direct descendant of Chief Si’ahl (also known as Seeathl, Sealth, or Seattle, the city’s namesake), grew up in between these two creeks. “The Duwamish people,” as Workman described, “have been living and playing in that area for thousands of years. The area near Longfellow Creek would have been a good place for a longhouse and a source of salmon.”

Indeed the remains of an old fishing campsite along Longfellow Creek was dated back to the 14th century. As further evidence that it was a fishery, an Indigenous name for the creek is t?áwi (pronounced t-AH-wee), which, in the Lushootseed language spoken by many southern Salish tribes, is the name for a type of small fish.

B.J. Cummings, author of the book The River That Made Seattle, adds that in addition to salmon, clams, crabs, and seaweed, “a wide range of traditional foods, clothing, household, building, and ceremonial supplies were harvested from the [Duwamish] watershed, including cedar, wapatos (a water potato), plant tubers, game meat, birds, etc.” This abundance has been managed and stewarded by the Indigenous tribes since time immemorial. And the river continues to sustain human life.

On most days you can find someone with a fishing pole — or a handful of people for that matter — on the fishing dock by Southwest Spokane Street, which crosses over the Duwamish River just under the West Seattle Bridge. In addition to tribal members, over 20 ethnic groups fish in the Duwamish River for sustenance. The river is so polluted, though, that resident fish are unsafe to eat. Salmon, like the coho that spawn in Longfellow Creek, are the safest fish to catch and eat because they spend very short periods of time in the river.

In 1855 the Treaty of Point Elliott ceded the land that Seattle sits on today and guaranteed that the Duwamish, Suquamish, Muckleshoot, and other signatories could fish in their “usual and accustomed grounds.” Similar treaties ceded 64 million acres of land across much of Washington, Oregon, Idaho, and Montana in exchange for small reservations and the right to fish in traditional grounds. But this right was soon under attack. The Northwest Indian Fisheries Commission (NWIFC), an inter-tribal organization formed to support the 20 recognized western Washington treaty tribes, reports that salmon populations faced threats from habitat destruction, the removal of forest cover, the building of dams and barriers such as tide gates and culverts, and commercial fishing.

Tribes across the Northwest fought to protect salmon runs and their treaty right to fish as soon as this decline began. The first legal challenge to reach the U.S. Supreme Court was in 1905. Perhaps the best known political struggle took place in the 1960s and ’70s, when Native activists throughout the state engaged in the “Fish Wars” to protect their right to fish. Native fishers in Seattle and throughout Puget Sound participated in “fish-ins,” an analog to the civil rights era sit-ins that were happening at the time.

In a series of resulting court cases — and as recently as 2018 — the U.S. Supreme Court acknowledged that the United States has a treaty responsibility to protect salmon habitat and ensure the continued health of salmon fisheries. Yet the NWIFC concludes in a 2011 report that while the “tribes are doing their share to promote recovery” the “federal government is not fully implementing its obligation to protect treaty rights.”

Back in Seattle, one of the first ordinances passed after the city’s incorporation in 1865 decreed that “no Indian or Indians shall be permitted to reside … in the town of Seattle.” The Duwamish tribe has faced an onslaught of attempts to remove them from the city and was denied federal recognition. In spite of this history, the tribe continues to protect and steward the watershed. In the 1980s and ’90s, tribal members founded the Green-Duwamish Watershed Alliance and worked with local environmentalists to daylight Hamm Creek by breaking open the underground pipeline it was channeled through and restoring its streambanks. The project was completed in the year 2000 and made Hamm Creek and Longfellow Creek the only two salmon spawning creeks entering the Duwamish River.

In 2001, tribal members also partnered with local environmental organizations to form the Duwamish River Cleanup Coalition (DRCC) to supervise the process of cleaning the bottom of the Duwamish River, which has been made toxic by a century of industrial waste. The DRCC has coordinated unprecedented levels of education and community engagement with the cleanup process.

In a place as complex as the Duwamish River Valley, community groups understand that the fight to protect salmon is inseparable from this local and regional history of colonization and Indigenous resistance, just as it intersects with the very palpable forces of immigration, development, gentrification, and, of course, global patterns of climate change and environmental contamination.

Photo depicting a female-presenting Puget Soundkeeper volunteer dissecting a dead salmon beside the Longfellow Creek.
A Puget Soundkeeper volunteer checks a dead salmon for pre-spawn mortality at Longfellow Creek. Photo courtesy of Puget Soundkeepers.

Intersections Along the River

On a wet Friday in November, the Emerald joined a crew of volunteers conducting a survey along Longfellow Creek near Dragonfly Pavilion in Delridge. The creek’s path has been extensively modified. Beginning just downstream of where we were, it is channeled into a half-mile-long underground pipeline before opening into the Duwamish River through a grated outlet. Any salmon that we would see had to swim through this daunting passageway. Yet despite these confinements, the creek still hosts a surprising amount of life. We startled the resident blue heron on our way to the stream, passed an overflowing beaver dam and pond, and spotted a number of chewed logs, telltale signs of more riverine construction in the works. The same kind of uncanny resilience is matched by the human communities that live, work, and sustain themselves along the watershed and who continue to protect the area.

A few blocks north, at 23rd Avenue Southwest and Southwest Findlay Street, the Delridge Neighborhood Development Association (DNDA) has led a project to improve water quality in Longfellow Creek by restoring a wetland at the site of an old electrical substation previously operated by Seattle City Light. Not only does the wetland solve a local flooding issue, filter water, and protect salmon, but it creates outdoor green space for the underserved and historically redlined Roxhill-Delridge community. Bri Castilleja, who works as an environmental educator with DNDA, serves on Seattle’s environmental justice committee, and is a member of the Samish Tribe, uses this wetland space to run youth programs and community workshops for neighborhood residents. Through classes on environmental justice and native plants, she works to highlight how Black and Indigenous knowledge frames connections to land and liberation.

DRCC remains perhaps the most iconic organization working to restore the Duwamish River. In November, the organization celebrated its 20th anniversary and changed its name to Duwamish River Community Coalition to reflect its expanded efforts in South Park’s largely immigrant and Latino community. Recognizing that residents need jobs and housing along with clean water, DRCC runs a youth leadership program and works to develop and preserve affordable housing in the neighborhood by participating in the Duwamish Valley Affordable Housing Coalition in addition to its technical advisory and community engagement efforts. During the pandemic, it shifted operations to deliver nearly 5,000 boxes of food and distribute rental assistance money.

Organizations like the DRCC and DNDA are forging models for restoring the watershed by engaging with a spectrum of community issues. As Duwamish Alive Coalition Director Sharon Leishman explains, these organizations are “at the center of the [local] web of life and focus on housing issues, community and environmental issues, educational and cultural issues … they are very holistic and that is what helps move the dial.”

Experts agree that true environmental justice requires meeting the community where it is at and recognizing that issues intersect. By all accounts, efforts to remove 6PPD-quinone and restore the waterways will require this type of empowerment and a massive mobilization of the communities that depend on the watershed and that have constantly fought to protect it.


Tushar Khurana (he/him) lives, writes, and organizes in South Seattle. He has a background in climate science, environmental policy, and clean energy.

📸 Featured Image: A Puget Soundkeeper volunteer checks a dead salmon for pre-spawn mortality at Longfellow Creek. Photo courtesy of Puget Soundkeepers.

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