After three years of work, the Squaxin Island Tribe and the Mason Conservation District, have controlled the spread of salmon-killing knotweed in the Skookum Creek watershed. “This is a huge step forward,” said Andy Whitener, natural resource director for the tribe. “This shows that through consistent effort, monitoring and cooperation, we can tackle persistently troubling natural resources issues.”
Invasive plants like blackberries, knotweed and reed canary grass out-compete native plants that provide better habitat for fish and wildlife. “A stream might look healthy, surrounded by plenty of plants, and appearing undeveloped, but that doesn’t mean it’s providing good fish habitat,” said Sarah Zaniewski, habitat biologist for the tribe. “If the plants aren’t shading the creek or giving fish the nutrients they need, they’re providing little benefit to fish.”
Staff from the conservation district sprayed knotweed plants or, at the request of property owners, swabbed leaves of the plants by hand. “Every year we saw progress, fewer and fewer plants came back during the growing season,” Zaniewski said.
Not only did the total acreage of the knotweed infestation go down each year, but the density of the plants also plummeted. “Because we were consistent and tracked our work, we were able to target our efforts to places we know were infested,” she said.
The tribe tracked the removal by using global positioning system technology. “The first step to controlling the spread of invasive plants was to understand how far and how fast they’ve spread,” Zaniewski said. “Also, because we accurately tracked the invasive plant populations over time, we weren’t grappling in the dark with how well our removal efforts were going.”
The knotweed removal dovetails with restoration work the tribe recently completed on Skookum Creek. The tribe has built several logjams that provide essential habitat to juvenile and adult salmon, supplemented spawning gravel, and restored several acres of streamside forest.
“The closer we can track salmon habitat, the better choices we can make restoring and protecting our salmon runs,” Whitener said.
For more information, contact: Sarah Zaniewski, habitat biologost, Squaxin Island Tribe, (360) 432-3818. Emmett O’Connell, information officer, NWIFC, (360) 432-3804, [email protected]