Hatchery Origin Strays Within the John Day River Steelhead Spawning Population Chris Bare1, Ian Tattam2, and Jim Ruzycki2 1 Oregon Department of Fish and Wildlife, 305 N Canyon Blvd, Canyon City, Oregon 97820 2 Oregon Department of Fish and Wildlife, 203 Badgley Hall, EOU, La Grande, Oregon 97850 Chris Bare Ian Tattam
[email protected] [email protected] 35 INTRODUCTION RESULTS r² = 0.69 30 • The John Day River supports a wild population of 350 50 summer steelhead (Oncorhynchus mykiss) with no Hatchery 25 45 hatchery supplementation and is part of the Middle 300 Wild Spawners Columbia River summer steelhead Distinct Population 20 % Hatchery 40 Segment that was listed as threatened under the Fish 250 35 Endangered Species Act in 1999 15 30 200 • The introduction of eight dams and reservoirs in the 10 lower Columbia and Snake rivers led to high juvenile 25 150 mortality rates; one mitigation strategy to increase 20 % Hatchery Origin Hatchery % 5 survival of salmonids has been mass juvenile % Hatchery transportation 100 15 Wild and and Hatchery Wild 0 10 • While the use of barges to transport smolts reduces 0 25 50 75 100 50 % Barged Hatchery Steelhead mortality associated with turbines and vulnerability to 5 predators, studies reveal the process may interfere 0 0 Figure 5. Relationship between the percentage of barged with juvenile olfactory imprinting: a process necessary '04 '05 '06 '07 '08 '09 '10 '11 '12 '13 '14 '15 '16 '17 hatchery steelhead smolts and percentage of hatchery for returning adults to home to natal streams Year origin spawners observed in the John Day River basin from 2004 to 2017.