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Bringing Salmon Back to the City

Joshua McNichols
08/17/2009

To a salmon, big cities make for poor habitat. Not much fish food grows on a bare concrete bulkhead. Now some scientists hope to change that. They're looking at new ways for salmon to live in the city, or at least find some food. The experiments come at a time when communities throughout the Northwest are rethinking the ecology of urban shorelines.

TRANSCRIPT

Downtown Seattle butts right up against the waters of Puget Sound. There used to be a beach here. Now, that beach lies buried beneath roads, sewers, buildings, and train tracks. A massive concrete sea wall prevents this tangle of infrastructure from sliding into Puget Sound.

Just below the sea wall, a pair of University of Washington scientists swim quietly through the water. They invite me to join them.

Reporter: "So did you see any fish down there?"

Toft: "Yeah, there's a school of about 20 Chinook right down in front of me out there."

These are juvenile salmon, no bigger than your hand. They probably came from the polluted Duwamish River, after hatching upstream. They're not ready for deeper water yet. So like a human teenager, they hang out downtown.

Scientist Jason Toft and his crew collect the salmon in nets and drop them in a bucket of sea water.They want to see what the fish are eating. Because Chinook salmon are endangered, these fish get the royal treatment. Instead of slicing open the fish, Toft flushes out their stomachs with a plastic syringe. He catches their breakfast on a small metal screen.

Toft: "I've got another wild Chinook coming up here. Well, I can see he's been eating a lot of amphipods. So those are those small shrimp–like crustaceans."

Reporter: "Those amphipods, they don't even look like living creatures. They look like seeds or something."

Toft: "Yeah, they're pretty small. There's all sorts of small life out here that small fish need to feed on to grow into big fish."

There's not much for fish to eat in downtown Seattle. They find a lot of their food in the thin layer of slime that grows on the concrete sea wall. These scientists figure if they can roughen the sea wall surface, add some complexity, they can dramatically increase the fish food that grows here. So the city let the team bolt heavily textured concrete panels to the existing sea wall. Scientist Maureen Goff has been monitoring these panels for more than a year. In that time, she's seen them develop a complex ecosystem of their own.

Goff: "That's part of the advantage of having the shade and the crevices, things that can retain water and detritus. All of these things help these organisms survive the low tides."

Washington's Department of Ecology likes the concrete habitat panels a lot. Spokesperson Peter Skowlund says this research could set a new standard for how existing sea walls are repaired or rebuilt throughout the state.

Skowlund: "That's the restoration kind of thing that we'd like to see promoted. The study is not completed yet, it's too early to get any real findings out of it, but it's definitely one that we are following."

Much of the region's salmon recovery happens in rural areas, far away from the city. But you can't neglect habitat in urban centers according to Jim Lichatowich. He's an Oregon biologist and writer. He says salmon must pass through a chain of habitats to complete their life cycle.

Lichatowich: "If you have three of those habitats that are degraded, and if through heroic efforts you fix two of those links, the chain's still broken. And it's really an important metaphor because it helps explain how we could spend so much money on salmon recovery efforts and get so little out of it."

So urban areas are still on the hook. But there are other, lower–tech ways of improving urban environments. How about native plants? That's what Portland's mayor Sam Adams wants to put along the city's stretch of the Willamette River.

It's where Matt Prue runs the CertainTEED roofing products plant. Forklifts zip back and forth across the asphalt yard. At the back of his property, a steep path of loose rock leads down to the river. He shows me some trees he planted, just like Portland's mayor wants. Prue likes the idea that fish can be attracted to dense, industrial shorelines simply by planting some shrubs. But he worries about giving up too much.

Prue: "Not even just the large businesses like ourselves, but there's a lot of small businesses that bought property. And I heard from one gentleman who said 'I just bought this property with the idea of building my business. And now I'm worried that these restrictions might keep me from doing any business at all.'"

Prue says he's optimistic that industry and nature can work together. Even downtown. It's just a question of cost.

Joshua McNichols, KUOW News.

© Copyright 2009, KUOW

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