Greater numbers of winter steelhead have been making their way beyond where the former Elwha and Glines Canyon dams used to sit in the Elwha River for more than 100 years.
The Lower Elwha Klallam Tribe, using sonar technology, has estimated that nearly 2,300 adult winter steelhead returned to the river in 2021, an increase of roughly 300 from the previous year. This is the largest amount since monitoring started in 2013.
Visual surveys of redds (salmon egg nests) tell scientists what areas salmon are using in the watershed. In 2020, 153 redds were counted, most of them between the two former dam sites. Additional redds were found above Glines Canyon, about 13 miles from the mouth. In 2021, 197 redds were observed.
The tribe, in partnership with Trout Unlimited, Olympic National Park, National Oceanic and Atmospheric Administration, and private contractors, recently released the results of their 2020 and 2021 winter steelhead spawner surveys and sonar monitoring data.
While the number of redds found in between the two former dam sites were low compared to previous years, the number of redds found above the former Glines Canyon dam area was high, suggesting that fish are continuing to recolonize the upper watershed habitats, said Mike McHenry, the tribe’s habitat program manager.
The area just below and beyond Glines Canyon is within Olympic National Park and preserved from any development, lending the area to pristine salmon habitat.
The distribution of redds throughout the watershed also has increased. This is a positive sign for recolonization, McHenry said, because spawning winter steelhead are spreading out in the watershed and will likely continue as the river restoration process continues. However, scientists suggested expanding survey efforts beyond the middle and upper areas of the mainstem to learn more about the distribution of the redds.
Since 2011, the tribe and partners have been documenting annually where steelhead are spawning in the river between February and July, counting redds by hiking up the Elwha River from the mouth to just beyond the former Glines Canyon dam site.
The tribe uses sonar to determine the number of adult salmon returning to the Elwha River. Annually, from late January to the end of the run’s entry into the watershed in June, two sonar cameras are set up in the river to monitor the returning fish.
Sonar systems have been used since the 1960s to count fish migration, and with improved accuracy over time, sonar can now provide data that show direction of travel and length of fish.
In addition to sonar monitoring, the tribe has been determining species composition with tangle nets to establish the origin of fish returning to the river.
Surveyors walk along the mainstem of the Elwha River in the old Aldwell reservoir basin during the 2020 winter steelhead survey season. Photo: John McMillan. Story: Tiffany Royal