The Lower Elwha Klallam Tribe is watching five years of work pay off as coho salmon return to the Elwha watershed after the removal of two dams and extensive restoration work.
Since 2011, the tribe, state Department of Fish and Wildlife, Olympic National Park (ONP) and crews from Washington Conservation Corps have transported adult coho salmon into the Elwha River and its tributaries in an effort to accelerate natural recolonization above the formerly impassible Elwha and Glines Canyon dams.
The 635 fish that were transported this year were surplus from the tribe’s House of Salmon Hatchery and state hatchery on the Elwha River. Visible tags were implanted in all the transplanted fish so spawning ground surveyors could identify the origin of coho during surveys. A small percentage of coho were also fitted with radio tags to track migration patterns. Some chum salmon were transferred as well.
“Moving fish upstream has been helping with recolonization during restoration and we’re seeing the results now,” said Mike McHenry, the tribe’s habitat program manager.
“One of the tributaries, Indian Creek, is pretty much self-sustaining now and is a natural coho factory. The creek’s good habitat has led to fish spawning and successfully producing smolts,” he added. “From our first outplants of adults in 2011, Indian Creek has produced as many as 8,000 to 32,000 coho smolts. That is a rapid and significant response.”
Indian Creek flows between the sites of the old Elwha and Glines Canyon dams, built in the early 20th century with no fish ladders to enable salmon passage. For more than 100 years, fish were unable to move more than five miles up the river.
Dam removal, which was completed between 2011 and 2014, has opened up an additional 40 miles of mainstem spawning and rearing habitat. It is expected that coho salmon will colonize the majority of that habitat, mostly within the park.
In 2016, relocations have been focused upstream of the old Elwha dam site, including in Madison, Sanders and Griff creeks. Additional releases were made just below Glines Canyon. Subsequent spawning ground surveys have shown both tagged and untagged coho spawning in or near all the release sites. Additionally, park crews have observed coho spawning in Boulder Creek, representing the first documented occurrence of coho salmon spawning above the former Glines Canyon Dam site.
“Due to the challenging survey conditions we typically encounter this time of year, it’s difficult to observe fish spawning, let alone successful fish passage,” said Heidi Hugunin, the park’s Elwha fisheries technician. “Upon seeing both tagged and untagged coho in Boulder Creek this fall, as well as detecting one radio-tagged coho in the former Mills area, we know that these fish have successfully migrated upriver through Glines Canyon.
“Furthermore, the untagged coho have presumably migrated from the mouth of the Elwha River to Boulder Creek on their own volition. The natural recolonization of coho salmon is beginning in the upper watershed.”