TULALIP, Wash. (AP) – Coho Creek stinks.
Along parts of the stream, the stench of rotting fish carcasses is overwhelming.
“The smell of success,” said Kurt Nelson, environmental division manager for the Tulalip Tribes.
Ten years ago, Coho Creek was a drab, nameless, straight-as-an-arrow drainage ditch. Today, much of it is a meandering stream filled with salmon with a name to match.
The Tulalip Tribes began working in 2000 to transform the ditch, located behind Quil Ceda Village west of I-5, into a stream to which as many as 50 coho and 1,500 chum salmon have returned in a given year.
“The numbers are varying quite a bit but they’re going up,” Nelson said.
So far the tribes have spent about $1 million on the project. The tribes have gradually upgraded the stream over the past decade by removing or improving culverts, widening the stream and changing its course, adding spawn-friendly gravel and using logs to create small ponds.
The stream runs south from around 116th Street NE and behind Quil Ceda Village, where several tributaries join it. Much of this area was leased by the tribes to the U.S. Army around World War II for munitions storage, then leased to Boeing until 2001 for engine testing.
It’s not certain where the stream originally ran, but it had been turned into a narrow ditch that flowed in a straight line due south, then due east to connect with a natural channel near 88th Street NE.
From there, the stream runs south and empties into Quil Ceda Creek near the Sno-Isle Library offices.
Over the years, 18 culverts were built into the ditch, blocking fish from traveling upstream to spawn.
After the first culvert near the south end of the stream was removed in 2000, chum salmon almost immediately began heading upstream to spawn, though without success. The creek bed still was too sandy to hold eggs.
Later, more culverts were removed, allowing both chum and coho salmon to make it farther upstream. The tribes started rebuilding the stream itself in 2007.
A trackhoe was used to carve a meandering path and fill in the old ditch, said Joe Reeves of Reeves Excavating of Quilcene, which has done most of the work for the tribes.
About 2,500 feet of new stream channel has been created in this way, with gravel added and native trees planted along the shoreline.
The original restoration effort was aimed at attracting Puget Sound coho, or silver salmon, which are listed as a “species of concern” – a species that has declined but not enough to warrant listing under the Endangered Species Act, according to the National Oceanic and Atmospheric Administration. Nelson’s goal is to have 300 to 400 coho salmon return to the stream every year to spawn.
Chum salmon have found Coho Creek to their liking as well.
“Every time we put new gravel in there, you see fish using it,” Nelson said. “That shows just how limited the spawning habitat is.”
Tribal staff are tracking the survival of the salmon eggs hatched in the stream by monitoring outgoing juvenile salmon in a smolt trap below the restoration work. The number of juvenile fish has been climbing slowly. Last spring, several thousand chum fry and coho smolts were observed leaving the restoration area, the most observed since monitoring began.
Tiny chum fry leave the stream for salt water in their first year, while coho stay in the fresh water and grow for a year before heading out. The chum fry make a perfect food for the older coho smolts, Nelson said.
Some of the old ditch still remains. The plan is to replace it with 2,500 more feet of new stream and add wetlands to offset any water runoff from further development of Quil Ceda business park.
The tribes eventually plan to develop 500 more acres of land west of Quil Ceda Village, leaving 1,000 acres nearby for environmental restoration, Tribal Chairman Mel Sheldon said.
“The rest will be preserved or restored as fish and wildlife habitat,” he said.
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