Below, I highlight my experience monitoring and removing knotweed along the Skagit River based on field notes collected during my week there.
It's a crisp fall morning on the Skagit River—the sky is clear and the river is calm. Today we are floating down the river to survey and treat knotweed (Polygonum spp.) on the banks. As we paddle down this beautiful river, it's hard to imagine that an invasive species —knotweed— is currently threatening the delicate balance of this riparian ecosystem.
Rafting the Skagit River
Our river guide, Shane of Chinook Expeditions, expertly navigates us through narrow channels, constantly reading the waves. He knows exactly when to paddle or rest and let the current carry us.
The Skagit River stretches almost 160 miles long, beginning in southwestern British Columbia, carving through western Washington and emptying into Puget Sound. According to the National Wild and Scenic Rivers System, the Skagit is "the largest and most biologically important river" that flows into Puget Sound. It gets its turquoise-emerald color from the hundreds of mountain and glacier streams flowing into it, carrying finely ground rock particles and sediment that dramatically alter the color of the river.
Whose Land Are We On?
Out here and anywhere in the Pacific Northwest, we are on lands traditionally inhabited by Coast Salish-speaking tribes. The Coast Salish people have lived in connection with these lands and waters for over 10,000 years.
This week, we are floating between the territories of the Sauk-Suiattle Indian Tribe and the Upper Skagit Indian Tribe. Restoring these riverbanks feels like a critical step towards healing the relationships our European ancestors harmed through colonization.
Invasive Knotweed in the PNW
Knotweed was originally introduced to the PNW as an ornamental. Since knotweed’s introduction, it has thrived here, with Bohemian, Giant, and Japanese species aggressively spreading through roots and stem cuttings, threatening riparian ecosystems. If left untreated, it will continue to disrupt the riparian ecosystem, overtaking native flora.
Knotweed Project Overview
Our team has monitored and managed knotweed along the Skagit River for the past few weeks. Today, we're looking for the knotweed patch we left off on yesterday. When we get to the spot along the river bank, we jump out, and one of us surveys while the other treats the knotweed with imazapyr, an aquatic-safe herbicide applied to the foliage.
This project, initiated by the Nature Conservancy and now led by the Skagit Fisheries Enhancement Program and the Sauk-Suiattle Indian Tribe, has been ongoing for over two decades. For the past two years, the Sauk-Suiattle Tribe has hired Habitat Restoration Specialists to help control and monitor knotweed along the river.
Each year, the project starts at the headwaters and progresses downstream. Today, we've officially gone further down the river than this project has ever been - this means our efforts are working!
Next Steps
Due to decades of multi-agency collaboration, we are slowly eradicating knotweed along the Skagit and Sauk Rivers. The success of this project highlights the importance of collaboration and perseverance when it comes to ecological restoration. I am grateful to have been a part of this project this year to float, monitor, and restore the Skagit River, and I look forward to our team getting out there again next year.
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