Steelhead “Recycling” to Improve Angler Opportunity: How Can We Alter These Programs to Maximize Harvest and Minimize Impacts to Native Populations?

Each year, hundreds of thousands of adult salmon Oncorhynchus spp. and steelhead O. mykiss return to hatcheries throughout the Pacific Northwest. As broodstock quotas are met, a surplus of hatchery fish often exists, and recycling—the capture, transport, and then release of adult hatchery fishes back downstream—is used to increase angler opportunity in some locations. Recycled fishes that avoid harvest can remain in river systems, a concern in the Willamette River Basin, Oregon where non-native summer steelhead are recycled in tributaries that also have ESA-listed native winter steelhead populations. From 2012-2014, we radio-tagged 444 recycled summer steelhead in two Willamette River sub-basins to estimate behavior, distribution and fate of recycled summer steelhead. Telemetry records indicated that approximately 50% of radio-tagged recycled fish released in the South Santiam and Middle Fork Willamette Rivers were last detected in these tributaries, 9% and 18%, respectively, were reported harvested by anglers, and 9-26% strayed from their respective release tributary. Our data will allow managers to make more informed decisions on how to maximize harvest of these recycled fish while at the same time minimizing the impacts to native winter steelhead in the Willamette River Basin.