The Washington Department of Fish and Wildlife (WDFW) set a fish trap on the Wenatchee River this month to begin six months of monitoring juvenile salmon and steelhead.
The trap is located at the west Monitor Bridge on the south side of the river, just northwest of Wenatchee in Chelan County. Warning signs have been placed upstream of the trap and on cables supporting the trap. Rafters and other river users should use caution when floating nearby, although the width of the river at the site should provide relatively easy navigation.
The 24-foot-long, 8-foot-diameter cone-shaped trap will be operating through August, primarily at night when juvenile fish move downstream. WDFW personnel, who received support from the Chelan County Public Utility District in designing, building, and installing the trap, will check it every couple of hours when it is lowered in the river. Fish caught will be identified, measured, and released back into the river.
WDFW fish biologist and project lead Andrew Murdoch explained that the goal of the project is to estimate the number of naturally-produced juvenile salmon and steelhead migrating from the Wenatchee River basin to the Columbia River and eventually to the Pacific Ocean.
"Knowing the number of salmon and steelhead that survive to different life stages will help us better assess the habitat quality or productivity of the Wenatchee River basin and possibly predict with a higher degree of accuracy the number of returning adults," Murdoch said. "We'll also be able to understand what factors may limit the survival of these local stocks. Comparisons of survival rates between naturally-produced and hatchery-reared fish should also tell us how well our hatchery programs are performing."
Murdoch explained that WDFW has a good idea of the number of adult salmon and steelhead that return and spawn in the Wenatchee River basin each year, but natural production is unknown at this time. The monitoring project is expected to provide an estimate of the number of juvenile steelhead, spring chinook, summer chinook, and sockeye salmon that were produced in the Wenatchee River basin.