In Autumn spawning Salmon return to Seattle’s Carkeek Park usually right around Thanksgiving. Probably Chum, but could be Coho. Let us know if you can tell what’s what.
It may seem odd that we’re writing about a fish run here, but the reality is these wild fish are returning to a small creek that isn’t far from many gardens. The Carkeek forested ravine drops off just below a number of surrounding developed neighborhoods where homeowners garden. This means the stream is fed by several tiny tributaries that run downhill from residential gardens right into the pools where the salmon lay their eggs each fall.
Any lawn killers, fertilizers or other gunk has the potential to pollute this carefully restored area where salmon have spawned since before any homes cluttered the ridge above them. It’s true that any toxins are filtered through the forest above, traveling through thickets of native trees, ferns, shrubs, and perennials. But, the potential for trouble is still there.
Too any invasive species plants can readily invade this wildlife refuge. As I watched these amazing, powerful, exhausted creatures struggle upstream to what may have been their beginning point in life and is quite likely the place they will die, I was reminded of a seminar I attended on noxious weeds. In that class, the speakers taught us about two invasive weeds that are problems for streams and steam life.
The beautiful, fragrant, pollinator feeding Butterfly Bush was one. A big problem with this plant, according to the noxious weed specialist, is its tendency to self-seed into native streams, diverting them in off-beat directions.
Obnoxious Knotweed, which honeybees also hit hard in late summer, also got a mention for its tendency to not only take over streams and divert them, but also for its ability to take up needed nutrients without giving them back into the stream. Native plants, on the other hand, may take up nutrients, but as they drop leaves and interact with the earth around them, they give back nutrients that play into the cycle of life upon which the salmon rely.
While I watched the salmon flipping about, circling in deeper pools, and rotting on decomposing logs and boulders along the shore, I observed the surrounding flora. In this carefully restored area not a Buddleia or Polygonum were in view. Rather, the stream was littered with the recently fallen leaves of Big Leaf Maple, speckled with detritus from Salmonberry and Twig Dogwood, and decorated with the evergreen fronds of our native Sword Fern. It was an idyllic visual that I hope will continue for longer than my own brief lifespan.