Salmon are critical to every aspect of the ecosystem in the Pacific Northwest. From the small bugs that feed on their decaying carcasses, to the birds and scavengers that take advantage of that rich source of protein, to the very trees that make up our forests and greenery, many species rely on salmon to bring those nutrients from the ocean back to the stream environment.
Here in Gig Harbor, the salmon life cycle begins in Crescent and Donkey Creeks. Salmon return to these creeks year after year to lay an average of 3,000 eggs the size of peas in shallow depressions, called redds, in the streambed gravel.
Once they hatch, the baby salmon bury their heads into the gravel to keep from getting washed downstream. From there, they absorb the yolk sac, their nutritious first fuel, and then begin their life cycle out in the open as a swimming fish.
After maturing, they will travel out of the creek and into the estuary where they begin acclimating to the salt water. From the brackish water of Puget Sound, the salmon continue their journey to the Pacific Ocean; navigating thousands of miles from their home creek to find food and accumulate mass.
Donkey Creek itself has quite the history. A trestle bridge was built across the creek in the 1880’s to connect early downtown Gig Harbor with the Finholm District. In 1949 this bridge was torn down so that North Harborview Drive could be built. At this time, a 36-inch culvert was laid to re-route Donkey Creek, before it was buried under the new roadway. This drastically changed the dynamic of the creek. Most of it was no longer visible to the public, nor did it receive tidal flow from Gig Harbor Bay.
The creek was restored in early 2014 as part of the City of Gig Harbor’s Donkey Creek Restoration and Transportation Improvement Project. The roadway and culvert were replaced with a bridge that “daylights” the creek, restoring traditional water flow into Austin Estuary for the first time in 65 years. The restoration was a success for our local watershed and salmon who instinctively continue to return and spawn in the creek.
However, a second culvert still remains underneath Harborview Drive, at the upper stream of Donkey Creek, and continues to pose a significant barrier to salmon and other species of fish that navigate the creek.
Culverts are meant to allow the passage of water from one side of a road to the other. When road construction alters or eliminates a stream, the water flow is often channeled through these structures, made of concrete, metal, or plastic. And this re-routing of water would be a good solution — except culverts change the dynamic of a creek’s water flow and often pose a barrier for fish passage.
Donkey Creek’s second culvert was assessed by the Washington Department of Fish and Wildlife in April 2013. Their data classifies the culvert, as well as two more culverts on private property in an upper tributary of Donkey Creek, as a “total fish passage blockage.” In comparison, the culvert at Crescent Creek is classified as a “barrier” with “unknown percent passage” for fish.
This obstacle poses two main issues for salmon: after strenuously jumping up and into the culvert, they must then swim the entire length without a place to rest. Depending on water flow, the vertical distance from the creek to the culvert can be significant. The process is difficult and tiring; many salmon expend energy making multiple attempts, are washed out from the culvert by the fast-moving water flow, or give up altogether and spawn in the lower portion of Donkey Creek. When this happens, their eggs have a lower survival rate; the streambed gravel isn’t suitable for redds and the eggs are at a higher risk of disturbance from water turbulence and predation.
While salmon return to the creek year after year, their spawning success, and thus the number of returning salmon, would increase without an upper-stream impediment.
Our community is proud of the extensive restoration of Donkey Creek and the next step in this success story should include removing the second culvert for natural fish recovery. Not only do Chum salmon return year after year, but Fish and Wildlife reports that the stream is also traversed by Coho salmon, as well as cutthroat and steelhead trout.
The City of Gig Harbor is currently researching grant and funding opportunities to address removal of the second culvert. Funding for the removal could be secured from grants dedicated to conserving wildlife habitat and would encourage the viewing and education of spawning salmon every fall.
The trail at Donkey Creek Park is a beautiful area to view spawning salmon, and we are only a few weeks away from the return of chum salmon to Gig Harbor in mid-November. Let’s continue to support their arduous journey and recovery in our own backyard.
Carly Vester, a Gig Harbor resident and member of Harbor WildWatch, writes monthly for The Gateway about the environment. Reach her at firstname.lastname@example.org